History of modern nutrition science—implications for current research, dietary guidelines, and food policy

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The first vitamin was isolated and chemically defined in 1926.

“The first vitamin was isolated and chemically defined in 1926, less than 100 years ago”

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In 1932, vitamin C was isolated and definitively documented, for the first time, to protect against scurvy.

“In 1932, vitamin C was isolated and definitively documented, for the first time, to protect against scurvy,6 some 200 years after ship’s surgeon James Lind tested lemons for treating scurvy in sailors.7”

• cites [6] American Chemical Society National Historic Chemical Landmarks. The Discovery of Vitamin C by Albert Szent-Györgyi. 2002. https://www.acs.org/content/acs/en/education/whatischemistry/landmarks/szentgyorgyi.htmlNot checked yet

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• cites [7] Lind J A Treatise of the scurvy. A Millar, 1753.Not checked yet

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Identification of vitamins in animal and human studies proved the nutritional basis of serious deficiency diseases and initially led to dietary strategies to tackle beriberi, pellagra, scurvy, pernicious anaemia, rickets, and other deficiency conditions.

“Their identification in animal and human studies proved the nutritional basis of serious deficiency diseases and initially led to dietary strategies to tackle beriberi (vitamin B1), pellagra (vitamin B3), scurvy (vitamin C), pernicious anaemia (vitamin B12), rickets (vitamin D), and other deficiency conditions.”

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Casimir Funk in 1913 proposed the idea of a 'vital amine' in food, originating from the observation that the hulk of unprocessed rice protected chickens against a beriberi-like condition.

“Casimir Funk in 1913 came up with idea of a “vital amine” in food, originating from the observation that the hulk of unprocessed rice protected chickens against a beriberi-like condition.5”

• cites [5] Eijkman C. Nobel Lecture: the Nobel Prize in Physiology or Medicine. 1929. https://www.nobelprize.org/nobel_prizes/medicine/laureates/1929/eijkman-lecture.html.Not checked yet

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Key historical events in modern nutrition science form the basis of current understanding of diet and health and clarify contemporary priorities, new trends, and controversies in nutrition science and policy.

“This article describes key historical events in modern nutrition science that form the basis of our current understanding of diet and health and clarify contemporary priorities, new trends, and controversies in nutrition science and policy.”

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By the mid-20th century all major vitamins had been isolated and synthesised.

“By the mid-20th century all major vitamins had been isolated and synthesised (fig 1).”

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The first half of the 20th century witnessed the identification and synthesis of many known essential vitamins and minerals and their use to prevent and treat nutritional deficiency related diseases including scurvy, beriberi, pellagra, rickets, xerophthalmia, and nutritional anaemias.

“The first half of the 20th century witnessed the identification and synthesis of many of the known essential vitamins and minerals and their use to prevent and treat nutritional deficiency related diseases including scurvy, beriberi, pellagra, rickets, xerophthalmia, and nutritional anaemias.”

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The first recommended dietary allowances (RDAs) were a direct result of concerns about food shortages during the Great Depression and second world war, when the League of Nations, British Medical Association, and the US government separately commissioned scientists to generate new minimum dietary requirements to be prepared for war.

“For example, the first recommended dietary allowances (RDAs) were a direct result of these concerns, when the League of Nations, British Medical Association, and the US government separately commissioned scientists to generate new minimum dietary requirements to be prepared for war.14”

• cites [14] Harper AE Evolution of recommended dietary allowances–new directions? Annu Rev Nutr 1987; 7: 509- 37. 10.1146/annurev.nu.07.070187.002453 3300745Not checked yet

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The 'vital amine' or vitamin was first isolated in 1926 and named thiamine, and subsequently synthesised in 1936 as vitamin B1.

“This “vital amine” or vitamin was first isolated in 1926 and named thiamine, and subsequently synthesised in 1936 as vitamin B1.”

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Research on the role of nutrition in complex non-communicable chronic diseases accelerated over the past two or three decades and especially after 2000.

“Research on the role of nutrition in complex non-communicable chronic diseases, such as cardiovascular disease, diabetes, obesity, and cancers, is even more recent, accelerating over the past two or three decades and especially after 2000.”

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Accelerating economic development and modernisation of agricultural, food processing, and food formulation techniques continued to reduce single nutrient deficiency diseases globally.

“Accelerating economic development and modernisation of agricultural, food processing, and food formulation techniques continued to reduce single nutrient deficiency diseases globally.”

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Among the most important scientific developments of recent decades was the design and completion of multiple, complementary, large nutrition studies, including prospective observational cohorts, randomised clinical trials, and, more recently, genetic consortiums.

“Among the most important scientific development of recent decades was the design and completion of multiple, complementary, large nutrition studies, including prospective observational cohorts, randomised clinical trials, and, more recently, genetic consortiums.”

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Field trials provided a basis for WHO recommendations for widespread micronutrient supplementation, especially during pregnancy, with iron and vitamin A, and for fortification of salt with iodine to prevent goitre and developmental abnormalities such as congenital hypothyroidism and hearing loss.

“Field trials provided a basis for WHO recommendations for widespread micronutrient supplementation, especially during pregnancy, with iron and vitamin A, and for fortification of salt with iodine to prevent goitre and developmental abnormalities such as congenital hypothyroidism and hearing loss.”

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For weight loss and glycaemic control, decades of emphasis on low fat diets were questioned by the results of a series of prospective cohort studies, metabolic feeding studies, and randomised trials, which showed that foods rich in healthy fats produced benefit, while foods rich in starch and sugar caused harm.

“For weight loss and glycaemic control, decades of emphasis on low fat diets were questioned by the results of a series of prospective cohort studies, metabolic feeding studies, and randomised trials, which showed that foods rich in healthy fats produced benefit, while foods rich in starch and sugar caused harm.33 45 46 47”

• cites [33] Mozaffarian D Dietary and policy priorities for cardiovascular disease, diabetes, and obesity: a comprehensive review. Circulation 2016; 133: 187- 225. 10.1161/CIRCULATIONAHA.115.018585 26746178 PMC4814348Not checked yet

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• cites [45] Mensink RP Zock PL Kester AD Katan MB Effects of dietary fatty acids and carbohydrates on the ratio of serum total to HDL cholesterol and on serum lipids and apolipoproteins: a meta-analysis of 60 controlled trials. Am J Clin Nutr 2003; 77: 1146- 55. 10.1093/ajcn/77.5.1146 12716665Not checked yet

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• cites [46] Tobias DK Chen M Manson JE Ludwig DS Willett W Hu FB Effect of low-fat diet interventions versus other diet interventions on long-term weight change in adults: a systematic review and meta-analysis. Lancet Diabetes Endocrinol 2015; 3: 968- 79. 10.1016/S2213-8587(15)00367-8 26527511 PMC4667723Not checked yet

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This led to a proliferation of industrially crafted food products low in fat, saturated fat, and cholesterol and fortified with micronutrients, as well as expansion of other nutrient focused technologies to reduce saturated fat such as partial hydrogenation of vegetable oils.

“This led to a proliferation of industrially crafted food products low in fat, saturated fat, and cholesterol and fortified with micronutrients, as well as expansion of other nutrient focused technologies to reduce saturated fat such as partial hydrogenation of vegetable oils.”

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Ultimately, the emphasis on fat won scientific and policy acceptance, embodied in the 1977 US Senate committee report Dietary Goals for the United States, which recommended low fat, low cholesterol diets for all.

“Ultimately, the emphasis on fat won scientific and policy acceptance, embodied in the 1977 US Senate committee report Dietary Goals for the United States, which recommended low fat, low cholesterol diets for all.”

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At the same time, the rising burdens of diet related non-communicable diseases began to be recognised, leading to new research directions.

“At the same time, the rising burdens of diet related non-communicable diseases began to be recognised, leading to new research directions.”

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Evidence was increasing that vitamin A supplements could prevent child mortality from infection, such as measles, as well as preventing night blindness and xerophthalmia.

“Evidence was increasing that vitamin A supplements could prevent child mortality from infection, such as measles, as well as preventing night blindness and xerophthalmia.26”

• cites [26] Sommer A West KPJ Vitamin A deficiency: health, survival, and vision. Oxford University Press, 1996.Not checked yet

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Coronary mortality began to fall in high income countries, but many other diet related chronic diseases were increasing, including obesity, type 2 diabetes, and several cancers.

“Coronary mortality also began to fall in high income countries, but many other diet related chronic diseases were increasing, including obesity, type 2 diabetes, and several cancers.”

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Clinical trials allowed further testing of specific questions in targeted, often high risk populations, in particular effects of isolated vitamin supplements and, more recently, specific diet patterns.

“Clinical trials allowed further testing of specific questions in targeted, often high risk populations, in particular effects of isolated vitamin supplements and, more recently, specific diet patterns.”

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Genetic consortiums provided important evidence on genetic influences on dietary choices, gene-diet interactions affecting disease risk factors and endpoints, and Mendelian randomisation studies of causal effects of nutritional biomarkers.

“Genetic consortiums provided important evidence on genetic influences on dietary choices, gene-diet interactions affecting disease risk factors and endpoints, and Mendelian randomisation studies of causal effects of nutritional biomarkers.”

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Despite the shift in scientific thinking to focus on economic development, substantial emphasis remained or even accelerated on providing sufficient calories, most often as starchy staples, plus vitamin fortification and supplementation.

“Thus, despite the shift in scientific thinking to focus on economic development, substantial emphasis remained or even accelerated on providing sufficient calories, most often as starchy staples, plus vitamin fortification and supplementation.”

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In contrast to single nutrients, physiological intervention trials, large cohort studies, and randomised clinical trials provided more consistent evidence for diet patterns, such as low fat diets (few significant effects) or Mediterranean and similar food based patterns (consistent benefits).

“In contrast to single nutrients, physiological intervention trials, large cohort studies, and randomised clinical trials provided more consistent evidence for diet patterns, such as low fat diets (few significant effects) or Mediterranean and similar food based patterns (consistent benefits).32 33”

• cites [32] Dietary Guidelines Advisory Committee Scientific Report of the 2015 Dietary Guidelines Advisory Committee 2015. http://www.health.gov/dietaryguidelines/2015-scientific-report/Not checked yet

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• cites [33] Mozaffarian D Dietary and policy priorities for cardiovascular disease, diabetes, and obesity: a comprehensive review. Circulation 2016; 133: 187- 225. 10.1161/CIRCULATIONAHA.115.018585 26746178 PMC4814348Not checked yet

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Nutrient supplementation strategies remained effective at preventing or treating endemic deficiency diseases.

“In addition, nutrient supplementation strategies remained effective at preventing or treating endemic deficiency diseases.”

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These studies followed the deficiency disease model, largely considering isolated single nutrients.

“More importantly, these studies followed the deficiency disease model, largely considering isolated single nutrients.”

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During the next 20 to 30 years, calorie malnutrition and specific vitamin deficiencies fell sharply in high income countries because of economic development and large increases in low cost processing of staple foods fortified with minerals and vitamins.

“During the next 20 to 30 years, calorie malnutrition and specific vitamin deficiencies fell sharply in high income countries because of economic development and large increases in low cost processing of staple foods fortified with minerals and vitamins.”

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Work by John Yudkin and others implicated excess sugar in coronary disease, hypertriglyceridemia, cancer, and dental caries.

“At the same time, work by John Yudkin and others implicated excess sugar in coronary disease, hypertriglyceridemia, cancer, and dental caries.”

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Cohort studies provided, for the first time, individual level, multivariable adjusted findings on a range of nutrients, foods, and diet patterns and a diversity of health outcomes.

“Cohort studies provided, for the first time, individual level, multivariable adjusted findings on a range of nutrients, foods, and diet patterns and a diversity of health outcomes.”

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Modern nutrition science is young: less than one century has passed since the first vitamin was isolated in 1926.

“Modern nutrition science is young: It is less than one century since the first vitamin was isolated in 1926”

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After decades of focus on simple, reductionist metrics such as dietary fat, saturated fat, nutrient density, and energy density, the emerging true complexities of different foods and diet patterns create genuine challenges for understanding influences on health and wellbeing.

“After decades of focus on simple, reductionist metrics such as dietary fat, saturated fat, nutrient density, and energy density, the emerging true complexities of different foods and diet patterns create genuine challenges for understanding influences on health and wellbeing.”

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Recognition of complexity is a key lesson of the past.

“Recognition of complexity is a key lesson of the past.”

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This inertia is seen in the reductionist, single nutrient focus of many of the UN sustainable development goals.

“This is seen, for example, in the reductionist, single nutrient focus of many of the UN sustainable development goals.”

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In scientific progress, initial observations lead to simplified theories that achieve practical benefits, which are then advanced by new knowledge and recognition of increasing complexity.

“This is common in scientific progress whether in nutrition, clinical medicine, physics, political science, or economics: initial observations lead to reasonable, simplified theories that achieve certain practical benefits, which are then inevitably advanced by new knowledge and recognition of ever-increasing complexity.35”

• cites [35] Mozaffarian D Forouhi NG Dietary guidelines and health—is nutrition science up to the task? BMJ 2018; 360: k822. 10.1136/bmj.k822 29549076Not checked yet

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Even when non-communicable diseases are considered, the predominant focus is on obesity rather than the diverse risk pathways and conditions affected by nutrition-facilitating a misleading concept of 'overnutrition' rather than unhealthy dietary composition as the root problem.

“Even when non-communicable diseases are considered, the predominant focus is on obesity rather than the diverse risk pathways and conditions affected by nutrition—facilitating a misleading concept of “overnutrition” rather than unhealthy dietary composition as the root problem.55”

• cites [55] Min J Zhao Y Slivka L Wang Y Double burden of diseases worldwide: coexistence of undernutrition and overnutrition-related non-communicable chronic diseases. Obes Rev 2018; 19: 49- 61. 10.1111/obr.12605 28940822 PMC5962023Not checked yet

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Relatively little rigorous evaluation has been done on potential long term health consequences of modern shifts in agricultural practices, livestock feeding, crop breeding, and food processing methods such as grain milling and processing; plant oil extraction, deodorisation, and interesterification; dairy fat homogenisation; and use of emulsifiers and thickeners.

“Relatively little rigorous evaluation has been done on potential long term health consequences of modern shifts in agricultural practices, livestock feeding, crop breeding, and food processing methods such as grain milling and processing; plant oil extraction, deodorisation, and interesterification; dairy fat homogenisation; and use of emulsifiers and thickeners.”

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Knowledge alone has relatively limited effects on behaviour, and broader systems, policy, and environmental strategies are needed for effective change.

“However, it is now clear that knowledge alone has relatively limited effects on behaviour, and that broader systems, policy, and environmental strategies are needed for effective change.66 67”

• cites [66] Afshin A Micha R Khatibzadeh S Dietary policies to reduce non-communicable diseases. In: Brown GW Yamey G Wamala S, eds. The handbook of global health policy. 1st ed John Wiley & Sons, Ltd, 2014. 10.1002/9781118509623.ch9Not checked yet

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• cites [67] Mozaffarian D Afshin A Benowitz NL American Heart Association Council on Epidemiology and Prevention, Council on Nutrition, Physical Activity and Metabolism, Council on Clinical Cardiology, Council on Cardiovascular Disease in the Young, Council on the Kidney in Cardiovasc Population approaches to improve diet, physical activity, and smoking habits: a scientific statement from the American Heart Association. Circulation 2012; 126: 1514- 63. 10.1161/CIR.0b013e318260a20b 22907934 PMC3881293Not checked yet

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The first half of the 20th century focused on the discovery, isolation, and synthesis of essential micronutrients and their role in deficiency diseases.

“The first half of the 20th century focused on the discovery, isolation, and synthesis of essential micronutrients and their role in deficiency diseases”

May combine two claims.

A precipitous rise in non-communicable diseases in lower income countries has led to new focus on the 'double burden'-both conventionally conceived malnutrition (insufficient calories and micronutrients) leading to poor maternal and child health and modern malnutrition (poor diet quality) leading to obesity, type 2 diabetes, cardiovascular diseases, and cancer.

“In addition, a precipitous rise in non-communicable diseases in these countries has led to new focus on the “double burden”—both conventionally conceived malnutrition (insufficient calories and micronutrients) leading to poor maternal and child health and modern malnutrition (poor diet quality) leading to obesity, type 2 diabetes, cardiovascular diseases, and cancer.”

• cites [53] Black RE Victora CG Walker SP Maternal and Child Nutrition Study Group Maternal and child undernutrition and overweight in low-income and middle-income countries. Lancet 2013; 382: 427- 51. 10.1016/S0140-6736(13)60937-X 23746772Not checked yet

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• cites [54] Kosaka S Umezaki M A systematic review of the prevalence and predictors of the double burden of malnutrition within households. Br J Nutr 2017; 117: 1118- 27. 10.1017/S0007114517000812 28514987Not checked yet

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• cites [55] Min J Zhao Y Slivka L Wang Y Double burden of diseases worldwide: coexistence of undernutrition and overnutrition-related non-communicable chronic diseases. Obes Rev 2018; 19: 49- 61. 10.1111/obr.12605 28940822 PMC5962023Not checked yet

  Not checked in the free run.

May combine two claims.

In lower income countries, concerns about vitamin supplementation have emerged, such as harms associated with higher dose vitamin A supplements, risk of exacerbating infections such as malaria with iron, and safety concerns about folic acid fortification of flour, which might exacerbate neurological and cognitive deficits among people with low vitamin B12 levels.

“In lower income countries, concerns about vitamin supplementation have emerged, such as harms associated with higher dose vitamin A supplements, risk of exacerbating infections such as malaria with iron, and safety concerns about folic acid fortification of flour, which might exacerbate neurological and cognitive deficits among people with low vitamin B12 levels.49 50 51 52”

• cites [49] Crider KS Bailey LB Berry RJ Folic acid food fortification—its history, effect, concerns, and future directions. Nutrients 2011; 3: 370- 84. 10.3390/nu3030370 22254102 PMC3257747Not checked yet

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• cites [50] Castillo-Lancellotti C Tur JA Uauy R Impact of folic acid fortification of flour on neural tube defects: a systematic review. Public Health Nutr 2013; 16: 901- 11. 10.1017/S1368980012003576 22850218 PMC10271422Not checked yet

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• cites [51] Fawzi WW The benefits and concerns related to vitamin a supplementation. J Infect Dis 2006; 193: 756- 9. 10.1086/500369 16479507Not checked yet

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Over months to years, some foods may impair pathways of weight homeostasis, others may have neutral effects, and others may promote integrity of weight regulation.

“Over months to years, some foods may impair pathways of weight homeostasis, others may have relatively neutral effects, and others may promote integrity of weight regulation.”

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Lower income countries are recognising a growing double burden of combined undernutrition and non-communicable disease.

“●Lower income countries are recognising a growing “double burden” (combined undernutrition and non-communicable disease)”

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These long-term effects will be especially relevant as anti-obesity efforts shift from secondary prevention (weight loss in people with obesity) to primary prevention (avoidance of long-term weight gain in populations).

“These long term effects will be especially relevant as anti-obesity efforts shift from secondary prevention (weight loss in people with obesity) towards primary prevention (avoidance of long term weight gain in populations).”

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Although reductionist policies may have some value for reducing specific additives (e.g., trans fats, sodium, added sugar), whole food based policies will be crucial to fully address diet related illnesses.

“Although reductionist policies may have some value to reduce specific additives—eg, trans fats, sodium, added sugar—whole food based policies will be crucial to fully address diet related illnesses.”

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

Recent advances in nutrition science have shown that foods and diet patterns, rather than nutrient-focused metrics, explain many effects of diet on non-communicable disease.

“Recent advances in nutrition science have shown that foods and diet patterns, rather than nutrient focused metrics, explain many effects of diet on non-communicable disease”

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Growing realisation of the importance of overall diet patterns has stimulated not only scientific inquiry but also a deluge of empirical, commercial, and popular dietary patterns of varying origin and scientific backing.

“Growing realisation of the importance of overall diet patterns has stimulated not only scientific inquiry but also a deluge of empirical, commercial, and popular dietary patterns of varying origin and scientific backing.48”

• cites [48] US News and World Report. Best diets. 2018. https://health.usnews.com/best-diet.Not checked yet

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The policy construct used for sugar sweetened drinks breaks down for incentivising consumption of healthy foods.

“This construct breaks down for incentivising consumption of healthy foods.”

• AssumptionRests on an assumption: Most policy innovation has focused on sugar sweetened drinks, following the WHO Framework Convention on Tobacco Control model of tax, restrict places of sale, restrict marketing, and warning labels.