U.S. Dietary Guidelines: Sweet or Sour

Transcription

1 U.S. Dietary Guidelines: Sweet or Sour Roger Clemens, DrPH, CFS, CNS, FACN, FIFT, FIAFST Adj Professor, Pharmacology and Pharmaceutical Sciences, USC School of Pharmacy, Los Angeles

2 Degree of Specificity The Evolution of Food Control Government audits on sales based on usage, nationalized food companies Litigation, class action suits Ban, ration Restrictions on license to sell; zoning restrictions Warning labels, changes to GRAS status Information Better-foryou Foods Nutrition standards used to tax, restrict marketing & advertising, restrict access, limit eligibility in food assistance Self-regulation based on nutrition standards No Good Food/Bad Food; All Foods Fit Regulation Courtesy of Bill Layden Degree of Command & Control 2

3 Dietary Guidance Milestones Dietary Guidelines for Americans (USDA/HHS) 1980 Dietary Guidelines for Americans (HHS/USDA) 1995 Dietary Guidelines for Americans (HHS/USDA) 1990 Dietary Guidelines for Americans (HHS/USDA) 2005 Dietary Guidelines for Americans (HHS/USDA) / McGovern Report - Dietary Goals (6) 1985 Dietary Guidelines for Americans (USDA/HHS) 2000 Dietary Guidelines for Americans (USDA/HHS) Dietary Guidelines for Americans (USDA/HHS) Surgeon General's Report on Health Promotion 3

4 Dietary Guidelines for Americans: The Core of Nutrition Policy

5 Sugar Recommendations The First 30 Years 1980 Avoid too much 1985 Avoid too much 1990 Use only in moderation 1995 Choose diet moderate in sugars 2000 Choose foods to moderate sugar intake 2005 No guidance 2010 Reduce added sugars (<25%en) 2015 Limit added sugar to <10%en 5

6 Hierarchy of Evidence Systematic review/ meta-analysis RCTs Decreasing bias RCT Systematic review/meta-analysis NRCTs Non-randomized controlled trial (NRCT) Systematic review/meta-analysis cohort/case-control studies cohort study/case-control study Cross-sectional study Case series/time series Expert opinion

7 Assessing the Evidence Observational claims are not necessarily validated via clinical trials. Clinical studies among small populations do not necessarily translate to total population (think public policy) Common words like association, related, and relative risk imply strength, yet upon review the work is generally quite weak Definitive solution will not come from another million observational papers or a few small randomized trials Ioannidis JPA BMJ 2013;347: doi: /bmj.f6698 7

8 Research Bias Systematic reviews and meta-analyses Different inclusion/exclusion criteria impact results Different statistical approaches and choices of covariates impact results Dietary exposures are not accurate Associations Causes Nicklas et al., J Nutr doi: /jn

9 Ecological relation of water intake with prevalence of Overweight/Obesity: Kaiser et al. Obes Rev Jun 7. doi: /obr

10 WHO The issue: free sugars contribute to untoward health effects Dental caries Maintain or reduce body weight Free sugars monosaccharides and disaccharides added to foods by the manufacturer, cook or consumer, and sugars naturally present in honey, syrups, fruit juices and fruit concentrates. WHO, Draft guidelines on free sugars released for public consultation, 5 March

11 WHO Recommendations Reduce intake of free sugars throughout the life-course (strong recommendation1). Intake of free sugars not exceed 10% of total energy2 (strong recommendation). Intake of free sugars reduce to below 5% of total energy (conditional recommendation3). WHO, Draft guidelines on free sugars released for public consultation, 5 March

12 Sugars: The New Dominant Public Health Issue Foundational Manuscripts: Te Morenga et al., Dietary sugars and body weight: systematic review and meta-analysis of randomised controlled trials and cohort studies. BMJ 2013;346:e7492 Isoenergetic exchange of dietary sugars with other carbohydrates showed no change in body weight (0.04 kg, 0.04 to 0.13). Hypercaloric ad libitum diets increased sugars intake was associated with a comparable weight increase (0.75 kg, 0.30 to 1.19; P=0.001). Hypocaloric ad libitum diets reduced intake of dietary sugars was associated with a decrease in body weight (0.80 kg, 95% confidence interval 0.39 to 1.21; P<0.001); 12

13 SACN Report Assessed 67 prospective studies and 41 RCTs for relationships among sugar and health outcomes Coronary events: no association Blood pressure: no effect Fasting blood lipids (e.g., cholesterol, LDL, HDL): no effect or limited evidence Energy: greater consumption weight gain Diabetes & insulin: no association or limited evidence Colon cancer: no association Childhood BMI: no association or limited evidence 13 Accessed June 25, 2014

14 Added Sugars and Body Weight There is insufficient evidence that an exchange of sugar for non-sugar carbohydrates results in lower body weights (a calorie = a calorie) Observational (cross-sectional) studies suggest a possible relationship between consumption of sugarsweetened beverages (SSB) and body weight; no supporting RCTs Insufficient evidence to support a difference between liquid and solid sugar intake and body weight control Key reference: van Baak & Astrup. Obes Rev 2009; 10 Suppl 1:

15 Te Morenga et al. BMJ. 2012;345:e7492 Isoenergetic exchange of free sugars with other macronutrients does not affect body weight: WHO-commissioned systematic review and meta-analysis of 13 RCTs (n=144) 15

16 Te Morenga et al. BMJ. 2012;345:e7492 Addition of excess energy from sugars increases weight in adults: WHO commissioned systematic review and meta-analysis of 30 RCTs 16

17 Te Morenga et al. BMJ. 2012;345:e7492 Reduction in energy from sugar reduces excess body fatness in adults but not children: WHO commissioned systematic review and meta-analysis of 30 RCTs Children Adults 17

18 Yang et al., JAMA Intern Med 2014; doi: /jamainternmed Sugar in Research Headlines: Drink just one 12-ounce can of sugary soda every day, and you might be unwittingly increasing your risk of dying from heart disease, suggests a new study. Conclusions: Increased calories from added sugar associated with increased risk of CVD mortality Consumption of SSB (aka sugar) is associated with elevated CVD mortality Recommendation Limit intake of calories from added sugar 18

19 Putative Effects of Sugar* Adverse Outcome Increases weight in an isocaloric exchange with other macronutrients Increases weight in a hypercaloric diet Decreases weight in a hypo caloric diet Increases appetite resulting in weight gain Causes diabetes Provides unnecessary energy Strength of the Evidence None Moderate/Inconsistent Weak/Inconsistent None None Strong * Sugar defined as sucrose, glucose, fructose, or HFCS. A hypercaloric diet is defined as a diet in which energy intake exceeds energy expenditure, and a hypocaloric diet is defined as a diet in which energy intake is less than energy expenditure, thereby favoring weight gain and weight loss, respectively. Kahn R, Sievenpiper JL. Diabetes Care 2014;37:

20 Take away messages 1. Any threshold for the effect of sugars on body weight and cardiometabolic risk is highly dependent on energy balance. 2. There are many pathways to overconsumption leading to weight gain and its downstream consequences. Dietary patterns that bring these pathways together have the greatest influence on weight gain and cardiometabolic risk and represent the best opportunity for successful interventions. 3. Attention needs to remain focused on reducing overconsumption of all caloric foods (including those high in added sugars!), promoting healthier dietary patterns, and increasing physical activity. 20

21 Population Attributable Mortality risk in the U.S. How do SSBs Compare with Other Risk Factors? Deaths Attributable to Individual Risks (x 1000) among Both Sexes Smoking 467 High BP 395 High BMI 216 Physical Inactivity High Blood Glucose High LDL-C High Dietary Na Low Dietary Omega-3s High Dietary tfa Alcohol Use Low Intake F/V SSBs 25 Low Intake PUFA (reply SFA) Danaei et al. PLoS Med 2009;6(4): e doi: /journal.pmed

22 Practicality Food 2 servings Energy (kcal) Free Sugar (g) Total % EER Blueberries (fresh frozen, smoothie) Bananas (fresh, in smoothie) Tangerines (snacks on ride) Potatoes (raw, snacks) Green beans (fresh) Almonds (raw) Walnuts (raw)

23 Prevalence (%) Kcal/d Is there a demon in the field? Caloric Sweeteners HFCS Overweight Obese U.S. Dept of Agriculture. Economic Research Service 23

24 The Evidence isoenergetic exchange of sugars with other carbohydrates was not associated with weight change. Te Morenga et al., BMJ 2012;345:e7492 doi: /bmj.e7492 observational studies suggest a possible relationship between consumption of SSB and body weight, [however] there is currently insufficient supporting evident from RCTs of sufficient size and duration van Baak and Astrup, Obesity Rev 2009;10(suppl 1):

25 What s Driving Policy? strongest evidence for public health and health outcomes is from RCTs; [there] should be caution when communicating recommendations when clinical evidence or dietary intervention data are not available. Maki et al., Adv Nutr 2014;5(1):7-15 epidemiological studies [and statistical modeling from NHANES III] suggest higher intake of added sugar (>10%en) is associated with increased risk for CVD mortality. Yang et al., JAMA Intern Med 2014; doi: /jamainternmed

26 International Guidelines and Policies Approximately 60 countries recommend limit intake of added sugar Recommendations vary: qualitative, quantitative (energy based) Primary focus varies: dental caries, CVD, obesity promote healthful lifestyles Culturally appropriate foods Sanitation Clean water Clemens & Papanikolaou,

27 European Countries Europe (about 50 countries, 28 in EU) Diverse recommendations and advisories Some recommend limit sugar 10-15%en Some recommend general limit of sugar intake Some recommend limit SSB consumption 27

28 Warning Labels A California bill to require sugary soft drinks to carry labels warning of obesity, diabetes and tooth decay (Bill Monning, D; Central Coast) Labeling them instead would educate consumers about the dangers of consuming too much sugar without requiring a controversial measure like a tax Proposed legislation denied in senate appropriations committee; granted reconsideration Reconsidered in session of the CA state legislature (AB 155, Matt Debabneh of Van Nuys ([District 45]; introduced Jan 16, 2015 re: sales tax) Posted April 9, 2014; Accessed April 21,

29 While Diet Is Linked to Health, Much Confusion Exists About What to Eat and Under What Circumstances!! 29