Brain and Behavior Obesity and Weight Control Rena
Brain and Behavior: Obesity and Weight Control Rena R. Wing, Ph. D. Professor of Psychiatry and Human Behavior Brown Medical School Director, Weight Control & Diabetes Research Center The Miriam Hospital Brain & Behavior April 2005
Weight = Energy In – Energy Out
Accuracy: • Energy intake in one year = 955, 000 calories • Gaining one pound in one year = 3, 500 calories • Error of 0. 4% or 11 calories per day will produce a weight gain of one pound
Am J Physiol Gastrointest Liver Physiol 286: G 7 -G 13, 2004; 10, 1152/ajpgi. 00448. 2003.
Obesity Trends Among U. S. Adults between 1985 and 2002 • Body Mass Index (BMI): kg / m 2 weight in kilograms divided by height in meters squared • Obese: BMI > 30
Obesity Trends* Among U. S. Adults BRFSS, 1985 (*BMI ≥ 30, or ~ 30 lbs overweight for 5’ 4” woman) No Data <10% 10%– 14%
Obesity Trends* Among U. S. Adults BRFSS, 1986 (*BMI ≥ 30, or ~ 30 lbs overweight for 5’ 4” woman) No Data <10% 10%– 14%
Obesity Trends* Among U. S. Adults BRFSS, 1987 (*BMI ≥ 30, or ~ 30 lbs overweight for 5’ 4” woman) No Data <10% 10%– 14%
Obesity Trends* Among U. S. Adults BRFSS, 1988 (*BMI ≥ 30, or ~ 30 lbs overweight for 5’ 4” woman) No Data <10% 10%– 14%
Obesity Trends* Among U. S. Adults BRFSS, 1989 (*BMI ≥ 30, or ~ 30 lbs overweight for 5’ 4” woman) No Data <10% 10%– 14%
Obesity Trends* Among U. S. Adults BRFSS, 1990 (*BMI ≥ 30, or ~ 30 lbs overweight for 5’ 4” woman) No Data <10% 10%– 14%
Obesity Trends* Among U. S. Adults BRFSS, 1991 (*BMI ≥ 30, or ~ 30 lbs overweight for 5’ 4” woman) No Data <10% 10%– 14% 15%– 19%
Obesity Trends* Among U. S. Adults BRFSS, 1992 (*BMI ≥ 30, or ~ 30 lbs overweight for 5’ 4” woman) No Data <10% 10%– 14% 15%– 19%
Obesity Trends* Among U. S. Adults BRFSS, 1993 (*BMI ≥ 30, or ~ 30 lbs overweight for 5’ 4” woman) No Data <10% 10%– 14% 15%– 19%
Obesity Trends* Among U. S. Adults BRFSS, 1994 (*BMI ≥ 30, or ~ 30 lbs overweight for 5’ 4” woman) No Data <10% 10%– 14% 15%– 19%
Obesity Trends* Among U. S. Adults BRFSS, 1995 (*BMI ≥ 30, or ~ 30 lbs overweight for 5’ 4” woman) No Data <10% 10%– 14% 15%– 19%
Obesity Trends* Among U. S. Adults BRFSS, 1996 (*BMI ≥ 30, or ~ 30 lbs overweight for 5’ 4” woman) No Data <10% 10%– 14% 15%– 19%
Obesity Trends* Among U. S. Adults BRFSS, 1997 (*BMI ≥ 30, or ~ 30 lbs overweight for 5’ 4” woman) No Data <10% 10%– 14% 15%– 19% ≥ 20
Obesity Trends* Among U. S. Adults BRFSS, 1998 (*BMI ≥ 30, or ~ 30 lbs overweight for 5’ 4” woman) No Data <10% 10%– 14% 15%– 19% ≥ 20
Obesity Trends* Among U. S. Adults BRFSS, 1999 (*BMI ≥ 30, or ~ 30 lbs overweight for 5’ 4” woman) No Data <10% 10%– 14% 15%– 19% ≥ 20
Obesity Trends* Among U. S. Adults BRFSS, 2000 (*BMI ≥ 30, or ~ 30 lbs overweight for 5’ 4” woman) No Data <10% 10%– 14% 15%– 19% ≥ 20
Obesity Trends* Among U. S. Adults BRFSS, 2001 (*BMI ≥ 30, or ~ 30 lbs overweight for 5’ 4” woman) No Data <10% 10%– 14% 15%– 19% 20%– 24% ≥ 25%
Obesity Trends* Among U. S. Adults BRFSS, 2002 (*BMI ≥ 30, or ~ 30 lbs overweight for 5’ 4” woman) No Data <10% 10%– 14% 15%– 19% 20%– 24% Source: Behavioral Risk Factor Surveillance System, CDC ≥ 25%
Overweight & Obesity in Rhode Island (2003) Overweight 38. 5% Obese 18. 4% TOTAL 56. 9%
Toxic Environment: Sedentary lifestyles • Television • Computers • Cell phones • Remote controls
Physiological Individual/ Behavioral Sociocultural
A Antecedents B Behaviors C Consequences
A Antecedents B Behaviors Low fat, Low Calorie Diet, Physical Activity C Consequences
A Antecedents B Behaviors C Consequences Low fat, Low Calorie Diet, Physical Activity Stimulus Control Changing Thoughts and Feelings Self-Monitoring, Goal-setting Positive Reinforcers Contingency Contracts
Source of Calories • Fat ……………… 9 calories/gram • Carbohydrates …. 4 calories/gram • Protein …………. 4 calories/gram • Alcohol ………… 7 calories/gram
Low Calorie - Low Fat Diet Recommendations Weight < 200 lbs Weight > 200 lbs Calories 1000 - 1200 1500 - 1800 Fat % 20 - 30% Fat (g) 22 - 40 33 - 60
Mean Percent Change in Weight among Subjects on the Low Carbohydrate Diet and Those on the Conventional Diet Baseline Carried Forward Analysis * * Conventional diet Low-carbohydrate diet 0 3 6 Month 9 12 NEJM 348; 21 2003
Weight Loss Maintenance Using Meal Replacements Standard then Meal Replacement 0 2 4 6 8 10 12 14 16 18 20 22 24 Ditschuneit et al. , AJCN; 1999; 69: 198 -204 Time (months) 26 28
Law of Thermodynamics Energy In Food and liquid intake Energy Out Resting Metabolic Rate (65%) (100%) Thermic Effect of Food (10%) Exercise (25%)
1. Does exercise alone produce weight loss? Yes – but modest (2 -4 kg) • Does diet and exercise produce greater initial weight loss than diet only? Yes – but modest (2 kg) • Does diet and exercise produce better longterm weight loss than diet only? Yes
Long Term Weight Loss Study Pavlou Sikand Skendner Wadden Wing 18 mo 2 yr 1 yr 2 yr Diet Only -3 -0. 8 -6. 8 +0. 9 -15. 3 -6. 9 -3. 8 -5. 5 -2. 1 Diet + Exercise -11 -9. 2 -8. 9 -2. 2 -13. 5 -8. 5 -7. 9 -7. 4 -2. 5
Physical Activity Strategies • Short bouts • Home exercise • Aerobic vs resistance
Dose Response of Exercise on Weight Loss Change in Body Weight, kg 0 <150 min/wk -2 -4 -6 >150 min/wk -8 -10 -12 >200 min/wk -14 -16 6 12 Time, mo 18
A Antecedents B Behaviors C Consequences Low fat, Low Calorie Diet, Physical Activity Stimulus Control Changing Thoughts and Feelings Self-Monitoring, Goal-setting Positive Reinforcers Contingency Contracts
Modest Weight Loss Improves Health • Improves glycemic control • Improves cardiovascular risk factors • Improves psychological well-being • Prevents or delays onset of type 2 diabetes
Diabetes Prevention Program • Over 3000 overweight adults with impaired glucose tolerance • Randomly assigned to: – – – Intensive lifestyle intervention Metformin Placebo • Followed annually for over 3 years
Goal-based Behavioral Intervention • An intensive program with the following specific goals: > 7% loss of body weight and maintenance of weight loss > 150 minutes/week of physical activity
Lifestyle Intervention Results • Average activity = 225 minutes/week – 74 % met goal at week 24 – 58% met goal at end of study • Average weight loss = 7% (7 kg or 14 lb) at week 24 and 4% (4 kg or 8. 8 lb) at end of study – 50% met 7% weight goal at week 24 – 38% met 7% weight goal at end of study
Mean Weight Change Placebo Metformin Lifestyle The DPP Research Group, NEJM 346: 393 -403, 2002
Incidence of Diabetes Risk reduction 31% by metformin 58% by lifestyle
BRFSS (1996) Data BMI 25 -27 Physician Advised to Lose Weight No Comorbidities 5. 6% Yes Comorbidities 13. 6% Trying to Lose Weight If not advised 33. 4% If advised 77. 5%
National Weight Control Registry (NWCR) • Founded in 1993 by Drs. Rena Wing and James Hill • Registry of “successful losers” • Minimum of 30 lbs of weight loss for a minimum of one year • > 18 years of age
National Weight Control Registry • Over 4, 000 members • Weight loss averages 30 kg – 28. 7 kg in women – 35 kg in men • Maintained the minimum weight loss (13. 6 kg) for 5. 5 years • 16% maintained the minimum weight loss > 10 years
NWCR: Maintenance Strategies • No similarity in how weight was lost • Great similarity in how weight is being maintained – Low fat, low calorie diet – High daily levels of physical activity – Frequent self-monitoring
Current Eating Habits • Average intake: 1380 kcals • Average 24% fat • Average 5 meals per day • Most eat breakfast daily • Eat out 3 meals/week • Very few follow an “Atkins” type of diet
Physical Activity in the NWCR • 91% report physical activity as an important aspect of weight maintenance • Most NWCR members far exceeded the 150 minutes per week physical activity goal that is recommended by the Surgeon General • Average of 2600 calories per week of physical activity (equivalent to 1 hour per day)
CONCLUSION • Modest weight loss improves health • Most effective programs include low calorie/low fat diet, physical activity, and behavior modification • Health-care providers are in a unique position to assess, advise, and reinforce weight loss efforts
- Slides: 57