rena r. wing, ph.d. professor of psychiatry and human behavior brown medical school

Rena R. Wing, Ph.D.Rena R. Wing, Ph.D.Professor of Psychiatry and Human BehaviorProfessor of Psychiatry and Human Behavior

Brown Medical SchoolBrown Medical SchoolDirector, Weight Control & Diabetes Research CenterDirector, Weight Control & Diabetes Research Center

The Miriam HospitalThe Miriam Hospital

Brain and Behavior:

Obesity and Weight Control

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: G7-G13, 2004; 10,1152/ajpgi. 00448.2003.

• Body Mass Index (BMI):Body Mass Index (BMI): kg / mkg / m22

weight in kilograms divided by height in meters squaredweight in kilograms divided by height in meters squared

• Obese: BMI Obese: BMI >> 30 30

• Body Mass Index (BMI):Body Mass Index (BMI): kg / mkg / m22

weight in kilograms divided by height in meters squaredweight in kilograms divided by height in meters squared

• Obese: BMI Obese: BMI >> 30 30

Obesity Trends Among U.S. Adults between 1985 and 2002

Obesity Trends Among U.S. Adults between 1985 and 2002

Obesity Trends* Among U.S. AdultsBRFSS, 1985

No Data <10% 10%–14%

(*BMI ≥30, or ~ 30 lbs overweight for 5’ 4” woman)


No Data <10% 10%–14%



No Data <10% 10%–14% 15%–19%



No Data <10% 10%–14% 15%–19% ≥20



No Data <10% 10%–14% 15%–19% 20%–24% ≥25%


Source: Behavioral Risk Factor Surveillance System, CDC

No Data <10% 10%–14% 15%–19% 20%–24% ≥25%



Overweight & Obesity Overweight & Obesity in Rhode Island (2003)in Rhode Island (2003)

OverweightOverweight 38.5%38.5%

ObeseObese 18.4%18.4%

TOTALTOTAL 56.9%56.9%

Toxic Environment: Toxic Environment: Sedentary lifestylesSedentary lifestyles

• TelevisionTelevision

• ComputersComputers

• Cell phonesCell phones

• Remote controlsRemote controls

Physiological

Sociocultural

Individual/Behavioral

AAntecedents

BBehaviors

CConsequences

AAntecedents

BBehaviors

CConsequences

Low fat, Low Calorie Diet, Physical Activity

AAntecedents

BBehaviors

CConsequences


Stimulus Control

Changing Thoughts

and Feelings

Self-Monitoring, Goal-setting

Positive Reinforcers

Contingency

Contracts

Source of Calories

• Fat ………………Fat ……………… 9 calories/gram9 calories/gram

• Carbohydrates ….Carbohydrates …. 4 calories/gram4 calories/gram

• Protein ………….Protein …………. 4 calories/gram4 calories/gram

• Alcohol …………Alcohol ………… 7 calories/gram7 calories/gram

Low Calorie - Low Fat Diet Recommendations

Weight < 200 lbsWeight < 200 lbs

1000 - 12001000 - 1200

20 - 30%20 - 30%

22 - 4022 - 40

Weight > 200 lbsWeight > 200 lbs

1500 - 18001500 - 1800

20 - 30%20 - 30%

33 - 6033 - 60

Calories

Fat %

Fat (g)

Mean Percent Change in Weight among Subjects on the Low Carbohydrate Diet and Those on the Conventional Diet

Baseline Carried Forward Analysis

0

2

4

6

8

10

12

Cha

nge

in W

eigh

t (%

)

0 3 6 9 12Month

Low-carbohydrate diet

Conventional diet

* *

NEJM 348;21 2003

Weight Loss Maintenance Using Meal Replacements

0

2

4

6

8

10

12

Per

cen

tag

e re

du

ctio

n i

n i

nit

ial

wei

gh

t

Time (months)Ditschuneit et al., AJCN; 1999; 69: 198-204

Standard then Meal Replacement

Meal Replacement

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28

Law of Thermodynamics

Resting Metabolic Rate (65%)Resting Metabolic Rate (65%)

Thermic Effect of Food (10%)Thermic Effect of Food (10%)

Exercise Exercise

(25%)(25%)

Food and liquid intakeFood and liquid intake

(100%)(100%)

Energy OutEnergy OutEnergy InEnergy In

1.1. Does exercise alone produce weight loss?Does exercise alone produce weight loss?

YesYes – but modest (2-4 kg) – but modest (2-4 kg)

• Does diet and exercise produce greater initial Does diet and exercise produce greater initial

weight loss than diet only?weight loss than diet only?

YesYes – but modest (2 kg) – but modest (2 kg)

• Does diet and exercise produce better long-Does diet and exercise produce better long-

term weight loss than diet only?term weight loss than diet only?

YesYes

Long Term Weight Loss

Study Diet Only Diet + ExercisePavlou 18 mo -3 -11Sikand 2 yr -0.8 -9.2Skendner 1 yr -6.8 -8.9

2 yr +0.9 -2.2Wadden 1 yr -15.3 -13.5

2 yr -6.9 -8.5Wing 1 yr -3.8 -7.9Wing 1 yr -5.5 -7.4

2 yr -2.1 -2.5

Physical Activity StrategiesPhysical Activity Strategies

• Short boutsShort bouts

• Home exerciseHome exercise

• Aerobic vs resistanceAerobic vs resistance

0

-2

-4

-6

-8

-10

-12

-14

-166 12 18

Cha

nge

in B

ody

Wei

ght,

kg <150 min/wk

>150 min/wk

>200 min/wk

Dose Response of Exercise on Weight Loss

Time, mo

AAntecedents

BBehaviors

CConsequences


Stimulus Control

Changing Thoughts

and Feelings

Self-Monitoring, Goal-setting

Positive Reinforcers

Contingency

Contracts

Modest Weight Loss Improves HealthModest Weight Loss Improves Health

•Improves glycemic control Improves glycemic control

•Improves cardiovascular risk factors Improves cardiovascular risk factors

•Improves psychological well-beingImproves psychological well-being

•Prevents or delays onset of type 2 diabetesPrevents or delays onset of type 2 diabetes

Diabetes Prevention ProgramDiabetes Prevention Program

• Over 3000 overweight adults with impaired Over 3000 overweight adults with impaired glucose toleranceglucose tolerance

• Randomly assigned to:Randomly assigned to:– Intensive lifestyle interventionIntensive lifestyle intervention

– MetforminMetformin

– PlaceboPlacebo

• Followed annually for over 3 yearsFollowed annually for over 3 years

Goal-based Behavioral InterventionGoal-based Behavioral Intervention

• An intensive program with the following An intensive program with the following

specific goals:specific goals:

>> 7% loss of body weight and maintenance 7% loss of body weight and maintenance

of weight lossof weight loss

>> 150 minutes/week of physical activity 150 minutes/week of physical activity

Lifestyle Intervention ResultsLifestyle Intervention Results

•Average activity = 225 minutes/weekAverage activity = 225 minutes/week

– 74 % met goal at week 2474 % met goal at week 24

–58% met goal at end of study58% met goal at end of study

•Average weight loss = 7% (7 kg or 14 lb) at Average weight loss = 7% (7 kg or 14 lb) at week 24 and 4% (4 kg or 8.8 lb) at end of week 24 and 4% (4 kg or 8.8 lb) at end of studystudy

–50% met 7% weight goal at week 2450% met 7% weight goal at week 24

–38% met 7% weight goal at end of study38% met 7% weight goal at end of study

-8

-6

-4

-2

0

0 1 2 3 4

Years from Randomization

Wei

ght C

hang

e (k

g)

Placebo

Metformin

Lifestyle

Mean Weight ChangeMean Weight Change

The DPP Research Group, NEJM 346:393-403, 2002

0 1 2 3 4

0

10

20

30

40Placebo (n=1082)Metformin (n=1073, p<0.001 vs. Plac)Lifestyle (n=1079, p<0.001 vs. Met , p<0.001 vs. Plac )

Percent developing diabetes

All participants

All participants

Years from randomization

Cum

ulat

ive

inci

denc

e (%

)Incidence of DiabetesIncidence of Diabetes

Risk reductionRisk reduction31% by metformin31% by metformin58% by lifestyle58% by lifestyle

BRFSS (1996) Data BRFSS (1996) Data BMI 25-27BMI 25-27

Physician Advised to Lose WeightPhysician Advised to Lose Weight

No ComorbiditiesNo Comorbidities 5.6%5.6%

Yes ComorbiditiesYes Comorbidities 13.6%13.6%

Trying to Lose WeightTrying to Lose Weight

If not advised If not advised 33.4%33.4%

If advisedIf advised 77.5%77.5%

National Weight Control Registry National Weight Control Registry (NWCR)(NWCR)

• Founded in 1993 by Drs. Rena Wing and James HillFounded in 1993 by Drs. Rena Wing and James Hill

• Registry of “successful losers”Registry of “successful losers”

• Minimum of 30 lbs of weight loss for a minimum of Minimum of 30 lbs of weight loss for a minimum of one yearone year

• >> 18 years of age 18 years of age

National Weight Control RegistryNational Weight Control Registry

• Over 4,000 members Over 4,000 members

• Weight loss averages 30 kgWeight loss averages 30 kg– 28.7 kg in women28.7 kg in women

– 35 kg in men35 kg in men

• Maintained the minimum weight loss (13.6 kg) for Maintained the minimum weight loss (13.6 kg) for

5.5 years5.5 years

• 16% maintained the minimum weight loss > 10 16% maintained the minimum weight loss > 10

yearsyears

NWCR: Maintenance StrategiesNWCR: Maintenance Strategies

• No similarity in how weight was lostNo similarity in how weight was lost

• Great similarity in how weight is being Great similarity in how weight is being

maintainedmaintained

– Low fat, low calorie dietLow fat, low calorie diet

– High daily levels of physical activityHigh daily levels of physical activity

– Frequent self-monitoringFrequent self-monitoring

Current Eating HabitsCurrent Eating Habits

• Average intake: 1380 kcalsAverage intake: 1380 kcals

• Average 24% fatAverage 24% fat

• Average 5 meals per dayAverage 5 meals per day

• Most eat breakfast dailyMost eat breakfast daily

• Eat out 3 meals/weekEat out 3 meals/week

• Very few follow an “Atkins” type of dietVery few follow an “Atkins” type of diet

Physical Activity in the NWCRPhysical Activity in the NWCR

• 91% report physical activity as an important 91% report physical activity as an important aspect of weight maintenanceaspect of weight maintenance

• Most NWCR members far exceeded the 150 Most NWCR members far exceeded the 150 minutes per week physical activity goal that is minutes per week physical activity goal that is recommended by the Surgeon Generalrecommended by the Surgeon General

• Average of 2600 calories per week of physical Average of 2600 calories per week of physical activity (equivalent to 1 hour per day)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

rena r. wing, ph.d. professor of psychiatry and human behavior brown medical school

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