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Cited by 292Regulation of Appetite and ObesityDiet, Metabolism, and DiseaseObesity, Physical Activity, Diet

The carbohydrate-insulin model: A physiological perspective on the obesity pandemic

Open access
Ludwig, David S, Aronne, Louis J, Astrup, Arne, de Cabo, Rafael, Cantley, Lewis C, Friedman, Mark I, Heymsfield, Steven B, Johnson, James D +9 more·2021·The American Journal of Clinical Nutrition
DOI 10.1093/ajcn/nqab270PMC PMC8634575
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Abstract

According to a commonly held view, the obesity pandemic is caused by overconsumption of modern, highly palatable, energy-dense processed foods, exacerbated by a sedentary lifestyle. However, obesity rates remain at historic highs, despite a persistent focus on eating less and moving more, as guided by the energy balance model (EBM). This public health failure may arise from a fundamental limitation of the EBM itself. Conceptualizing obesity as a disorder of energy balance restates a principle of physics without considering the biological mechanisms that promote weight gain. An alternative paradigm, the carbohydrate-insulin model (CIM), proposes a reversal of causal direction. According to the CIM, increasing fat deposition in the body-resulting from the hormonal responses to a high-glycemic-load diet-drives positive energy balance. The CIM provides a conceptual framework with testable hypotheses for how various modifiable factors influence energy balance and fat storage. Rigorous research is needed to compare the validity of these 2 models, which have substantially different implications for obesity management, and to generate new models that best encompass the evidence.

AI snapshot

Written from the paper’s full text.

TL;DR

The paper argues that the carbohydrate-insulin model (CIM) reverses the conventional energy balance model: high-glycemic-load diets drive hormonal responses that promote fat deposition and thereby positive energy balance. It reviews supporting evidence, addresses criticisms, and calls for rigorous comparative research while acknowledging the model is incomplete.

Key findings

  • The CIM places dietary glycemic load centrally: high-GL meals increase insulin secretion, suppress glucagon, and elicit a GIP-dominant incretin response; after a 60% vs 20% carbohydrate meal, the integrated insulin-to-glucagon ratio was 7-fold higher in adults habituated to a high- vs low-carbohydrate diet.
  • Cited evidence includes that insulin-treated rats had increased fat mass despite controlled food intake; intensification of insulin therapy in type 1 diabetes for 2 mo was associated with a 2.4-kg increase in body fat; adipose-specific insulin receptor ablation in mice reduced adiposity without changing energy intake; and GIP receptor knockout mice were protected against diet-induced obesity.
  • Population-level context: common genetic variants may explain >20% of population-level BMI variation; the average US man weighed ∼75 kg in the 1960s and ∼90 kg today; the average weight increase over the last half century is attributable to storage of <1 g extra fat per day.
  • The paper states that the chronic effect of glycemic load on body composition in humans, with control for energy intake, has not been determined, and that long-term high-fat diets resulted in more weight loss than high-carbohydrate diets in cited studies.

Methods

  • Narrative review and conceptual synthesis, not a systematic review or primary experiment; it formulates the CIM, compares it with the energy balance model, and specifies testable hypotheses.
  • Evidence base consists of cited laboratory animal and human studies, clinical trials, observational and Mendelian randomization studies, and historical quotations in Table 1; no new sample or dataset is presented.
  • Main analysis is a mechanistic and conceptual argument organized around Figure 1 and numbered hypotheses, followed by responses to criticisms and proposed research priorities.

Limitations

  • Stated: the iteration of the CIM presented “cannot provide a complete and precise representation of all causal mechanisms” and “nor does it preclude the existence of other causative influences”; definitive research is challenging because the average weight increase over the last half century reflects storage of <1 g extra fat per day.
  • Stated: the chronic effect of glycemic load on human body composition, with control for energy intake, has not been determined.
  • Evident from the text: as a narrative review, evidence selection and interpretation may reflect the authors’ perspective, with no systematic search or quantitative synthesis; many cited findings come from animal models or short-term human studies, and the paper itself notes that short-term studies may mislead about chronic macronutrient effects.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1093/ajcn/nqab270

Cites

168 of 168 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

0 of 138 cited sources checked · 0 supported · 0 flagged

  • Findingreasoning

    The metabolic effects of diet, such as on substrate partitioning, do not feature in these iterations of the EBM.

    “The metabolic effects of diet, such as on substrate partitioning—a key distinguishing aspect of the CIM—do not feature in these iterations of the EBM.”
    Quote in the paperSubstantial claim
  • Interpretationnone given

    The CIM better reflects knowledge on the biology of body weight control than the EBM.

    “argue that the CIM better reflects knowledge on the biology of body weight control than the EBM”
    Quote in the paperNot a substantial claim
  • Premisecitation

    Surprisingly little evidence relates palatability directly to chronic overconsumption in laboratory animals or humans under normal conditions.

    “However, surprisingly little evidence relates palatability directly to chronic overconsumption (i.e., relative to energy requirements) in laboratory animals or humans under normal conditions (10–12).”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites [10] Tordoff, 2017, Does eating good-tasting food influence body weight?, Physiol Behav. source

      Not checked in the free run.

    • cites [11] Johnson, 2014, Variety, palatability, and obesity, Adv Nutr. source

      Not checked in the free run.

    • cites [12] Stubbs, 2004, Energy density, diet composition and palatability: influences on overall food energy intake in humans, Physiol Behav. source

      Not checked in the free run.

  • Premisecitation

    No interventional studies in humans have demonstrated a causal relation between palatability and obesity, controlling for confounding factors such as macronutrient composition.

    “As reviewed by Johnson and Wardle (11), no interventional studies in humans have demonstrated a causal relation between palatability and obesity, controlling for confounding factors such as macronutrient composition.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [11] Johnson, 2014, Variety, palatability, and obesity, Adv Nutr. source

      Not checked in the free run.

  • Interpretationcitation

    Providing excess dietary energy to increase a man's weight from 75 kg to 90 kg would have elicited biological responses to resist that gain.

    “Providing excess dietary energy to increase his weight to 90 kg would have elicited biological responses (e.g., decreased hunger, increased energy expenditure) to resist that gain.”
    Quote in the paperSubstantial claim0 of 5 sources checked
    • cites [26] Apolzan, 2014, Effects of weight gain induced by controlled overfeeding on physical activity, Am J Physiol Endocrinol Metab. source

      Not checked in the free run.

    • cites [27] Norgan, 1980, The effect of 6 weeks of overfeeding on the body weight, body composition, and energy metabolism of young men, Am J Clin Nutr. source

      Not checked in the free run.

    • cites [28] Roberts, 1990, Energy expenditure and subsequent nutrient intakes in overfed young men, Am J Physiol.

      Not checked in the free run.

    • cites [29] Sims, 1968, Experimental obesity in man, Trans Assoc Am Physicians.

      Not checked in the free run.

    • cites [30] Leibel, 1995, Changes in energy expenditure resulting from altered body weight, N Engl J Med. source

      Not checked in the free run.

  • Classified as probably not a substantial claim. 20
  • May combine two claims. 30

  • Probably not a substantial claim: may not pass S2 (checkable), S4 (based).

    Findingreasoning

    None of these articles, nor recent dismissals of the CIM, provide a mechanistically oriented, testable model addressing dietary drivers of obesity, beyond the recurring focus on widely available, inexpensive, energy-dense, highly palatable, processed foods.

    “None of these articles, nor the recent dismissals of the CIM, provide a mechanistically oriented, testable model addressing dietary drivers of obesity, beyond the recurring focus on widely available, inexpensive, energy-dense, highly palatable, processed foods.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim. May combine two claims.

    Findingown data

    Supplemental Table 1 exemplifies the overwhelming dominance of energy balance in textbooks and professional society statements, and the importance of establishing a negative energy balance chiefly through decreased intake.

    “Supplemental Table 1 exemplifies the overwhelming dominance of energy balance in textbooks and professional society statements, and the importance of establishing a negative energy balance, chiefly through decreased intake.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim.

    Premisecitation

    The EBM considers all calories metabolically alike for practical purposes.

    “Importantly, the EBM considers all calories metabolically alike for practical purposes (7).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [7] Schwartz, 2017, Obesity pathogenesis: an Endocrine Society scientific statement, Endocr Rev. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationreasoning

    Statements regarding the importance of a negative energy balance provide no meaningful information about etiology because the relation between energy balance and weight change is inseverable.

    “Because the relation between energy balance and weight change is inseverable, statements regarding the importance of a negative balance provide no meaningful information about etiology.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Premisereasoning

    Weight gain (or fat gain) can occur only with a positive energy balance.

    “Weight gain (or more precisely, fat gain) can occur only with a positive energy balance, in the same way that a fever can occur only if the body generates more heat than it dissipates.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable), S4 (based).

    Interpretationnone given

    Conceptualizing obesity as a disorder of energy balance restates a principle of physics without considering the biological mechanisms that promote weight gain.

    “Conceptualizing obesity as a disorder of energy balance restates a principle of physics without considering the biological mechanisms that promote weight gain.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S4 (based).

    Interpretationnone given

    The carbohydrate-insulin model proposes a reversal of causal direction: increasing fat deposition resulting from hormonal responses to a high-glycemic-load diet drives positive energy balance.

    “According to the CIM, increasing fat deposition in the body—resulting from the hormonal responses to a high-glycemic-load diet—drives positive energy balance.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S4 (based).

    Interpretationnone given

    Among modifiable factors, dietary glycemic load has central importance.

    “Among modifiable factors, dietary glycemic load (GL) has central importance.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Patients with type 1 diabetes undergoing intensification of insulin therapy for 2 mo experienced a 2.4-kg increase in body fat, associated with decreased energy expenditure and therefore not fully attributable to changes in dietary intake and urinary glucose excretion.

    “Patients with type 1 diabetes undergoing intensification of insulin therapy for 2 mo experienced a 2.4-kg increase in body fat, associated with decreased energy expenditure and therefore not fully attributable to changes in dietary intake and urinary glucose excretion (70).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [70] Carlson, 1993, Intensive insulin therapy and weight gain in IDDM, Diabetes. source

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Interpretationcitation

    Greater insulin sensitivity in white adipose tissue relative to metabolically active or energy-sensing tissues will alter substrate partitioning in favor of fat deposition.

    “Greater insulin sensitivity in white adipose tissue relative to metabolically active or energy-sensing tissues will alter substrate partitioning in favor of fat deposition.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    Weight reduction produced by carbohydrate restriction would decrease the insulin-to-glucagon ratio, enhance lipolysis and fat oxidation, and result in lower spontaneous food intake.

    “In contrast, weight reduction produced by carbohydrate restriction would decrease the insulin-to-glucagon ratio, enhance lipolysis and fat oxidation, and result in lower spontaneous food intake.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    In humans, insulin and drugs that increase insulin secretion or adipose insulin sensitivity cause weight gain, whereas those that decrease insulin secretion cause weight loss.

    “In humans, insulin and drugs that increase insulin secretion or adipose insulin sensitivity cause weight gain, whereas those that decrease insulin secretion [including α-glucosidase inhibitors (68), which functionally lower the GI of starch] cause weight loss (69).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [69] Huang, 2020, Suppression of insulin secretion in the treatment of obesity: a systematic review and meta-analysis, Obesity. source

      Not checked in the free run.

  • May combine two claims.

    Interpretationreasoning

    Restricting energy intake when consuming a high-GL diet would neither lessen the predisposition to fat storage nor diminish hunger during dieting; rather, hunger would increase and energy expenditure may decline.

    “Restricting energy intake when consuming a high-GL diet would neither lessen the predisposition to fat storage nor diminish hunger during dieting. Rather, by further reducing metabolic fuel availability, hunger would increase and energy expenditure may decline.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationnone given

    Over the long term, a positive energy balance does not cause increasing adiposity; rather, a shift in substrate partitioning favoring fat storage drives a positive energy balance.

    “In other words, the CIM proposes a reversal of causal direction: over the long term, a positive energy balance does not cause increasing adiposity; rather, a shift in substrate partitioning favoring fat storage drives a positive energy balance, as shown in Figure 1.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    The rapid absorption of glucose after consumption of a high-GL meal increases insulin secretion, suppresses glucagon secretion, and elicits a GIP-dominant incretin response.

    “The rapid absorption of glucose after consumption of a high-GL meal increases insulin secretion, suppresses glucagon secretion, and elicits a glucose-dependent insulinotropic polypeptide (GIP)-dominant incretin response (35–37).”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites [35] Unger, 1971, Glucagon physiology and pathophysiology, N Engl J Med. source

      Not checked in the free run.

    • cites [36] Pfeiffer, 2018, High glycemic index metabolic damage – a pivotal role of GIP and GLP-1, Trends Endocrinol Metab. source

      Not checked in the free run.

    • cites [37] Runchey, 2013, Effect of low- and high-glycemic load on circulating incretins in a randomized clinical trial, Metabolism. source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Consumption of a high- compared with a low-GL meal results in reduced circulating metabolic fuel concentration after 3-5 h, associated with altered substrate partitioning, reduced energy expenditure, and a counter-regulatory response.

    “Consumption of a high- compared with a low-GL meal results in reduced circulating metabolic fuel concentration after 3–5 h (39–41, 79), associated with altered substrate partitioning, reduced energy expenditure, and a counter-regulatory response (31, 39, 41, 80, 81).”
    Quote in the paperSubstantial claim0 of 5 sources checked
    • cites [39] Ludwig, 1999, High glycemic index foods, overeating, and obesity, Pediatrics. source

      Not checked in the free run.

    • cites [40] Shimy, 2020, Effects of dietary carbohydrate content on circulating metabolic fuel availability in the postprandial state, J Endocr Soc. source

      Not checked in the free run.

    • cites [41] Walsh, 2013, Effects of diet composition on postprandial energy availability during weight loss maintenance, PLoS One. source

      Not checked in the free run.

    • cites [79] Chandler-Laney, 2014, Return of hunger following a relatively high carbohydrate breakfast is associated with earlier recorded glucose peak and nadir, Appetite. source

      Not checked in the free run.

    • cites [31] Ludwig, 2002, The glycemic index: physiological mechanisms relating to obesity, diabetes, and cardiovascular disease, JAMA. source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    GIP administration promotes preadipocyte differentiation and fat storage, and, in the brain, inflammation and insulin resistance.

    “GIP administration promotes preadipocyte differentiation and fat storage, and, in the brain, inflammation and insulin resistance.”
    Quote in the paperSubstantial claim0 of 5 sources checked
    • cites [36] Pfeiffer, 2018, High glycemic index metabolic damage – a pivotal role of GIP and GLP-1, Trends Endocrinol Metab. source

      Not checked in the free run.

    • cites [75] Irwin, 2020, Blockade of gastric inhibitory polypeptide (GIP) action as a novel means of countering insulin resistance in the treatment of obesity-diabetes, Peptides. source

      Not checked in the free run.

    • cites [76] Nauck, 2018, Incretin hormones: their role in health and disease, Diabetes Obes Metab. source

      Not checked in the free run.

    • cites [77] Fu, 2020, Gut hormone GIP induces inflammation and insulin resistance in the hypothalamus, Endocrinology. source

      Not checked in the free run.

    • cites [78] Boer, 2021, GIP receptor deletion in mice confers resistance to high-fat diet-induced obesity via alterations in energy expenditure and adipose tissue lipid metabolism, Am J Physiol Endocrinol Metab. source

      Not checked in the free run.

  • May combine two claims.

    Premisereasoning

    Simultaneously, hunger and cravings for high-GL foods increase, setting the stage for a vicious cycle.

    “Simultaneously, hunger and cravings for high-GL foods (i.e., those that rapidly raise blood glucose) increase, setting the stage for a vicious cycle.”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites [21] Mayer-Gross, 1946, Taste and selection of food in hypoglycaemia, Br J Exp Pathol.

      Not checked in the free run.

    • cites [22] Page, 2011, Circulating glucose levels modulate neural control of desire for high-calorie foods in humans, J Clin Invest. source

      Not checked in the free run.

    • cites [23] Strachan, 2004, Food cravings during acute hypoglycaemia in adults with type 1 diabetes, Physiol Behav. source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    In animals, high- compared with low-GI diets increase adiposity independently of energy intake, in association with lower physical activity level.

    “In animals, high- compared with low-GI diets increase adiposity independently of energy intake, in association with lower physical activity level (45, 93–96).”
    Quote in the paperSubstantial claim0 of 5 sources checked
    • cites [45] Scribner, 2008, Long-term effects of dietary glycemic index on adiposity, energy metabolism, and physical activity in mice, Am J Physiol Endocrinol Metab. source

      Not checked in the free run.

    • cites [93] Kabir, 1998, A high glycemic index starch diet affects lipid storage–related enzymes in normal and to a lesser extent in diabetic rats, J Nutr. source

      Not checked in the free run.

    • cites [94] Ludwig, 2020, Testing the carbohydrate-insulin model in mice: the importance of distinguishing primary hyperinsulinemia from insulin resistance and metabolic dysfunction, Mol Metab. source

      Not checked in the free run.

    • cites [95] Pawlak, 2001, High glycemic index starch promotes hypersecretion of insulin and higher body fat in rats without affecting insulin sensitivity, J Nutr. source

      Not checked in the free run.

    • cites [96] Pawlak, 2004, Effects of dietary glycaemic index on adiposity, glucose homoeostasis, and plasma lipids in animals, Lancet. source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    In rodents, chronic insulin treatment increases food intake and adiposity, and these effects are dissociable.

    “In rodents, chronic insulin treatment increases food intake and adiposity, and these effects are dissociable.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [65] Torbay, 1985, Insulin increases body fat despite control of food intake and physical activity, Am J Physiol.

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Factors of dubious relation to chronic energy balance, such as utensil size or plate color, influence acute consumption.

    “Myriad factors of dubious relation to chronic energy balance—such as utensil size (146) or plate color (147)—influence acute consumption.”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [146] James, 2018, Eating with a smaller spoon decreases bite size, eating rate and ad libitum food intake in healthy young males, Br J Nutr. source

      Not checked in the free run.

    • cites [147] Akyol, 2018, Impact of three different plate colours on short-term satiety and energy intake: a randomized controlled trial, Nutr J. source

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Premisenone given

    The chronic effect of GL on body composition in humans, with control for energy intake, has not been determined.

    “However, the chronic effect of GL on body composition in humans, with control for energy intake, has not been determined.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisenone given

    Circulating fuels are at best a proxy for substrate sensing and oxidation; these may be dissociated under certain conditions, such as insulin resistance or diabetes.

    “Moreover, circulating fuels are at best a proxy for substrate sensing and oxidation; these may be dissociated under certain conditions, such as insulin resistance or diabetes.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S2 (checkable), S4 (based). May combine two claims.

    Interpretationnone given

    Specific criticisms of the CIM are based on weak or misleading evidence, leading to misinterpretations.

    “However, specific criticisms are based on weak or misleading evidence, leading to the following misinterpretations.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Interpretationnone given

    The CIM posits a state akin to 'internal starvation'-an acceleration of fasting physiology emerging in the late postprandial period.

    “The CIM posits a state akin to “internal starvation”—an acceleration of fasting physiology emerging in the late postprandial period.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    In rodents, high saturated fat content causes hyperinsulinemia, liver and muscle insulin resistance, and hypothalamic inflammation.

    “which in rodents causes hyperinsulinemia, liver and muscle insulin resistance, and hypothalamic inflammation (137–143).”
    Quote in the paperSubstantial claim0 of 7 sources checked
    • cites [137] Milanski, 2009, Saturated fatty acids produce an inflammatory response predominantly through the activation of TLR4 signaling in hypothalamus: implications for the pathogenesis of obesity, J Neurosci. source

      Not checked in the free run.

    • cites [138] Benoit, 2009, Palmitic acid mediates hypothalamic insulin resistance by altering PKC-θ subcellular localization in rodents, J Clin Invest. source

      Not checked in the free run.

    • cites [139] Cintra, 2012, Unsaturated fatty acids revert diet-induced hypothalamic inflammation in obesity, PLoS One. source

      Not checked in the free run.

    • cites [140] Oliveira, 2015, Diets containing α-linolenic (ω3) or oleic (ω9) fatty acids rescues obese mice from insulin resistance, Endocrinology. source

      Not checked in the free run.

    • cites [141] Vijay-Kumar, 2011, Fish oil rich diet in comparison to saturated fat rich diet offered protection against lipopolysaccharide-induced inflammation and insulin resistance in mice, Nutr Metab (Lond). source

      Not checked in the free run.

    • cites [142] Dornellas, 2015, Deleterious effects of lard-enriched diet on tissues fatty acids composition and hypothalamic insulin actions, Prostaglandins Leukot Essent Fatty Acids. source

      Not checked in the free run.

    • cites [143] Davis, 2008, Tlr-4 deficiency selectively protects against obesity induced by diets high in saturated fat, Obesity. source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Obesity resulting from genetic disruption in leptin signaling is not necessarily mediated exclusively through hunger and energy intake; the ob/ob mouse has markedly increased adiposity even when energy-restricted to prevent excessive weight gain.

    “In one extensively studied example, obesity resulting from genetic disruption in leptin signaling is not necessarily mediated exclusively through hunger and energy intake; the ob/ob mouse has markedly increased adiposity even when energy-restricted to prevent excessive weight gain (136).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [136] Thurlby, 1979, The role of thermoregulatory thermogenesis in the development of obesity in genetically-obese (ob/ob) mice pair-fed with lean siblings, Br J Nutr. source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Changes in energy density influence food intake acutely, but this effect does not persist.

    “Changes in energy density influence food intake acutely (145), but this effect does not persist (17).”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [145] Bell, 2001, Energy density of foods affects energy intake across multiple levels of fat content in lean and obese women, Am J Clin Nutr. source

      Not checked in the free run.

    • cites [17] Saquib, 2007, The impact of a long-term reduction in dietary energy density on body weight within a randomized diet trial, Nutr Cancer. source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Low-carbohydrate diets have been reported to both cause and prevent adiposity in rodents.

    “Low-carbohydrate diets have been reported to both cause (97) and prevent (98) adiposity in rodents”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [97] Hu, 2020, The carbohydrate-insulin model does not explain the impact of varying dietary macronutrients on the body weight and adiposity of mice, Mol Metab. source

      Not checked in the free run.

    • cites [98] Kennedy, 2007, A high-fat, ketogenic diet induces a unique metabolic state in mice, Am J Physiol Endocrinol Metab. source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Substitution of unsaturated fat for saturated fat in these protocols, or ablation of toll-like receptor signaling, reduces metabolic dysfunction and adiposity in rodents.

    “Substitution of unsaturated fat for saturated fat in these protocols, or ablation of toll-like receptor signaling, reduces metabolic dysfunction and adiposity (137–143).”
    Quote in the paperSubstantial claim0 of 7 sources checked
    • cites [137] Milanski, 2009, Saturated fatty acids produce an inflammatory response predominantly through the activation of TLR4 signaling in hypothalamus: implications for the pathogenesis of obesity, J Neurosci. source

      Not checked in the free run.

    • cites [138] Benoit, 2009, Palmitic acid mediates hypothalamic insulin resistance by altering PKC-θ subcellular localization in rodents, J Clin Invest. source

      Not checked in the free run.

    • cites [139] Cintra, 2012, Unsaturated fatty acids revert diet-induced hypothalamic inflammation in obesity, PLoS One. source

      Not checked in the free run.

    • cites [140] Oliveira, 2015, Diets containing α-linolenic (ω3) or oleic (ω9) fatty acids rescues obese mice from insulin resistance, Endocrinology. source

      Not checked in the free run.

    • cites [141] Vijay-Kumar, 2011, Fish oil rich diet in comparison to saturated fat rich diet offered protection against lipopolysaccharide-induced inflammation and insulin resistance in mice, Nutr Metab (Lond). source

      Not checked in the free run.

    • cites [142] Dornellas, 2015, Deleterious effects of lard-enriched diet on tissues fatty acids composition and hypothalamic insulin actions, Prostaglandins Leukot Essent Fatty Acids. source

      Not checked in the free run.

    • cites [143] Davis, 2008, Tlr-4 deficiency selectively protects against obesity induced by diets high in saturated fat, Obesity. source

      Not checked in the free run.

  • May combine two claims.

    Premisenone given

    Reduced circulating fuel concentrations have been documented early in the development of experimental obesity and several hours after a high-GL meal in humans.

    “Reduced circulating fuel concentrations have been documented early in the development of experimental obesity and several hours after a high-GL meal in humans, as considered above.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Spontaneous physical activity is reduced during development of ventromedial hypothalamic obesity and increased fat deposition occurs even with restriction of food intake to that of controls.

    “Importantly, spontaneous physical activity is reduced during development of ventromedial hypothalamic obesity and increased fat deposition occurs even with restriction of food intake to that of controls.”
    Quote in the paperSubstantial claim0 of 7 sources checked
    • cites [42] Hetherington, 1942, The spontaneous activity and food intake of rats with hypothalamic lesions, Am J Physiol. source

      Not checked in the free run.

    • cites [48] Friedman, 1976, The physiological psychology of hunger: a physiological perspective, Psychol Rev. source

      Not checked in the free run.

    • cites [115] Bray, 1979, Hypothalamic and genetic obesity in experimental animals: an autonomic and endocrine hypothesis, Physiol Rev. source

      Not checked in the free run.

    • cites [116] Hustvedt, 1976, The effect of ventromedial hypothalamic lesions on metabolism and insulin secretion in rats on a controlled feeding regimen, Ann Nutr Metab. source

      Not checked in the free run.

    • cites [117] Karakash, 1977, Consequences of ventromedial hypothalamic lesions on metabolism of perfused rat liver, Am J Physiol.

      Not checked in the free run.

    • cites [118] Lovo, 1973, Correlation between altered acetate utilization and hyperphagia in rats with ventromedial hypothalamic lesions, Metabolism. source

      Not checked in the free run.

    • cites [119] Penicaud, 1989, Development of VMH obesity: in vivo insulin secretion and tissue insulin sensitivity, Am J Physiol.

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Immediately after injury to the ventromedial hypothalamus, hyperinsulinemia develops without systemic insulin resistance, and sympathetic nervous system tone is decreased.

    “Immediately after injury to the ventromedial hypothalamus, hyperinsulinemia develops without systemic insulin resistance, and sympathetic nervous system tone is decreased.”
    Quote in the paperSubstantial claim0 of 7 sources checked
    • cites [42] Hetherington, 1942, The spontaneous activity and food intake of rats with hypothalamic lesions, Am J Physiol. source

      Not checked in the free run.

    • cites [48] Friedman, 1976, The physiological psychology of hunger: a physiological perspective, Psychol Rev. source

      Not checked in the free run.

    • cites [115] Bray, 1979, Hypothalamic and genetic obesity in experimental animals: an autonomic and endocrine hypothesis, Physiol Rev. source

      Not checked in the free run.

    • cites [116] Hustvedt, 1976, The effect of ventromedial hypothalamic lesions on metabolism and insulin secretion in rats on a controlled feeding regimen, Ann Nutr Metab. source

      Not checked in the free run.

    • cites [117] Karakash, 1977, Consequences of ventromedial hypothalamic lesions on metabolism of perfused rat liver, Am J Physiol.

      Not checked in the free run.

    • cites [118] Lovo, 1973, Correlation between altered acetate utilization and hyperphagia in rats with ventromedial hypothalamic lesions, Metabolism. source

      Not checked in the free run.

    • cites [119] Penicaud, 1989, Development of VMH obesity: in vivo insulin secretion and tissue insulin sensitivity, Am J Physiol.

      Not checked in the free run.

  • May combine two claims.

    Premisenone given

    In DIETFITS, the low-fat diet included a focus on reducing refined carbohydrates, and both GI and GL decreased in this diet group.

    “Of note, the low-fat diet included a focus on reducing refined carbohydrates, and both GI and GL decreased in this diet group.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    By reducing anabolic drive with a low-GL diet, patients may experience less hunger and improved energy level, promoting spontaneous weight loss.

    “By reducing anabolic drive with a low-GL diet, patients may experience less hunger and improved energy level, promoting spontaneous weight loss in the same way that an antipyretic reduces fever without conscious control of heat balance.”
    Quote in the paperNot a substantial claim
    • Rests on an assumption: Predictable biological responses oppose weight loss, including decreased metabolic rate and elevated hunger.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationcitation

    For the CIM, a clear distinction, implicit in iterations dating back a century, entails reversal of the causal pathway linking diet, and specifically carbohydrates, to weight gain.

    “For the CIM, a clear distinction, implicit in iterations dating back a century (Table 1), entails reversal of the causal pathway linking diet, and specifically carbohydrates, to weight gain.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Table 1

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    In DIETFITS, weight loss was greater when consuming a low-carbohydrate than low-fat diet at 3 and 6 months, a difference that did not persist at 12 months.

    “In DIETFITS (Diet Intervention Examining The Factors Interacting with Treatment Success), weight loss was greater when consuming a low-carbohydrate than when consuming a low-fat diet at 3 and 6 mo, a difference that did not persist at 12 mo (156, 157).”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [156] Gardner, 2018, Effect of low-fat vs low-carbohydrate diet on 12-month weight loss in overweight adults and the association with genotype pattern or insulin secretion: the DIETFITS randomized clinical trial, JAMA. source

      Not checked in the free run.

    • cites [157] Guo, 2019, Objective versus self-reported energy intake changes during low-carbohydrate and low-fat diets, Obesity. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S4 (based).

    Interpretationnone given

    An overestimation of energy requirements by 300 kcal/d would produce rapid weight gain.

    “An overestimation of this magnitude would produce rapid weight gain.”
    Quote in the paperNot a substantial claim
    • Rests on an assumption: Outside the research laboratory, there is no feasible way to measure individual energy requirements to a precision within 300 kcal/d.

  • May combine two claims.

    Premisecitation

    The actions of carbohydrate on metabolism persist well beyond the postprandial state, as demonstrated by the second meal effect and the effect of a low-carbohydrate diet on fasting insulin.

    “the actions of carbohydrate on metabolism persist well beyond the postprandial state, as demonstrated by the “second meal effect,” wherein the GI of supper influences glucose tolerance the next day (161, 162), and by the effect of a low-carbohydrate diet on fasting insulin (163).”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites [161] Axelsen, 1999, Breakfast glycaemic response in patients with type 2 diabetes: effects of bedtime dietary carbohydrates, Eur J Clin Nutr. source

      Not checked in the free run.

    • cites [162] Wolever, 1988, Second-meal effect: low-glycemic-index foods eaten at dinner improve subsequent breakfast glycemic response, Am J Clin Nutr. source

      Not checked in the free run.

    • cites [163] Grey, 1971, Effect of diet composition on the hyperinsulinemia of obesity, N Engl J Med. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing). May combine two claims.

    Interpretationnone given

    The iteration of the CIM presented here cannot provide a complete and precise representation of all causal mechanisms; nor does it preclude the existence of other causative influences.

    “the iteration of the CIM presented here cannot provide a complete and precise representation of all causal mechanisms; nor does it preclude the existence of other causative influences.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

    Interpretationnone given

    Hardwired hedonic preferences for sweetness may drive consumption of sugary foods, which in turn may also affect substrate partitioning through calorie-independent mechanisms.

    “hardwired hedonic preferences for sweetness may drive consumption of sugary foods (consistent with the EBM), which in turn may also affect substrate partitioning through calorie-independent mechanisms (consistent with the CIM).”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing).

    Interpretationreasoning

    Translation of the EBM to public health may be especially problematic.

    “Translation of the EBM to public health may be especially problematic.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing).

    Interpretationreasoning

    For practical purposes, people must determine their dietary energy allowance empirically, as the amount with which body weight remains stable.

    “For practical purposes, people must determine their dietary energy allowance empirically, as the amount with which body weight remains stable—yet another tautology.”
    Quote in the paperNot a substantial claim
    • Rests on an assumption: Outside the research laboratory, there is no feasible way to measure individual energy requirements to a precision within 300 kcal/d.

  • May combine two claims.

    Premisecitation

    In a recent meta-analysis, low- compared with high-carbohydrate diets slightly reduced energy expenditure in trials <2.5 weeks, but low-carbohydrate diets increased energy expenditure in longer trials.

    “In a recent meta-analysis, low- compared with high-carbohydrate diets slightly reduced energy expenditure in trials < 2.5 wk, but low-carbohydrate diets increased energy expenditure in longer trials (100).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [100] Ludwig, 2021, Do lower-carbohydrate diets increase total energy expenditure? An updated and reanalyzed meta-analysis of 29 controlled-feeding studies, J Nutr. source

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Interpretationreasoning

    Conventional notions of palatability and the metabolic effects of preferred foods would work in concert to drive fat accumulation.

    “In this sense, conventional notions of palatability and the metabolic effects of preferred foods would work in concert to drive fat accumulation.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    In Pounds Lost, participants reported little difference in macronutrient intakes at 2 years and biomeasures of adherence showed little differentiation between dietary groups.

    “In the Pounds Lost (Preventing Obesity Using Novel Dietary Strategies) study (155), participants reported little difference in macronutrient intakes at 2 y and biomeasures of adherence (serum triglycerides, urinary nitrogen excretion) showed little differentiation between dietary groups.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [155] Sacks, 2009, Comparison of weight-loss diets with different compositions of fat, protein, and carbohydrates, N Engl J Med. source

      Not checked in the free run.

46 of 46

  • The paper relies on this without support.

    Obesity prevalence remains high and continues to increase worldwide despite public health focus on energy restriction and exercise.

    “Nevertheless, obesity prevalence continues to increase worldwide, prompting spectacularly complex formulations of the EBM addressing myriad biological, behavioral, environmental, and societal factors converging on energy balance (Supplemental Figure 1), with questionable practical translation.”

  • The paper relies on this without support.

    The energy balance model is the dominant model for obesity.

    “In the dominant energy balance model (EBM), energy-dense, tasty, modern processed foods drive a positive energy balance through increased intake, and thereby result in fat deposition.”

  • The paper relies on this without support.

    Low-carbohydrate diets have high energy density due to their high fat content.

    “Low-carbohydrate diets have high energy density due to their high fat content.”

  • The paper relies on this without support.

    Most diet trials have used low-intensity interventions to promote behavioral change.

    “Most diet trials have used low-intensity interventions to promote behavioral change.”

  • The paper relies on this without support.

    Most participants in diet trials have difficulty sustaining dietary change.

    “Most participants in these studies have difficulty sustaining dietary change, limiting inferences about efficacy.”

  • The paper relies on this without support.

    With initiation of a very-low-carbohydrate diet, ketones rise, providing an alternative fuel to the brain, thereby preserving lean mass.

    “With initiation of a very-low-carbohydrate diet, ketones rise, providing an alternative fuel to the brain, thereby preserving lean mass.”

  • The paper relies on this without support.

    Insulin is a multifunctional hormone, secreted in response to numerous dietary and nondietary factors.

    “Clearly, insulin is a multifunctional hormone, secreted in response to numerous dietary and nondietary factors.”

  • The paper relies on this without support.

    The average increase in body weight throughout the last half century is attributable to the storage of less than 1 g extra fat per day.

    “The average increase in body weight throughout the last half century is attributable to the storage of <1 g extra fat per day, illustrating the difficulty in exploring causal mechanisms with short-term studies.”

  • The paper relies on this without support.

    Calorie restriction for obesity treatment results in weight loss initially.

    “Calorie restriction for obesity treatment results in weight loss—initially—giving patients the impression they have conscious control over their body weight.”

  • The paper relies on this without support.

    Predictable biological responses oppose weight loss, including decreased metabolic rate and elevated hunger.

    “But predictable biological responses oppose weight loss, including decreased metabolic rate and elevated hunger.”

  • The paper relies on this without support.

    Few people achieve clinically significant weight loss over the long term with calorie restriction.

    “Few people achieve clinically significant weight loss over the long term with this approach.”

  • The paper relies on this without support.

    Outside the research laboratory, there is no feasible way to measure individual energy requirements to a precision within 300 kcal/d.

    “Outside the research laboratory, there is no feasible way to measure individual energy requirements to a precision within 300 kcal/d.”

  • The paper relies on this without support.

    The diets of subsistence farming societies were historically based on inexpensive, high-carbohydrate grains and tubers without the metabolic consequences suggested by the CIM.

    “The diets of subsistence farming societies were historically based on inexpensive, high-carbohydrate grains and tubers without the metabolic consequences suggested by the CIM.”

  • The paper relies on this without support.

    Many dietary and nondietary factors undoubtedly contribute to obesity trends.

    “In any event, many dietary and nondietary factors undoubtedly contribute to these trends.”
14 of 14

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?

  • Multiple lines of evidence support the maladaptive response of human populations to rapidly changing nutritional, physical, psychological and cultural environments in the modern world.

    “Multiple lines of evidence support the maladaptive response of human populations to rapidly changing nutritional, physical, psychological and cultural environments, in the modern world [5,11,14,75].”

    From Polycystic Ovary Syndrome: An Evolutionary Adaptation to Lifestyle and the Environment (2022) · cites this paper as [75]

    The Introduction (page unavailable) links the rapid worldwide rise in BMI to changing environmental conditions, and the discussion of the nutrition transition describes dietary change alongside possible effects of physical activity. The paper supports the nutritional and physical aspects of the claim, but the passages do not establish a maladaptive response to rapidly changing psychological and cultural environments. (LLM, conf=0.82)

    Experimental — accuracy not yet measured

  • A lower fiber, high-GI food like white crystalline sugar causes a rapid spike in blood glucose, leading to a quick insulin response that promotes lipogenesis and often stimulates hunger soon after.

    “In contrast, a lower fiber, high-GI food like white crystalline sugar causes a rapid spike in blood glucose, leading to a quick insulin response that promotes lipogenesis and often stimulates hunger soon after [2].”

    From Beyond Calories: Individual Metabolic and Hormonal Adaptations Driving Variability in Weight Management—A State-of-the-Art Narrative Review (2024) · cites this paper as [2]

  • The "calories in, calories out" model assumes that caloric expenditure and intake are accurately measurable and linearly related to weight loss.

    “The “calories in, calories out” model, also known as the dominant energy balance model, assumes that caloric expenditure and intake are accurately measurable and linearly related to weight loss [2].”

    From Beyond Calories: Individual Metabolic and Hormonal Adaptations Driving Variability in Weight Management—A State-of-the-Art Narrative Review (2024) · cites this paper as [2]

Cites

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Related

Authors
Ludwig, D. S., Aronne, L. J., Astrup, A., de Cabo, R., Cantley, L. C., Friedman, M. I., Heymsfield, S. B., Johnson, J. D., King, J. C., Krauss, R. M., Lieberman, D. E., Taubes, G., Volek, J. S., Westman, E. C., Willett, W. C., Yancy, Jr., & Ebbeling, C. B.
Affiliations
  • Boston Children's Hospital (US)
  • Weill Cornell Medicine (US)
  • University of Copenhagen (DK)
  • Monell Chemical Senses Center (US)
  • Pennington Biomedical Research Center (US)
  • University of British Columbia (CA)
  • University of California, Berkeley (US)
  • University of California, San Francisco (US)
  • Harvard University (US)
  • The Ohio State University (US)
  • Duke University (US)
  • Brigham and Women's Hospital (US)
Corresponding author
Ludwig, David S
ORCID
Venue
The American Journal of Clinical Nutrition
Publisher
Elsevier BV
Published
2021-12
Volume
114
Issue
6
Pages
1873-1885
ISSN
0002-9165 (ISSN-L)
DOI
10.1093/ajcn/nqab270
PMC
PMC8634575
OpenAlex
W3200181038
Semantic Scholar
3295ae6f1590fc89624cb8f306aa8edeecdc71f6
Cited by
292
References
168
Citations by year
2026: 44 · 2025: 46 · 2024: 52 · 2023: 62 · 2022: 78 · 2021: 9
FWCI
26.36
Type
journal article
Language
en
Open access
Licence
Locations
  • American Journal of Clinical Nutrition (publishedVersion, cc-by-nc)
  • PubMed Central (publishedVersion, cc-by-nc)
  • PubMed (publishedVersion)
  • Research at the University of Copenhagen (University of Copenhagen) (publishedVersion, cc-by-nc)
  • eScholarship (California Digital Library) (submittedVersion, cc-by-nc)
Funders
  • Eli Lilly and Company
  • Pfizer
  • Sanofi
  • Zafgen
  • UnitedHealth Group
  • Novo Nordisk
  • National Institutes of Health
  • Canadian Institutes of Health Research
  • National Cancer Institute (R35CA197588)
  • National Institute of Diabetes and Digestive and Kidney Diseases (P30DK072476)
Topics
  • Life Sciences › Neuroscience › Endocrine and Autonomic Systems › Regulation of Appetite and Obesity
  • Health Sciences › Medicine › Endocrinology, Diabetes and Metabolism › Diet, Metabolism, and Disease
  • Health Sciences › Medicine › Public Health, Environmental and Occupational Health › Obesity, Physical Activity, Diet
Keywords
obesity, energy balance model, energy balance, fat deposition, glycemic load, insulin, obesity treatment, sedentary lifestyle, processed foods
MeSH terms
Energy Intake, Carbohydrates, Dietary Carbohydrates, Dietary Fats, Energy Metabolism, Humans, Insulin, Obesity, Pandemics

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.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-06.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-06.

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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