* In randomized controlled trials, consumption of whole grain foods improves glucose-insulin control, LDL cholesterol, and possibly vascular function and inflammation;1 while dietary fiber reduces blood pressure and LDL cholesterol.  Consistent with these benefits, intake of foods containing whole grains or dietary fiber is associated in long-term observational studies with lower risk of long-term weight gain, diabetes, coronary heart disease, and certain cancers.2-5

In contrast, intakes of refined grains, starches, and added sugars are associated with adverse health outcomes, including long-term weight gain, diabetes, and coronary heart disease.6-9 Metabolic feeding studies confirm harms of refined carbohydrates,10 while clinical trials demonstrate weight loss and improved blood sugar control on diets that reduce refined carbohydrates and glycemic load.11-13 For foods containing a mix of grains and/or sugars, the ratio of total carbohydrate to fiber provides one useful measure of healthfulness, aiming to balance the relative proportions of whole grains, bran, refined starch, and sugars.14-17 Food Compass incorporates each of these factors, including contents of whole grain, dietary fiber, added sugar, and the ratio of carbohydrate to fiber; as well as other factors like protein, sodium, vitamins and minerals, degree of processing, and more.

In contrast to evidence for benefits of whole grains and dietary fiber and harms of refined starches and sugars, the current science suggests that minimally processed animal products are generally neutral for major health endpoints. In prospective observational studies, intakes of eggs and poultry are generally not associated with risk of cardiovascular events, diabetes, or cancers.5,18-21 In a few studies among patients who already have diabetes, eating eggs and dietary cholesterol is linked to higher risk of cardiovascular events, suggesting a potential interaction for cardiovascular endpoints between insulin resistance and dietary cholesterol, but more research is needed on this. In some long-term observational cohorts, cheese intake associates with modestly lower risk of stroke and diabetes; in other studies it appears more neutral.22-24 Dairy consumption is linked to higher risk of certain cancers.5

Intake of processed meats (i.e., red meat or poultry preserved with sodium or other additives) is associated with higher risk of heart disease, stroke, and diabetes, while unprocessed red meats are associated with higher risk of diabetes but have generally smaller associations with cardiovascular events.19,25,26 The high salt content, and possibly other preservatives like nitrites, in processed meats likely contribute to the higher risk of cardiovascular events.27 Heme iron, a risk factor for diabetes in animal experiments, gestational diabetes, and inborn errors of iron metabolism such as hemochromatosis, may also partly explain the higher risk of diabetes seen with both processed and unprocessed red meats.28-30 Red meat consumption is also associated with higher risk of cancer, in particular colorectal cancer.5 Red meats are also sources of nutrients, like protein, vitamin B12, and zinc. Food Compass incorporates and balances these various characteristics, including amounts of red meat, protein, vitamins, salt, nitrates, and processing, among other attributes.

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2. Mozaffarian D. Dietary and Policy Priorities for Cardiovascular Disease, Diabetes, and Obesity: A Comprehensive Review. Circulation. 2016;133(2):187-225.

3. Micha R, Shulkin ML, Penalvo JL, et al. Etiologic effects and optimal intakes of foods and nutrients for risk of cardiovascular diseases and diabetes: Systematic reviews and meta-analyses from the Nutrition and Chronic Diseases Expert Group (NutriCoDE). PLoS One. 2017;12(4):e0175149.

4. Weickert MO, Pfeiffer AFH. Impact of Dietary Fiber Consumption on Insulin Resistance and the Prevention of Type 2 Diabetes. The Journal of nutrition. 2018;148(1):7-12.

5. World Cancer Research Fund/ American Institute for Cancer Research. Continuous Update Project (CUP).

6. Livesey G, Taylor R, Livesey HF, et al. Dietary Glycemic Index and Load and the Risk of Type 2 Diabetes: A Systematic Review and Updated Meta-Analyses of Prospective Cohort Studies. Nutrients. 2019;11(6).

7. Mozaffarian D, Hao T, Rimm EB, Willett WC, Hu FB. Changes in diet and lifestyle and long-term weight gain in women and men. N Engl J Med. 2011;364(25):2392-2404.

8. Tang G, Wang D, Long J, Yang F, Si L. Meta-analysis of the association between whole grain intake and coronary heart disease risk. Am J Cardiol. 2015;115(5):625-629.

9. Aune D, Norat T, Romundstad P, Vatten LJ. Whole grain and refined grain consumption and the risk of type 2 diabetes: a systematic review and dose-response meta-analysis of cohort studies. Eur J Epidemiol. 2013;28(11):845-858.

10. Ludwig DS. Aways Hungry? New York: Grand Central Life and Style; 2016.

11. 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(12):968-979.

12. Viana LV, Gross JL, Azevedo MJ. Dietary intervention in patients with gestational diabetes mellitus: a systematic review and meta-analysis of randomized clinical trials on maternal and newborn outcomes. Diabetes Care. 2014;37(12):3345-3355.

13. Huntriss R, Campbell M, Bedwell C. The interpretation and effect of a low-carbohydrate diet in the management of type 2 diabetes: a systematic review and meta-analysis of randomised controlled trials. Eur J Clin Nutr. 2018;72(3):311-325.

14. Mozaffarian RS, Lee RM, Kennedy MA, Ludwig DS, Mozaffarian D, Gortmaker SL. Identifying whole grain foods: a comparison of different approaches for selecting more healthful whole grain products. Public Health Nutr. 2013;16(12):2255-2264.

15. Fontanelli MM, Micha R, Sales CH, Liu J, Mozaffarian D, Fisberg RM. Application of the </= 10:1 carbohydrate to fiber ratio to identify healthy grain foods and its association with cardiometabolic risk factors. Eur J Nutr. 2019.

16. Ghodsian B, Madden AM. Evaluating the </=10:1 wholegrain criterion in identifying nutrient quality and health implications of UK breads and breakfast cereals. Public Health Nutr. 2018;21(6):1186-1193.

17. Liu J, Rehm CD, Shi P, McKeown NM, Mozaffarian D, Micha R. A comparison of different practical indices for assessing carbohydrate quality among carbohydrate-rich processed products in the US. PLoS One. 2020;15(5):e0231572.

18. Abete I, Romaguera D, Vieira AR, Lopez de Munain A, Norat T. Association between total, processed, red and white meat consumption and all-cause, CVD and IHD mortality: a meta-analysis of cohort studies. Br J Nutr. 2014;112(5):762-775.

19. Yang X, Li Y, Wang C, et al. Meat and fish intake and type 2 diabetes: Dose-response meta-analysis of prospective cohort studies. Diabetes Metab. 2020.

20. Drouin-Chartier JP, Schwab AL, Chen S, et al. Egg consumption and risk of type 2 diabetes: findings from 3 large US cohort studies of men and women and a systematic review and meta-analysis of prospective cohort studies. Am J Clin Nutr. 2020.

21. Drouin-Chartier JP, Chen S, Li Y, et al. Egg consumption and risk of cardiovascular disease: three large prospective US cohort studies, systematic review, and updated meta-analysis. BMJ. 2020;368:m513.

22. Pimpin L, Wu JH, Haskelberg H, Del Gobbo L, Mozaffarian D. Is Butter Back? A Systematic Review and Meta-Analysis of Butter Consumption and Risk of Cardiovascular Disease, Diabetes, and Total Mortality. PLoS One. 2016;11(6):e0158118.

23. Mishali M, Prizant-Passal S, Avrech T, Shoenfeld Y. Association between dairy intake and the risk of contracting type 2 diabetes and cardiovascular diseases: a systematic review and meta-analysis with subgroup analysis of men versus women. Nutrition Reviews. 2019;77(6):417-429.

24. Sluijs I, Forouhi NG, Beulens JW, et al. The amount and type of dairy product intake and incident type 2 diabetes: results from the EPIC-InterAct Study. Am J Clin Nutr. 2012;96(2):382-390.

25. Kim K, Hyeon J, Lee SA, et al. Role of Total, Red, Processed, and White Meat Consumption in Stroke Incidence and Mortality: A Systematic Review and Meta-Analysis of Prospective Cohort Studies. J Am Heart Assoc. 2017;6(9).

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28. Micha R, Michas G, Mozaffarian D. Unprocessed red and processed meats and risk of coronary artery disease and type 2 diabetes–an updated review of the evidence. Curr Athero Rep. 2012;14(6):515-524.

29. Fernandez-Real JM, McClain D, Manco M. Mechanisms Linking Glucose Homeostasis and Iron Metabolism Toward the Onset and Progression of Type 2 Diabetes. Diabetes care. 2015;38(11):2169-2176.

30. Wang X, Fang X, Wang F. Pleiotropic actions of iron balance in diabetes mellitus. Reviews in endocrine & metabolic disorders. 2015;16(1):15-23.