How, as individuals, should we approach nutrition and healthy weight control?

1. How, as individuals, should we approach nutrition and healthy weight control? Susan B. Roberts, PhD Professor of Nutrition & Professor of Psychiatry Director of the Energy Metabolism Laboratory, USDA Nutrition Center Scientific Staff Member in Pediatrics Tufts University and Tufts Medical School

2. How To Weigh Yourself And Get The Most Accurate Results “I can’t believe I was doing it wrong all these years.”

3. Some Statistics • Rates of obesity started rising in the mid-1980s- Adults: 2/3 now overweight or obese- Children: 1/5 now ow/obese and rising • 51% adults diet in any given year • Using currently available diet methods, people who intentionally lose weight typically regain all lost weight

4. Consumed Energy Balance and Weight Control in Adults Holidays & vacations Decreasing metabolism Eating out a lot Pregancy-gain Big portions Lack of exercise Expended 3000 Stress-eating • To prevent obesity, energy intake = total energy expenditure 2500 Love of good food! 2000 • Weight gain happens when intake > expenditure. kcal/day 1500 • Removing all the causes of weight gain creates neutral not negative energy balance. 1000 500 • It’s easy to overeat, hard to undereat! The 2/3 population who are overweight/obese need effective methods for sustainable negative energy balance

5. 45 40 35 30 25 20 15 10 0 1 2 3 4 5 6 0 1 2 3 4 5 6 Summary of Changes in Body Fat in 50 Long-Term Exercise Intervention Studies Elder & Roberts. Nutr Rev 2007;65:1 45 40 • 1 hr/day absolute max achieved (less in women) • Small effect exercise on fatness • 1 hr/d of jogging  -3.5% body fat over 6 mo (≈6 lb weight) 35 Regression of Change in Women 30 Body Fat (%) 25 20 15 10 Regression of Change in Men Body Fat (%) Net Energy Cost of Exercise Training Per Week (1000 kcal)

6. What Happened? 3000 2500 • Increase of 564 kcal/d in food supply. • 2 foods account for most of the increase: - high fructose corn syrup - oil • Per Capita Food Supply Corrected for Waste (kcal/day) 2000 • 4 more contribute a bit: - flour - cheese - shortening - edible beef tallow 1500 1000 • What didn’t increase: beef, seafood, candy, chocolate, chips, cream (and ice cream and frozen desserts decreased 13%) 1975 1980 1985 1990 1995 2000 2005

7. A problem of energy intake or energy expenditure? • Weight loss and prevention of weight regain require reducing energy intake relative to energy expenditure. Given the 500+ calorie increase in energy intake since 1975, a decrease in energy intake is easily justified as practical solution • Amounts of exercise required to reduce BMI values to a healthy range unlikely to be achievable and therefore hard to justify as practical solution Is reducing energy intake a society problem or and individual problem?

8. Restaurants as one example of our food environment, and their impact broadly considered

9. Multi-Site Study of Randomly-Selected Restaurant Foods Urban et al. JAMA 2011 • Study of 269 randomly selected restaurant foods from MA, AR, IN • Average stated calories were accurate BUT low calorie foods in sit-down restaurants contained 7% more calories than stated. • Sides on average contained more calories than the entrée they accompanied. • Estimated impact on body weight if self-monitoring energy intake: ≈+10 lb/year

10. Excess Energy Intake Relative to Requirements in Most Restaurant Meals(Urban et al, in preparation) 667 kcal 500 kcal • Study of 170 restaurant meals from 9 most popular ethnic categories in 36 randomly selected restaurants in Greater Boston area • Average stated calorie contents were 1276 kcal. • Represents 2.0-2.5 times healthy meal size for maintaining energy balance, and ≈100% daily energy intake for individual trying to lose weight.

11. Why do humans eat the way they do and like the things they like? AVAILABILITY: eating just because its there Bad Popcorn in Big Buckets(Wansink & Kim, 2005) • Moviegoers were given free popcorn - fresh or stale - medium or large. • Amount consumed was significantly greater for larger portions even when the popcorn was stale.

12. Underestimation of energy content of large portions (Chandon & Wansink, 2007) • Small, medium and large meals were chosen at McDonald’s and Subway and volunteers estimated energy intake. • Greater underestimation of energy intake with larger portions in both restaurant meals Estimated energy intake, kcal/portion Portion energy intake, kcal/portion

13. Hedonic Pleasure(1º orbitofrontal cortex) Hunger-Satiety(1º hypothalmus) Reward ( “need”)(1º nucleus accumbens) An Optimal Weight Control Diet Satisfies The Three Distinct Neurological Systems That Regulate Feeding Behavior

14. Hunger & Satiety Reward & Pleasure An optimal weight control diet will give a sustainable balance between reward/pleasure and hunger/satiety

15. Neurological rather than psychological explanations external control • And trigger the ‘cephalic phase of digestion’ in unconscious lower brain which: • Increases real metabolic hunger signals (↓ blood glucose) • Relaxes stomach muscles (so larger stomach volume, needs more food for satiety) • Accelerates GI motility (more rapid digestion speeds return of hunger and desire to eat again sooner The senses report what’s out there to hunger-satiety and reward/pleasure centers: • Sight • Smell • Taste internal control • Afferent signals (body to brain) report bodily needs to hunger-satiety and reward/pleasure centers: • Vagal nerves from stomach & lower GI • Gut hormones from stomach & ileum • Circulating nutrients (glucose & FFA in blood) • Fat cell hormones such as leptin • Post ingestive conditioning (eg dopamine reward in midbrain) anticipates and maintains reward for eating high calorie foods and familiar foods

16. What it all means… • In effect, our environment controls:- our metabolism- our hunger- our synthesis of neurotransmitters such as dopamine that keep us eating- when there is more food we eat more to feel adequately satisfied Explains why an increasingly toxic food environment made us eat an extra 564 kcal/d of HF corn syrup and oil since 1975! • People feel guilty about weight gain, but for the most part we overeat to feel we areeating normally, because environmental control over hunger and metabolism happens in our lower unconscious brain

17. In the ideal world… Consumers • Would take charge. Diet sensibly. Make their work food environment better for weight control. As parents, get involved in school food. • Would refuse advertising for foods that promote obesity and untested gimmicks and diets falsely implying more weight loss that typically achievable. Media Government • Accept that the obesity crisis won’t be solved without much more federal government involvement. • Get economists and nutrition scientists together to work out how you can change the food environment. Introducing healthy choices won’t be enough! • Think big. This is not just about regulating school food. Could fuel emission standards be a model for restaurants and food companies? Federal junk food taxes? Subsidized weight programs? • Continue ongoing efforts to eliminate: - false claims of rapid weight loss - food advertisements that encourage overeating

18. Individual Energy regulation: influenced by several factors • HUNGER: the need to feel satisfied • AVAILABILITY: eating just because its there • CALORIE DENSITY: what we like most • VARIETY: passive overeating and sensory specific satiety • FAMILIARITY: maintaining established eating habits (just because they are familiar)

19. Hunger: Not All Calories Are Equal • Fiber • Glycemic Index • Protein • Volume Western vs. Paleolithic Diet (Eaton et al. 1997) Dietary factors that reduce hunger and/or increase satiety relative to energy intake (mg/d) Liquid calories have the opposite effect of no satiety despite high calories

20. Effects of a Combined Nutrition and Behavioral Weight Loss Intervention in Worksites(Salinardi, Batra et al, in preparation) • A RCT of a 6 mo worksite weight loss program was conducted in 4 worksites (2 for profit, 2 non-profit) with 100-500 employees in Greater Boston. • Control sites were wait listed for the program. • Individuals in intervention sites with BMI >25 kg/m2 could sign up for a comprehensive behavioral intervention involving weekly group meetings for 16 weeks and then biweekly meetings for 8 weeks. • 14% total employees enrolled and 89% of enrollees completed the 6 month program. Weight loss was significant in both intervention sites.

21. Summary Positive and negative energy balance are different states: easy to be in positive energy balance, hard to be in negative energy balance. Implication 1: unlikely to resolve the obesity epidemic with community-level prevention measures alone Implication 2: need greater emphasis on developing effective, sustainable, cost-effective weight loss interventions for the 2/3 population already overweight or obese