My Most Provocative Recommendations to the USAJoint Commission on Sports Medicine

and SciencePhiladelphia, PA

February 27, 2001

Steven N. Blair

Professor

Arnold School of Public Health

University of South Carolina

Disclosures

• Medical/Scientific Advisory Boards– Jenny Craig, Inc– Alere– Technogym– Cancer Foundation for Life– Santech– Clarity Project

• Research Funding– NIH– Body Media– Coca Cola– Department of Defense

Outline• Activity/fitness, or obesity—which is most

important?• Misinformation about obesity and health• Quackery and nostrums about diet and

exercise• What should we do

– Discover the cause of the obesity epidemic– Expertise on the President’s Council on

Fitness, Sports & Nutrition– Equal attention to diet and physical activity– K-12 education on behavioral change– Increase gasoline tax

Activity/fitness is far more important than fatness as a

clinical or public health problem

Ranking of selected risk factors: 6 leading causes of death by income group, estimates for 2004

Percentage of total (total: 1.53 billion)

World Health Organization. http://www.who.int/healthinfo/global_burden_disease/global_health_risks/en/index.htm

Physical Activity and CRF as Predictors of All-cause Mortality

• 31,818 men and 10,555 women

• 1492 deaths in men during average follow-up of 14.6 years, and 230 deaths in women during average follow-up of 12.8 years

• PA mortality trends not significant after adj for CRF

• CRF trends significant after adj for PA

Phys Act CRF

Lee DC, et al. BJSM; pub online April 23, 2010

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

Adj RR*

<17 17-25 >25 <17 17-25 >25

Fit

Unfit

All-cause Mortality CVD Mortality*adjusted for age, exam year, smoking, alcohol, & parental historyLee CD, Blair SN, & Jackson AS. Am J Clin Nurt 1999; 69:373-80

RR for All-cause and CVD Mortality in Fit and Unfit

ACLS Men by Body Fat Categories

Body Fat% Body Fat%

Adjusted RR for All-Cause Mortality by Fitness and BMI, ACLS Women

0

0.5

1

1.5

2

2.5

3

3.5

4

Adj RR*

NormalWeight

Overweight Obese

Fit

Unfit

Farrell et al. Obes Res. 2002; 10:417-423

*adj for age, exam year,smoking, & healthstatus

CRF and %Body Fat on Mortality Risk in 13,155 Hypertensive Men

* Adjusted for age, exam year, physically inactive, family history, smoking, alcohol, resting SBP and DBP, & diabetes and hypercholesterolemia

Outline• Activity/fitness, or obesity—which is most

important?• Misinformation about obesity and health• Quackery and nostrums about diet and

exercise• What should we do

– Discover the cause of the obesity epidemic– Expertise on the President’s Council on

Fitness, Sports & Nutrition– Equal attention to diet and physical activity– K-12 education on behavioral change– Increase gasoline tax

Uncritical, Unfounded, or Unusual Comments about

Obesity and Health

JAMA Used Pages for This?• Obesity in the National

Football League. JAMA 2005; 293:1061-2–Nearly all were overweight

–More that 25% had Class 2 obesity

• In other words, NFL players are big

We must improve school lunches because American

children eat 50% of their calories at school.

Mrs. ObamaFebruary 2010

Which causes more deaths in the U.S.—smoking or obesity?

• ~40% of U.S. adults think obesity causes at least as many deaths as does smoking

• ~20% of U.S. adults think obesity causes more deaths than smoking

• The truth– Smoking causes ~440,000 deaths/year– Obesity causes ~110,000 deaths/year

Outline• Activity/fitness, or obesity—which is most

important?• Misinformation about obesity and health• Quackery and nostrums about diet and

exercise• What should we do

– Discover the cause of the obesity epidemic– Expertise on the President’s Council on

Fitness, Sports & Nutrition– Equal attention to diet and physical activity– K-12 education on behavioral change– Increase gasoline tax

Model in the Article1. Sky Reach-15 reps each side2. Speed Intervals-10 sec at a

moderate pace then 20 seconds at a fast pace for a total of 2 minutes

3. Bench Push-ups-15 reps4. Walking Lunge-2 minutes5. Tree Back Rows-15 reps6. Speed Intervals (same as #2)7. Jump Pull-ups-15 reps8. Speed Steps-up and down stairs

for 2 minutes9. Hanging Leg Raise-15 reps10.Speed Intervals (same as #2)

Drop 12 Pounds this Month• Lose 5 pounds the first week

– Consume 1200 kcal/day

– Do the 10 exercises/day (total of 40 min)

• Estimate her weight 100-110 pounds (~50 kg)

• Estimate the 40 min workout is an average increase of 4 times resting metabolic rate

• 1 MET=1 kcal/kg/hour– So, 4 x 50 X .66=132 kcal/workout

• Five pounds/week=calorie deficit of almost 16,000 calories

• Somehow the math doesn’t work

Outline• Activity/fitness, or obesity—which is most

important?• Misinformation about obesity and health• Quackery and nostrums about diet and

exercise• What should we do

– Discover the cause of the obesity epidemic– Expertise on the President’s Council on

Fitness, Sports & Nutrition– Equal attention to diet and physical activity– K-12 education on behavioral change– Increase gasoline tax

Causes of the Obesity Epidemic

It’s calories that count

Energy InEnergy In Energy OutEnergy OutBMRBMRThermic effect of foodThermic effect of foodMedia (TV,PC)Media (TV,PC)CarsCarsNo heavy labourNo heavy labourExerciseExercise

Portion sizePortion sizeHigh-fat foodsHigh-fat foodsEnergy denseEnergy denseLow-fiberLow-fiberSoft drinksSoft drinksSnack foodsSnack foods

Is the Average Total Daily Caloric Intake Increasing?

Trends in Energy IntakeNHANES 1971-2000

• Data sources– NHANES I—1971-1974– NHANES II—1976-1980– NHANES III—1988-1994– NHANES—1999-2000

• Surveys were representative samples of noninstitutionalized U.S. women and men aged 20 to 74 years

Source: MMWR Feb 6, 2004

Trends in Energy Intake1971 to 2000, Men, NHANES

0

500

1000

1500

2000

2500

3000

All Ages 20-39 y 40-59 y 60-74 y

1971-741976-801988-941999-00

Kcal/day

Source: MMWR Feb 6, 2004

Trends in Energy Intake1971 to 2000, Women, NHANES

0

500

1000

1500

2000

2500

All Ages 20-39 y 40-59 y 60-74 y

1971-741976-801988-941999-00

Kcal/day

Source: MMWR Feb 6, 2004

NHANES Survey Methods 1971-2000

• NHANES I and NHANES II– 24-hour dietary recall, Monday-Friday

• NHANES III and NHANES– 24-hour dietary recall, Monday-Sunday

• Other changes in methodology included better probing techniques and better training of interviewers

• Other changes in dietary behavior included more meals eaten away from home and increasing portion sizes

Obesity Epidemic Caused by Eating too Much, Claims Academic

• Average caloric expenditure in 1980– Women=950 kcal/day– Men=1380 kcal/day

• Average caloric intake is now 3,500 kcal/day

• “Over the past 25 years…there has been no change in our levels of physical activity” “there has been no change in energy expenditure”

Article on British Science Festival in the September 16, 2010 Daily Telegraph

Outline• Activity/fitness, or obesity—which is most

important?• Misinformation about obesity and health• Quackery and nostrums about diet and

exercise• What should we do

– Discover the cause of the obesity epidemic– Expertise on the President’s Council on

Fitness, Sports & Nutrition– Equal attention to diet and physical activity– K-12 education on behavioral change– Increase gasoline tax

President’s Councils• President’s Council of Economic Advisors

– Chair, Austan Goalsbee, on leave from the Univ of Chicago Booth School of Business

– Cecilia Rouse, Professor of Economics and Public Affairs, Princeton University

• President’s Council on Fitness, Sports & Nutrition– Co-Chair, Drew Brees, New Orleans Saints– Co-Chair, Dominique Dawes, Olympic gymnast

Outline• Activity/fitness, or obesity—which is most

important?• Misinformation about obesity and health• Quackery and nostrums about diet and

exercise• What should we do

– Discover the cause of the obesity epidemic– Expertise on the President’s Council on

Fitness, Sports & Nutrition– Equal attention to diet and physical activity– K-12 education on behavioral change– Increase gasoline tax

Liposuction can’t salvage Navy career-Washington Post, 1/31/11

• Mick Kruger, 38 year old master-at-arms– Never failed a fitness test– Routinely scores ‘excellent’ on 1.5 mile run– Has run one marathon and done 3 others on in-

line skates– Performance evaluations laud him for ‘superb

military performance’– 6’ 4” tall and 240 pounds– Neck=16” and Waist=40.5 inches– Navy is dismissing him because he is too fat– Who would you rather have defending you

against a bad guy?• Mick or ….

Outline• Activity/fitness, or obesity—which is most

important?

• Misinformation about obesity and health

• Quackery and nostrums about diet and exercise

• What should we do– Expertise on the President’s Council on

Fitness, Sports & Nutrition– Equal attention to diet and physical activity– K-12 education on behavioral change– Increase gasoline tax

Outline• Activity/fitness, or obesity—which is most

important?

• Misinformation about obesity and health

• Quackery and nostrums about diet and exercise

• What should we do– Expertise on the President’s Council on

Fitness, Sports & Nutrition– Equal attention to diet and physical activity– K-12 education on behavioral change– Increase gasoline tax

Thank you for your attention, and for allowing me to

express my provocative ideas