The DOI matches its Crossref record; 78 of the 78 references it cites were found in a registry or an index; 12 of the 59 sources its claims cite were checked for support.
Metabolic costs and evolutionary implications of human brain development
Open accessAbstract
The high energetic costs of human brain development have been hypothesized to explain distinctive human traits, including exceptionally slow and protracted preadult growth. Although widely assumed to constrain life-history evolution, the metabolic requirements of the growing human brain are unknown. We combined previously collected PET and MRI data to calculate the human brain's glucose use from birth to adulthood, which we compare with body growth rate. We evaluate the strength of brain-body metabolic trade-offs using the ratios of brain glucose uptake to the body's resting metabolic rate (RMR) and daily energy requirements (DER) expressed in glucose-gram equivalents (glucosermr% and glucoseder%). We find that glucosermr% and glucoseder% do not peak at birth (52.5% and 59.8% of RMR, or 35.4% and 38.7% of DER, for males and females, respectively), when relative brain size is largest, but rather in childhood (66.3% and 65.0% of RMR and 43.3% and 43.8% of DER). Body-weight growth (dw/dt) and both glucosermr% and glucoseder% are strongly, inversely related: soon after birth, increases in brain glucose demand are accompanied by proportionate decreases in dw/dt. Ages of peak brain glucose demand and lowest dw/dt co-occur and subsequent developmental declines in brain metabolism are matched by proportionate increases in dw/dt until puberty. The finding that human brain glucose demands peak during childhood, and evidence that brain metabolism and body growth rate covary inversely across development, support the hypothesis that the high costs of human brain development require compensatory slowing of body growth rate.
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30 Own result · 19 No full text of the sources · 11 Own interpretation · 5 Partly supported · 4 Own method · 3 Supported so far · 2 Supported · 2 Sources not found · 2 Not checked yet · 2 No basis given · 1 Not supported · accuracy not yet measured
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“pointing to an important role of aerobic glycolysis in support of synaptic proliferation and growth (28,30).”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
What the sources say
- Supportedcites [28] 28. Goyal MS, Hawrylycz M, Miller JA, Snyder AZ, Raichle ME (2014) Aerobic glycolysis in the human brain is associated with development and neotenous gene expression. Cell Metab 19(1):49-57. source
The Discussion states that aerobic glycolysis correlates with gene expression related to synapse formation and neurite growth, and suggests that it provides biosynthetic support for those processes. This supports the citing sentence’s inference of an important role, while the paper notes that its findings do not establish causation. (LLM, conf=0.90)
- Not checked — no full text of the sourcecites [30] 30. Bauernfeind AL, et al. (2014) Aerobic glycolysis in the primate brain: Reconsidering the implications for growth and maintenance. Brain Struct Funct 219(4):1149-1167. source
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“This shift in the social context of human child rearing, occurring together with a protracted postnatal development of cortical connectivity (54,55), likely created new opportunities for imitative learning and cumulative, intergenerational development of cultural traditions to become central features of the human adaptive complex (56,57).”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
What the sources say
- Supportedcites [54] 54. Miller DJ, et al. (2012) Prolonged myelination in human neocortical evolution. Proc Natl Acad Sci USA 109(41):16480-16485. source
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- Not checked — no full text of the sourcecites [55] 55. Bufill E, Agustí J, Blesa R (2011) Human neoteny revisited: The case of synaptic plas- ticity. Am J Hum Biol 23(6):729-739. source
- Partly supportedcites [56] 56. Boyd R, Richerson PJ, Henrich J (2011) The cultural niche: Why social learning is es- sential for human adaptation. Proc Natl Acad Sci USA 108(Suppl 2):10918-10925. sourceExperimental — accuracy not yet measured
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- Not checked — no full text of the sourcecites [57] 57. Hill K, Barton M, Hurtado AM (2009) The emergence of human uniqueness: Charac- ters underlying behavioral modernity. Evol Anthropol 18(5):187-200. source
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“suggesting an important role for childhood energetics and substrate availability in diabetes development (62,63).”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
What the sources say
- Not checked — no full text of the sourcecites [62] 62. Ong KK (2006) Size at birth, postnatal growth and risk of obesity. Horm Res 65:(Suppl 3):65-69. source
- Partly supportedcites [63] 63. Norris SA, et al.; COHORTS Group (2012) Size at birth, weight gain in infancy and childhood, and adult diabetes risk in five low-or middle-income country birth co- horts. Diabetes Care 35(1):72-79. sourceExperimental — accuracy not yet measured
The Conclusions (no page provided) link lower birth weight and accelerated weight gain after 48 months with adult glucose intolerance, supporting a role for early growth patterns in diabetes risk. The paper did not measure childhood energetics or substrate availability directly, and it found no increased glucose-intolerance risk from greater infant or early-childhood weight gain. (LLM, conf=0.82)
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“and when the energetic buffer of body fat stores are near their lifetime nadir (18).”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
What the sources say
- Not checked — no full text of the sourcecites [18] 18. Kuzawa CW (1998) Adipose tissue in human infancy and childhood: An evolutionary perspective. Am J Phys Anthropol 107(Suppl 27):177-209. source
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“The relationships that we document between age changes in brain glucose demands and body-weight growth rate are particularly striking in males, who maintain these inverse linear trends despite experiencing threefold changes in brain glucose demand and body growth rate between 6 mo and 13 y of age.”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
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“Body-weight growth (dw/dt) and both glucose rmr% and glucose der% are strongly, inversely related: soon after birth, increases in brain glucose demand are accompanied by proportionate decreases in dw/dt.”
§ Metabolic costs and evolutionary implications of human brain development > Abstract
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“In females, an earlier onset of pubertal weight gain leads to earlier deviations from similar linear inverse relationships.”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
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“In the modern human sample evaluated here, an average gram of brain tissue at 4 y uses more than 2.5-times the glucose of a gram of brain at birth (see data in SI Appendix, Tables S1 and S2).”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
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“we find a more complex pattern of substrate tradeoff.”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
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“then rises to a lifetime peak of 66.3% and 65.0% of RMR by 4.2-4.4y”
§ Metabolic costs and evolutionary implications of human brain development > Results
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“Daily glucose use by the brain peaks at 5.2 y of age at 167.0 g/d and 146.1 g/d in males and females, respectively.”
§ Metabolic costs and evolutionary implications of human brain development > Results
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“we find that peak brain glucose uptake occurs after the age of complete weaning from breast milk in most human societies (4)”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
What the sources say
- Not checked — no full text of the sourcecites [4] 4. Sellen D, Smay D (2001) Relationship between subsistence and age at weaning in "preindustrial" societies. Hum Nat 12(1):47-87. source
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“ages of declining brain glucose uptake in late childhood and early adolescence are accompanied by proportionate increases in weight growth.”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
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“glucose der% accounted for the equivalent of 35.4% and 38.7% of DER at birth”
§ Metabolic costs and evolutionary implications of human brain development > Results
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“We find that glucose rmr% and glucose der% do not peak at birth (52.5% and 59.8% of RMR, or 35.4% and 38.7% of DER, for males and females, respectively), when relative brain size is largest, but rather in childhood (66.3% and 65.0% of RMR and 43.3% and 43.8% of DER).”
§ Metabolic costs and evolutionary implications of human brain development > Abstract
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“After the childhood peak in brain glucose demands, each subsequent age-related decline in glucose rmr% is accompanied by a proportionate increase in dw/dt until onset of pubertal weight gain (∼12-13 y in males and ∼9-10 y in females)”
§ Metabolic costs and evolutionary implications of human brain development > Results
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“declined to 24.7% and 26.8% by 7 mo”
§ Metabolic costs and evolutionary implications of human brain development > Results
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“our PET-based calculations reveal that the magnitude of brain glucose uptake, both in absolute terms and relative to the body's metabolic budget, does not peak at birth but rather in childhood”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
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“Our findings agree with past estimates indicating that the brain dominates the body's metabolism during early life (31).”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
What the sources say
- Not checked — no full text of the sourcecites [31] 31. Holliday MA (1971) Metabolic rate and organ size during growth from infancy to maturity and during late gestation and early infancy. Pediatrics 47(Suppl 2):169-179. source
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“Collectively, this large increase in glucose uptake corresponds closely with the age of slowest body-weight growth.”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
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“adult brain glucose requirements are only half those at age 5 y.”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
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“Absolute brain glucose requirements peak at ∼5 y, several years before final brain size is achieved”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
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“Beginning around 6 mo, increases in relative glucose use are matched by proportionate decreases in weight growth”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
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“Adult glucose rmr% was 19.1% and 24.0% whereas glucose der% was 10.9% and 15.0% in males and females, respectively.”
§ Metabolic costs and evolutionary implications of human brain development > Results
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“drops to 37.5 and 40.8% of RMR in the first half-year”
§ Metabolic costs and evolutionary implications of human brain development > Results
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“after which slower growth is accompanied by declining glucose rmr% as both body size and brain metabolism approach adult levels.”
§ Metabolic costs and evolutionary implications of human brain development > Results
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“Ages of peak brain glucose demand and lowest dw/dt co-occur and subsequent developmental declines in brain metabolism are matched by proportionate increases in dw/dt until puberty.”
§ Metabolic costs and evolutionary implications of human brain development > Abstract
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“subsequent developmental declines in brain metabolism are matched by proportionate increases in dw/dt until puberty.”
§ Metabolic costs and evolutionary implications of human brain development > Abstract
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“In sum, we find that the rate of glucose uptake by the human brain, in both absolute terms and relative to the body's metabolic expenditure, does not peak at birth, when the size of the brain relative to the body is largest, but in childhood, when synaptic densities and related metabolic processes are maximal.”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
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“The present finding that the brain's requirement for glucose peaks after weaning, at an age when body fat stores are minimal (18)”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
What the sources say
- Not checked — no full text of the sourcecites [18] 18. Kuzawa CW (1998) Adipose tissue in human infancy and childhood: An evolutionary perspective. Am J Phys Anthropol 107(Suppl 27):177-209. source
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“These new estimates show that the ages when substrate trade-offs between the brain and body are greatest in humans coincide developmentally with the ages of slowest childhood body-weight growth”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
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“and that age-related changes in relative brain glucose needs and body-weight gain are tightly, inversely related from early infancy until puberty.”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
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“current data on hominin dental emergence, enamel growth rate, and skeletal growth suggest that a more extended period between weaning and sexual maturity began to appear at least 1.5 million y ago in Homo erectus (45).”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
What the sources say
- Not checked — no full text of the sourcecites [45] 45. Dean MC, Lucas VS (2009) Dental and skeletal growth in early fossil hominins. Ann Hum Biol 36(5):545-561. source
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“In light of this finding, it seems likely that the evolution of human encephalization required cultural or social strategies to buffer the energy intake of dependent offspring.”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
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“recent studies of total energy expenditure (TEE) show that typical physical activity levels (PAL = TEE/RMR) for preschool age children (3-5 y) are lower than in later childhood and adolescence (38,39,42).”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
What the sources say
- Not matchedcites [38] 38. Food and Agriculture Organization & World Health Organization (2004) Human En- ergy Requirements: Report of a Joint FAO/WHO/UNU Expert Consultation (Food and Agricultural Organization of the United Nations, Rome).
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
- Not matchedcites [39] 39. Institute of Medicine, Panel on Macronutrients (2005) Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (National Academies Press, Washington, DC).
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- Not checked — no full text of the sourcecites [42] 42. Butte NF, et al. (2014) Revision of dietary reference intakes for energy in preschool- age children. Am J Clin Nutr 100(1):161-167. source
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“Our findings complement these data and implicate the high energy and substrate requirements of the brain, especially during the ages of most rapid development and learning, as a likely cause of life-history differences between humans and other closely related primates, such as chimpanzees.”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
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“These findings suggest that, like the body's very low expenditure on somatic growth, activity-related (discretionary) expenditure during human development is also comparatively low at ages of peak brain metabolic demand.”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
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“Comparative growth data support this prediction (41), showing that, unlike humans, chimpanzees and other great apes do not display marked declines in weight velocities after infancy.”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
What the sources say
- Not checked — no full text of the sourcecites [41] 41. Leigh SR (1996) Evolution of human growth spurts. Am J Phys Anthropol 101(4): 455-474. source
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“In all three species neocortical synapse densities are doubled during growth, compared with densities at birth.”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
What the sources say
- Not checked — no full text of the sourcecites [44] 44. Bianchi S, et al. (2013) Synaptogenesis and development of pyramidal neuron den- dritic morphology in the chimpanzee neocortex resembles humans. Proc Natl Acad Sci USA 110(Suppl 2):10395-10401. source
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“This uncoupling of the energetic requirements of the brain from brain size reflects developmental dynamics in substrate-intensive processes related to neural plasticity and learning, which are not preserved in fossil samples.”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
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“Our results also highlight underappreciated implications of the high glucose requirements of the human brain for medicine and public health.”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
plain- Asserted: passes — The authors put it forward as true.
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- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“points to strong selection on physiologic mechanisms to redirect glucose delivery to the brain during nutritional stress.”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
boosteddirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
In the paper
“The age of the trough in body-weight growth rate estimated from the cross-sectional data used here is consistent with mixedlongitudinal reference data showing lowest rates of weight gain from 4 to 4.5 y (66)”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
What the sources say
- Not checked — no full text of the sourcecites [66] 66. Baumgartner RN, Roche AF, Himes JH (1986) Incremental growth tables: Supple- mentary to previously published charts. Am J Clin Nutr 43(5):711-722. source
hedgedcorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“These findings thus provide rare empirical support for the hypothesis that humans evolved a protracted period of slow preadult growth to compensate for the unusually high metabolic costs of brain development underlying the extraordinary human capacity for cultural learning.”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
boosteddirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A claim is checked only against the cited paper’s full text, never its abstract, and none is available for its sources.
In the paper
“Although an important precursor to type 2 diabetes, peripheral insulin resistance is also effective at shunting scarce glucose to high-demand tissues or organs, such as to the fetus during the mild diabetes of pregnancy (58), or to the brain during the insulin-resistance triggered by stress (59).”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
What the sources say
- Not checked — no full text of the sourcecites [58] 58. Haig D (1993) Genetic conflicts in human pregnancy. Q Rev Biol 68(4):495-532. source
- Not checked — no full text of the sourcecites [59] 59. Kuzawa CW (2010) Beyond feast-famine: Brain evolution, human life history, and the metabolic syndrome. Human Evolutionary Biology, ed Muehlenbein M (Cam- bridge Univ Press, Cambridge). source
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A claim is checked only against the cited paper’s full text, never its abstract, and none is available for its sources.
In the paper
“recent comparative analyses suggest that cooperative care in raising and provisioning young was likely important in achieving levels of encephalization seen in Homo sapiens (52,53).”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
What the sources say
- Not checked — no full text of the sourcecites [52] 52. Isler K, van Schaik CP (2012) How our ancestors broke through the grey ceiling: Comparative evidence for cooperative breeding in early Homo. Curr Anthropol 53(Suppl 6):S453-S465. source
- Not checked — no full text of the sourcecites [53] 53. Bogin B, Bragg J, Kuzawa C (2014) Humans are not cooperative breeders but practice biocultural reproduction. Ann Hum Biol 41(4):368-380. source
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
What the paper did — it cites no source for this, so there is none to check. The quote shows it is in the paper.
In the paper
“Importantly, the cross-sectional body weights that we use to calculate RMR and the brain masses used to calculate brain glucose uptake were obtained from the same individuals”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“suggesting that our approach provides a useful basis for evaluating the changing relationship between brain metabolism and body size across a large sample varying widely in age and developmental stage.”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
hedged- Asserted: passes — The authors put it forward as true.
- Checkable: unclear — It is unclear whether it could be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
What the paper did — it cites no source for this, so there is none to check. The quote shows it is in the paper.
In the paper
“Because the MRI estimates before and after 4.6 y of age were derived from different populations with different body and brain sizes, it was not possible to splice absolute brain-region volumes to form single birth-adulthood growth curves.”
§ Metabolic costs and evolutionary implications of human brain development > Materials and Methods
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Probably not a substantial claim. 12
- It may state two separate claims as one. 20
- The quote only partly states this claim. 1
At least one cited source doesn’t support this claim or points to a different paper, and none confirmed it — see the verdicts below.
In the paper
“Studies report interactions between fetal undernutrition or small birth size and childhood weight gain as predictors of diabetes risk”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
What the sources say
- Not checked — no full text of the sourcecites [62] 62. Ong KK (2006) Size at birth, postnatal growth and risk of obesity. Horm Res 65:(Suppl 3):65-69. source
- Disputedcites [63] 63. Norris SA, et al.; COHORTS Group (2012) Size at birth, weight gain in infancy and childhood, and adult diabetes risk in five low-or middle-income country birth co- horts. Diabetes Care 35(1):72-79. sourceExperimental — accuracy not yet measured
The Results section, “SGA and the associations of weight gain with outcomes” (page unavailable), directly tested whether small-for-gestational-age status or birth weight interacted with conditional weight gain. It found no significant interactions at any age. The paper reports birth weight and later weight gain as separate risk factors, not interacting predictors. (LLM, conf=0.91)
Checked by a reasoning model — may be wrong.
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it.
The sources with a verdict support this claim; the rest weren’t checked yet, have no full text we could read, or their verdicts aren’t rated yet.
In the paper
“Rudimentary hunting and gathering economies appeared with the emergence of the genus Homo and are believed to have been important in supporting early brain expansion (49)(50)(51).”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
What the sources say
- Not checked — no full text of the sourcecites [49] 49. Bunn H (2006) Meat made us human. Evolution of the Human Diet: The Known, the Unknown, and the Unknowable, ed Unger P (Oxford Univ Press, New York), pp 191-211. source
- Supportedcites [50] 50. Plummer T (2004) Flaked stones and old bones: Biological and cultural evolution at the dawn of technology. Am J Phys Anthropol 125(Suppl 39):118-164. source
The ‘Bridging Subsistence and Sociality’ section describes early Homo foraging that included hunting or scavenging and plant foods, and links its first major increase in cranial capacity possibly to more animal tissue in the diet. The Conclusions identify meat and nutrient-dense plant foods as the likely diet fueling brain expansion in Homo. Page numbers are unavailable in our copy. (LLM, conf=0.87)
- Not checked — no full text of the sourcecites [51] 51. Pobiner BL, Rogers MJ, Monahan CM, Harris JW (2008) New evidence for hominin carcass processing strategies at 1.5 Ma, Koobi Fora, Kenya. J Hum Evol 55(1):103-130. source
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“Data on dental eruption point to coevolution between brain expansion and maturational delay (45,46), with a fully modern pattern of delayed physical growth not emerging until the origin of anatomically modern humans (47,48).”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
What the sources say
- Not checked — no full text of the sourcecites [45] 45. Dean MC, Lucas VS (2009) Dental and skeletal growth in early fossil hominins. Ann Hum Biol 36(5):545-561. source
- Not checked — no full text of the sourcecites [46] 46. Dean C, et al. (2001) Growth processes in teeth distinguish modern humans from Homo erectus and earlier hominins. Nature 414(6864):628-631. source
- Partly supportedcites [47] 47. Smith TM, et al. (2007) Earliest evidence of modern human life history in North African early Homo sapiens. Proc Natl Acad Sci USA 104(15):6128-6133. sourceExperimental — accuracy not yet measured
The Abstract identifies a 160,000-year-old early H. sapiens juvenile as the oldest-known Homo specimen with dental development more similar to modern humans than to earlier Homo. But it explicitly says when the prolonged modern human developmental pattern originated is unknown. The paper therefore supports evidence of delayed development in early H. sapiens, not the categorical claim that it first emerged with anatomically modern humans. (LLM, conf=0.88)
- Not checked — no full text of the sourcecites [48] 48. Smith TM, et al. (2010) Dental evidence for ontogenetic differences between modern humans and Neanderthals. Proc Natl Acad Sci USA 107(49):20923-20928. source
hedgedcorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
The sources with a verdict support this claim; the rest weren’t checked yet, have no full text we could read, or their verdicts aren’t rated yet.
In the paper
“Recent work shows that glucose uptake outpaces oxygen use in the human brain, and that this imbalance also peaks at the age of greatest glucose uptake in childhood”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
What the sources say
- Supportedcites [28] 28. Goyal MS, Hawrylycz M, Miller JA, Snyder AZ, Raichle ME (2014) Aerobic glycolysis in the human brain is associated with development and neotenous gene expression. Cell Metab 19(1):49-57. source
The Results section’s meta-analysis reports that brain glucose consumption exceeds the amount expected from oxygen consumption and that this excess peaks around age 5, when total glucose consumption is also highest. The Methods section explains that oxygen consumption was converted to its glucose equivalent for this comparison; the claim is not comparing the raw quantities in different units. (LLM, conf=0.92)
- Not checked — no full text of the sourcecites [30] 30. Bauernfeind AL, et al. (2014) Aerobic glycolysis in the primate brain: Reconsidering the implications for growth and maintenance. Brain Struct Funct 219(4):1149-1167. source
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- Supported
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“These patterns suggest that peak brain glucose uptake during childhood reflects neuronal plasticity in the cerebral cortex (32), which involves overproliferation of energetically costly dendritic arbors and synapses before activity-dependent pruning (33,34).”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
What the sources say
- Not checked — no full text of the sourcecites [32] 32. Chugani HT, Phelps ME, Mazziotta JC (1987) Positron emission tomography study of human brain functional development. Ann Neurol 22(4):487-497. source
- Partly supportedcites [33] 33. Petanjek Z, et al. (2011) Extraordinary neoteny of synaptic spines in the human pre- frontal cortex. Proc Natl Acad Sci USA 108(32):13281-13286. sourceExperimental — accuracy not yet measured
The opening section (p. 1) describes initially overproduced cortical synapses followed by activity-dependent selective elimination, and reports that prefrontal dendritic spine density in childhood is two to three times adult levels. It does not establish overproliferation of dendritic arbors or describe these structures as energetically costly. The glucose-uptake interpretation is attached to citation (32), not to this source's citation (33 or 34). (LLM, conf=0.87)
- Not checked — no full text of the sourcecites [34] 34. Huttenlocher PR (1979) Synaptic density in human frontal cortex -Developmental changes and effects of aging. Brain Res 163(2):195-205. source
hedgeddirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
Every source the paper cites for this claim was checked and supports it.
In the paper
“Pontzer et al. (43) recently showed that humans and other primates have reduced TEEs for their body sizes, despite having basal metabolic rates (BMRs) consistent with those of other mammals.”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
What the sources say
- Supportedcites [43] 43. Pontzer H, et al. (2014) Primate energy expenditure and life history. Proc Natl Acad Sci USA 111(4):1433-1437. source
The Results and Discussion report that primate TEE was about half that expected for body mass, while primate BMR was similar to that of other placental mammals. The same section notes marginally lower BMR in strepsirrhines, and the Submission PDF states that humans fit the low-TEE primate pattern. (LLM, conf=0.93)
boostedcorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim.
- Supported
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“An additional limitation is that our analyses are based on cross-sectional brain and body-weight data, which pool fast-and slow-maturing individuals; this pooling can attenuate the apparent magnitude of the pubertal growth spurt while also obscuring the variable timings of its onset (65).”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
What the sources say
- Partly supportedcites [65] 65. Tanner JM, Whitehouse RH (1976) Clinical longitudinal standards for height, weight, height velocity, weight velocity, and stages of puberty. Arch Dis Child 51(3):170-179. sourceExperimental — accuracy not yet measured
The paper’s Abstract (page not supplied) says cross-sectional standards can mislead because some children have adolescent growth spurts early and others late, supporting the concern that pooling obscures individual timing. It also says the difference from longitudinal standards is especially marked for growth velocity, but does not state that pooling attenuates the apparent magnitude of the spurt. The citing authors’ description of their own brain and body-weight data is not a finding attributed to this source. (LLM, conf=0.82)
plainconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- Partly supported
Every source the paper cites for this claim was checked and supports it.
In the paper
“Although normative data on developmental changes in insulin sensitivity during child development are lacking (64)”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
What the sources say
- Supportedcites [64] 64. Levy-Marchal C, et al.; ESPE-LWPES-ISPAD-APPES-APEG-SLEP-JSPE; Insulin Resistance in Children Consensus Conference Group (2010) Insulin resistance in children: Con- sensus, perspective, and future directions. J Clin Endocrinol Metab 95(12):5189-5198. source
In the section headed “2. Insulin resistance is a continuum” (page unavailable), the paper says cohort sizes are insufficient to establish normative distributions for insulin sensitivity in children. It also says separate standards would need to be developed for different pubertal stages, supporting the claim that normative developmental data are lacking. (LLM, conf=0.87)
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it.
- Supported
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“These values represent 1.88-and 1.82-times the daily glucose use of the brain in adulthood”
§ Metabolic costs and evolutionary implications of human brain development > Results
plainn = 29- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
The quote only partly states this claim.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Very similar results were obtained when brain glucose was evaluated in relation to DER”
§ Metabolic costs and evolutionary implications of human brain development > Results
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it.
In the paper
“The childhood peak in brain glucose uptake is greatest in the cerebrum, and less pronounced in the brainstem and cerebellum (32).”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
What the sources say
- Not checked — no full text of the sourcecites [32] 32. Chugani HT, Phelps ME, Mazziotta JC (1987) Positron emission tomography study of human brain functional development. Ann Neurol 22(4):487-497. source
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Starting at 6 mo, each increase in glucose rmr% is matched by a proportionate decrease in dw/dt, with peak glucose rmr% and the trough of dw/dt cooccurring.”
§ Metabolic costs and evolutionary implications of human brain development > Results
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“when the glucose used by the brain comprises the equivalent of 66% of the body's RMR, and roughly 43% of total expenditure.”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“In males and females, respectively, total brain glucose uptake is the equivalent of 52.5% and 59.8% of RMR at birth”
§ Metabolic costs and evolutionary implications of human brain development > Results
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Adult glucose rmr% was 19.1% and 24.0% whereas glucose der% was 10.9% and 15.0% in males and females, respectively.”
§ Metabolic costs and evolutionary implications of human brain development > Results
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“before rising to peak levels of 43.3% at 3.8 y (males) and 43.8% at 4 y (females)”
§ Metabolic costs and evolutionary implications of human brain development > Results
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Both glucose rmr% and glucose der% decline in the first halfyear as a fast but decelerating pace of body growth established in utero initially outpaces postnatal increases in brain metabolism.”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A claim is checked only against the cited paper’s full text, never its abstract, and none is available for its sources.
In the paper
“A shift to calorically dense and easily digested foods, and greater food sharing among social groups, would have increased the nutritional quality and stability of the diet (14,15,20).”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
What the sources say
- Not checked — no full text of the sourcecites [14] 14. Foley RA, Lee PC (1991) Ecology and energetics of encephalization in hominid evo- lution. Philos Trans R Soc Lond B Biol Sci 334(1270):223-231, discussion 232. source
- Not checked — no full text of the sourcecites [15] 15. Leonard WR, Robertson ML (1992) Nutritional requirements and human evolution: A bioenergetics model. Am J Hum Biol 4(2):179-195. source
- Not checked — no full text of the sourcecites [20] 20. Aiello LC, Wheeler P (1995) The expensive-tissue hypothesis: The brain and the di- gestive system in human and primate evolution. Curr Anthropol 36(2):199-221. source
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
In the paper
“In macaques the period of peak synaptic density occurs during infancy, whereas in humans and chimpanzees peak synaptic densities take place during the midjuvenile or (in humans) childhood period (44).”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
What the sources say
- Not checked — no full text of the sourcecites [44] 44. Bianchi S, et al. (2013) Synaptogenesis and development of pyramidal neuron den- dritic morphology in the chimpanzee neocortex resembles humans. Proc Natl Acad Sci USA 110(Suppl 2):10395-10401. source
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A claim is checked only against the cited paper’s full text, never its abstract, and none is available for its sources.
In the paper
“Whereas past attempts to quantify the contribution of the brain to the body's metabolic expenditure suggested that the brain accounted for a continuously decreasing fraction of RMR as the brain-to-body weight ratio declined with age (25,31)”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
What the sources say
- Not checked — no full text of the sourcecites [25] 25. Holliday MA (1986) Body composition and energy needs during growth. Human Growth: A Comprehensive Treatise, Vol 2 Postnatal Growth, eds Falkner F, Tanner JM (Plenum, New York), 2 Ed, pp 117-139. source
- Not checked — no full text of the sourcecites [31] 31. Holliday MA (1971) Metabolic rate and organ size during growth from infancy to maturity and during late gestation and early infancy. Pediatrics 47(Suppl 2):169-179. source
hedgeddirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim.
None of the sources cited for this claim have been checked yet.
In the paper
“It is notable that the increase in body growth rate at puberty-which is unusually pronounced in humans-is deferred to an age when brain glucose uptake is greatly reduced (1,26,41).”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
What the sources say
- Not matchedcites [1] 1. Bogin B (1999) Patterns of Human Growth (Cambridge Univ Press, Cambridge, UK), 2nd Ed.
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
- Not checked — no full text of the sourcecites [26] 26. Aiello LC, Wells JCK (2002) Energetics and the evolution of the genus Homo. Annu Rev Anthropol 31:323-328. source
- Not checked — no full text of the sourcecites [41] 41. Leigh SR (1996) Evolution of human growth spurts. Am J Phys Anthropol 101(4): 455-474. source
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- Not matched
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“We interpret our finding of an inverse relationship between the brain's demand for glucose and body-weight growth rate as support for the hypothesis that human brain development is sufficiently costly to require a compensatory reduction in expenditure on body growth, thus helping explain our unusually slow rate of childhood growth and resultant delay in attainment of adult size and sexual maturity”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
hedgeddirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
In the paper
“Brain energetics are thus not likely to impose a strong constraint on later juvenile body growth in macaques, whereas in chimpanzees growth is predicted to be slowed in the juvenile period, but to a lesser degree than in humans because of their smaller brains and corresponding lower brain metabolic needs (22).”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
What the sources say
- Not checked — no full text of the sourcecites [22] 22. Leigh SR (2004) Brain growth, life history, and cognition in primate and human evolution. Am J Primatol 62(3):139-164. source
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The finding that human brain glucose demands peak during childhood, and evidence that brain metabolism and body growth rate covary inversely across development, support the hypothesis that the high costs of human brain development require compensatory slowing of body growth rate.”
§ Metabolic costs and evolutionary implications of human brain development > Abstract
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
In the paper
“despite having similar cranial capacities, dental eruption data suggest that Neanderthals grew more rapidly than modern humans (48).”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
What the sources say
- Not checked — no full text of the sourcecites [48] 48. Smith TM, et al. (2010) Dental evidence for ontogenetic differences between modern humans and Neanderthals. Proc Natl Acad Sci USA 107(49):20923-20928. source
hedgedcorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it.
In the paper
“It has been noted that the high and inflexible glucose requirements of the developing human brain make it susceptible to impairment from nutritional shortfall (18).”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
What the sources say
- Not checked — no full text of the sourcecites [18] 18. Kuzawa CW (1998) Adipose tissue in human infancy and childhood: An evolutionary perspective. Am J Phys Anthropol 107(Suppl 27):177-209. source
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim.
In the paper
“and the latest World Health Organization (WHO) report on human energy requirements similarly finds that caloric needs for body growth are lowest at 4-5 y (38).”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
What the sources say
- Not matchedcites [38] 38. Food and Agriculture Organization & World Health Organization (2004) Human En- ergy Requirements: Report of a Joint FAO/WHO/UNU Expert Consultation (Food and Agricultural Organization of the United Nations, Rome).
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it.
- Not matched
A claim is checked only against the cited paper’s full text, never its abstract, and none is available for its sources.
In the paper
“A system in which extended social networks provisioned food for children, combined with shifts to calorically dense and easily digested foods procured through hunting (14,15), would have allowed the costs of human brain development to be widely distributed and also buffered against shortfall.”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
What the sources say
- Not checked — no full text of the sourcecites [14] 14. Foley RA, Lee PC (1991) Ecology and energetics of encephalization in hominid evo- lution. Philos Trans R Soc Lond B Biol Sci 334(1270):223-231, discussion 232. source
- Not checked — no full text of the sourcecites [15] 15. Leonard WR, Robertson ML (1992) Nutritional requirements and human evolution: A bioenergetics model. Am J Hum Biol 4(2):179-195. source
hedgeddirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A claim is checked only against the cited paper’s full text, never its abstract, and none is available for its sources.
In the paper
“Changes in insulin secretion are believed to help coordinate glucose delivery to the brain as brain size and energy requirements change during development (60,61).”
§ Metabolic costs and evolutionary implications of human brain development > Discussion
What the sources say
- Not checked — no full text of the sourcecites [60] 60. Kubera B, et al. (2013) Energy allocation between brain and body during ontogenetic development. Am J Hum Biol 25(6):725-732. source
- Not checked — no full text of the sourcecites [61] 61. Peters A, et al. (2004) The selfish brain: Competition for energy resources. Neurosci Biobehav Rev 28(2):143-180. source
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it.
What the paper did — it cites no source for this, so there is none to check. The quote shows it is in the paper.
In the paper
“The lCMRGlc values in the 29 children were compared with those of the seven healthy young adult volunteers, whose detailed neurological and psychological examinations disclosed no abnormalities.”
§ Metabolic costs and evolutionary implications of human brain development > Materials and Methods
plainn = 29- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it.
In the paper
“Because RMR was estimated from WHO age-and sex- specific predictive equations, there were discontinuities at the ages corre- sponding to changes in the predictive equations (at 3 and 10 y of age) (SI Appendix, Fig. S4).”
§ Metabolic costs and evolutionary implications of human brain development > Calculation of Glucose rmr% and Glucose der% .
What the sources say
- Not matchedcites [38] 38. Food and Agriculture Organization & World Health Organization (2004) Human En- ergy Requirements: Report of a Joint FAO/WHO/UNU Expert Consultation (Food and Agricultural Organization of the United Nations, Rome).
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it.
- Not matched
What the paper did — it cites no source for this, so there is none to check. The quote shows it is in the paper.
In the paper
“Written informed consent for the PET procedures was obtained directly from adult participants, and for minors, from parents, with institutional review board oversight by the University of California at Los Angeles Human Subject Protection Committee.”
§ Metabolic costs and evolutionary implications of human brain development > Materials and Methods
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.
The paper relies on this without support.
The Dekaban and Sadowsky brain-weight series is the only available data series that reports brain and body weights from the same individuals and spans birth to adulthood.
“To our knowledge, this highly cited data series is the only one available that reports brain and body weights from the same individuals, and that spans birth to adulthood.”
The paper relies on this without support.
There is no study that includes PET and MRI data in the same healthy individuals spanning birth to adulthood, for ethical reasons.
“For ethical reasons, there is no study that includes PET and MRI data in the same healthy individuals spanning birth to adulthood.”
Claims other papers make about this one
Each is checked against this paper’s own text: does it say what the citing paper says it does?
In the citing paper
“Developing a large brain is energetically expensive and places a constraint on somatic growth(2).”
From The growth pattern of Neandertals, reconstructed from a juvenile skeleton from El Sidrón (Spain) (2017) · cites this paper as [2]
In the citing paper
“The unusually high cost of modern human brain development is greatest during the infant and childhood periods and seems to require a compensatory slowing of childhood body growth(2, 3).”
From The growth pattern of Neandertals, reconstructed from a juvenile skeleton from El Sidrón (Spain) (2017) · cites this paper as [2]
In the citing paper
“However, in large brained hominins like modern humans and Neandertals, an accelerated pace of brain growth, coincident with accelerated somatic growth, would impose a high energetic cost (2).”
From The growth pattern of Neandertals, reconstructed from a juvenile skeleton from El Sidrón (Spain) (2017) · cites this paper as [2]
Citations
Cites
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“such as centering of individual growth curves on maturational indices rather than chronological age (65), would require repeat PET imaging in healthy individuals, which, as noted, is not ethical.”
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Lunt, S. Y., & Vander Heiden, M. G. (2011) · Annual Review of Cell and Developmental Biology · doi:10.1146/annurev-cellbio-092910-154237 · Cited by 3,057
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Petanjek, Z., Judaš, M., Šimić, G., Rašin, M. R., Uylings, H. B. M., Rakic, P., & Kostović, I. (2011) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.1105108108 · Cited by 1,411
Grandmothering, menopause, and the evolution of human life histories
Hawkes, K., O’Connell, J. F., Jones, N. G. B., Alvarez, H., & Charnov, E. L. (1998) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.95.3.1336 · Cited by 1,343
The cultural niche: Why social learning is essential for human adaptation
Boyd, R., Richerson, P. J., & Henrich, J. (2011) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.1100290108 · Cited by 1,303
Research works printed but not linked: 1
- J Durnin Basal Metabolic Rate in Man. Report of a Joint FAO/WHO/UNU Expert Consultation on Energy and Protein Requirements (Univ of Glasgow, Glasgow, 1981).
Cited by
Sorted by citations
Human organoids: model systems for human biology and medicine
Kim, J., Koo, B.-K., & Knoblich, J. A. (2020) · Nature Reviews Molecular Cell Biology · doi:10.1038/s41580-020-0259-3 · Cited by 2,187
Brain charts for the human lifespan
Bethlehem, R. A. I., Seidlitz, J., White, S. R., Vogel, J. W., Anderson, K. M., Adamson, C., Adler, S., Alexopoulos, G. S., Anagnostou, E., Areces-Gonzalez, A., et al. (2022) · Nature · doi:10.1038/s41586-022-04554-y · Cited by 1,794
A Cellular Perspective on Brain Energy Metabolism and Functional Imaging
Magistretti, P. J., & Allaman, I. (2015) · Neuron · doi:10.1016/j.neuron.2015.03.035 · Cited by 1,285
“It also appears that brain energy metabolism is inversely correlated during development, suggesting that the high metabolic cost of brain function is compensated by a slowing of the body growth rate (Kuzawa et al., 2014).”
BackgroundBrain Glucose Metabolism: Integration of Energetics with Function
Dienel, G. A. (2018) · Physiological Reviews · doi:10.1152/physrev.00062.2017 · Cited by 911
Life History Theory and Evolutionary Psychology
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“Broadening the current perspective on life history trade-offs and decisions will be especially important in view of the disproportionate force of selection on early survival (Jones, 2009) and the severe metabolic trade-offs involved in brain growth through infancy and childhood (Kuzawa et al., 2014).”
Background
Metadata
- Authors
- Kuzawa, C. W., Chugani, H. T., Grossman, L. I., Lipovich, L., Muzik, O., Hof, P. R., Wildman, D. E., Sherwood, C. C., Leonard, W. R., & Lange, N.
- Affiliations
- Northwestern University (US)
- Children's Hospital of Michigan (US)
- Wayne State University (US)
- Department of Pediatrics,
- Icahn School of Medicine at Mount Sinai (US)
- University of Illinois Urbana-Champaign (US)
- George Washington University (US)
- Department of Anthropology,
- Harvard University (US)
- ORCID
- Venue
- Proceedings of the National Academy of Sciences
- Publisher
- National Academy of Sciences
- Published
- 2014-08-25
- Volume
- 111
- Issue
- 36
- Pages
- 13010-13015
- ISSN
- 0027-8424 (ISSN-L)
- 1091-6490
- PMC
- PMC4246958
- OpenAlex
- W2069193149
- Cited by
- 585
- References
- 74
- Citations by year
- 2026: 47 · 2025: 66 · 2024: 58 · 2023: 48 · 2022: 47 · 2021: 57 · 2020: 81 · 2019: 40 · 2018: 42 · 2017: 25 · 2016: 40 · 2015: 26 · 2014: 6
- FWCI
- 44.89
- Type
- journal article
- Language
- en
- Open access
- bronze
- doi.org
- Locations
- Proceedings of the National Academy of Sciences (publishedVersion)
- PubMed Central (publishedVersion)
- PubMed (publishedVersion)
- Funders
- National Science Foundation (0827531, 220020293, 0827546)
- James S. McDonnell Foundation (220020293)
- National Institutes of Health (n01ns092319-000, n01ns092317-000, n01ns92315-15-0-1, n01hd23343-8-0-0, n01ns092314-002, n01ns092316-000, n01ns092318-002, n01mh90002-26-0-0, NS034783)
- National Institute of Mental Health (N01-MH09-0002)
- National Institute of Neurological Disorders and Stroke (N01 NS092318, N01 NS002320, R56NS034783, N01 NS092316, N01 NS092314, N01 NS092315, N01 NS092317, N01 NS092319, R01NS034783)
- Eunice Kennedy Shriver National Institute of Child Health and Human Development (N01-HD023343)
- Topics
- Social Sciences › Psychology › Experimental and Cognitive Psychology › Evolutionary Psychology and Human Behavior
- Life Sciences › Agricultural and Biological Sciences › Ecology, Evolution, Behavior and Systematics › Primate Behavior and Ecology
- Life Sciences › Neuroscience › Developmental Neuroscience › Neurogenesis and neuroplasticity mechanisms
- Keywords
- human brain development, brain glucose uptake, resting metabolic rate, daily energy requirements, body growth rate, life history evolution, puberty
- MeSH terms
- Adult, Aging, Basal Metabolism, Body Weight, Brain, Biological Evolution, Female, Glucose, Humans, Male, Young Adult
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
A language model drew the claims from the paper on 2026-10-11, under version 3 of the claim definition (model deepseek-v4.1-flash, prompt extract-v3).
A second model labelled each claim on 2026-10-11 (model jev-1.13-20260917, definition revision gold-guideline-v0.2).
Cited sources are checked with a language model’s help (gpt-6-sol).
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
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