1. Fitness or Obesity: What Is the Major Target for Intervention
Fitness or Obesity: What Is the Major Target for Intervention? German Diabetes Meeting Stuttgart, GERMANY May 15, 2010
Steven N. Blair
Professor
Departments of Exercise Science & Epidemiology/Biostatistics
University of South Carolina

2. Is too much attention given to obesity and not enough to physical activity?

3. Do We Have an Epidemic of Obesity?

4. Global Trends in Childhood Overweight
Reference: International Obesity Taskforce. Global trends in childhood overweight prevalence. Available at: Accessed 23 March 2010.
International Obesity Taskforce.

5. Global Trends in Childhood Overweight
Reference: International Obesity Taskforce. Global trends in childhood overweight prevalence. Available at: Accessed 23 March 2010.
International Obesity Taskforce.

6. Global Trends in Adult Obesity
Reference: International Obesity Taskforce. Trends in Adult Obesity Prevalence in Europe. Available at: Accessed 23 March 2010.
International Obesity Taskforce.

7. Causes of the Obesity Epidemic

8. It’s calories that count
Energy Out
Energy In
Portion size
High-fat foods
Energy dense
Low-fiber
Soft drinks
Snack foods
BMR
Thermic effect of food
Media (TV,PC)
Cars
No heavy labour
Exercise

9. Is the Average Total Daily Caloric Intake Increasing?

10. Trends in Energy Intake 1971 to 2000, Women, NHANES
Kcal/day
Source: MMWR Feb 6, 2004

11. 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

12. Trends in Chinese Energy Intake: Adults 18-45 years
Energy Intake (MJ)
Zhai F., Wang H., Du S., He Y., Wang Z., Ge K., Popkin B.M., Nutr Rev., 2009.

13. Trends in Energy Intake in Men from Tanushimaru , Japan
Energy Intake (kcal)
Adachi H., Hino A., J Epidemiol., 2005

14. Trends in Energy Expenditure

15. 1951 to 2004, Great Britain
Department of Transport, Scottish Executive and Welsh Assembly. (2005)

16. Trends in Riding Lawnmower Sales in the US: 1981-2001
In thousands
Slide from L DiPietro, Stock Conference, 2002

17. The 30-year trends of leisure time, occupational and commuting physical activity among Finnish adults
Borodulin, K. et al. Eur J Public Health : ; doi: /eurpub/ckm092

18. Occupational and Domestic PA trends in Chinese Adults, 1991-2000
Monda et al. Eur J Clin Nutr. 2008; 62:

19. Aerobics Center Longitudinal Study

20. Design of the ACLS 1970 More than 80,000 patients 2005
Cooper Clinic examinations--including
history and physical exam, clinical tests,
body composition, EBT, and CRF
Mortality surveillance to 2003
More than 4000 deaths
1982 ‘86 ‘90 ‘ ’99 ‘04
Mail-back surveys for case finding and
monitoring habits and other characteristics

21. All-Cause Death Rates by CRF Categories—3120 Women and 10 224 Men—ACLS
Blair SN. JAMA 1989

22. Amount of Specific Physical Activities for Moderately Fit Women and Men
Detailed physical activity assessments in women and men who also completed a maximal exercise test
Average min/week for the moderately fit who only reported each specific activity
Mean Min/week
N=3, ,444
Stofan JR et al. AJPH 1998; 88:1807

23. Fitness, Fatness, and Health

24. Interrelationships Among the Twin Epidemics of Obesity, Low Fitness, and Health
Obesity/Fat Distribution
Morbidity or
Mortality
No grants should be awarded
nor papers published
on fitness or obesity, and a health outcome unless both exposures are accurately measured and taken into account in analyses
Activity/Fitness

25. Cardiorespiratory Fitness, BMI, and Mortality, ACLS Men
25,389 men followed 8.5 years
673 deaths in 212,364 MY
Cardiorespiratory fitness assessed by a maximal exercise test
Calculated age-adjusted death rates for BMI and fitness categories
Barlow et al. Int J Obes 1995; 19:Suppl 4, S41-4

26. Age-Adjusted Death Rates by Fitness and BMI Categories
Deaths/10,000 MY
# deaths
Man-Yrs 25, , , , ,749 7, , ,240
Results held after adjustment for health status, smoking, glucose,
cholesterol, & BP
Barlow et al. Int J Obes 1995; 19:Suppl 4, S41-4

27. Criticisms of 1995 Int J Obes Study on Fitness & Fatness
“What a lot of rubbish”
Findings counter to “what we know”
Fit men with a high BMI were not fat, but had a high level of muscular development
Category of low fit men with a low BMI had an excess of smokers
Statistical adjustment for health status did not remove confounding by chronic disease

28. RR for All-cause and CVD Mortality in Fit and Unfit
ACLS Men by Body Fat Categories
Body Fat%
Body Fat%
All-cause Mortality
CVD Mortality
*adjusted for age, exam year, smoking, alcohol, & parental history
Lee CD, Blair SN, & Jackson AS. Am J Clin Nurt 1999; 69:373-80

29. Adjusted RR for All-Cause Mortality by Fitness and Waist Circumference
Waist circumference measurements in a subgroup 14,043 men
162 deaths in 78,008 man-years
RR adjusted for age, examination year, smoking habit, alcohol intake, and parental history of CHD
<87
87-<99
99
Lee CD, Blair SN, & Jackson AS. Am J Clin Nurt 1999; 69:373-80

30. Adjusted RR for All-Cause Mortality by Fitness and BMI, ACLS Women
*adj for age,
exam year,
smoking,
& health
status
Farrell et al. Obes Res. 2002; 10:

31. Fitness, Fatness, and Mortality in Men with Type 2 Diabetes

32. Low Fitness and Inactivity as Mortality Predictors in Men with Diabetes
Prospective study of 1,263 men, age=50±10 years
All men had type 2 diabetes at baseline
FPG 126 mg/dL
history of physician-diagnosed diabetes
taking anti-diabetic medication
Low fit=least fit 20% (42% of the men)
Inactive=no reported activity, past 3 months
Follow-up of 11.7 years, 14,777 man-years
180 deaths (92 CVD)
Wei et al. Ann Int Med 2000; 132:605-11

33. RR for Mortality by Fitness Level in Men with Type2 Diabetes
*Adjusted for age and examination year
Wei et al. Ann Int Med 2000; 132:605-11

34. RR* for All-Cause Mortality by Fitness and BMI Levels in Men with Type 2 Diabetes
*Adjusted for age and examination year
Wei et al. Ann Int Med 2000; 132:605-11

35. RR for All-Cause Mortality in Low Fit Men with Type 2 Diabetes, Adjusted for Age and Exam Year
Adj R R
95% CI >1.0 for all analyses
BMI High Chol Baseline CVD Known Diab
High BP Smoker Parental CVD
Reference Category (RR=1.0) is fit men
Wei et al. Ann Int Med 2000; 132:605-11

36. CVD Mortality Risk* by Fitness and BMI Categories, 2316 Men with Diabetes, 179 CVD Deaths
p for trend <0.0001
p for trend <0.0001
p for trend <0.002
Church TS et al. Arch Int Med
2005; 165:2114
*Adj for age and examination year

37. Survival curves by fitness levels within BMI categories in 831 men with type 2 diabetes, Veterans Exercise Testing Study ( )
≥5 METs
<5 METs
1.000
1.000
1.000
0.875
0.875
0.875
Survival
0.750
0.750
0.750
0.625
0.625
0.625
0.500
0.500
0.0
2.0
4.0
6.0
8.0
0.500
0.0
2.0
4.0
6.0
8.0
0.0
2.0
4.0
6.0
8.0
Follow-up (years)
Follow-up (years)
Follow-up (years)
Normal weight
(n = 78)
Overweight
(n = 330)
Obese
(n = 423)
McAuley et al. Diabetes Care 2007;30:
Slide from P McAuley

38. Attributable Fractions

39. Based on strength of association Prevalence of the condition
Attributable Fractions of Health Outcomes For Low Cardiorespiratory Fitness and Other Predictors, ACLS
Attributable fraction (%) is the estimated number of deaths due to a specific characteristic
Based on strength of association
Prevalence of the condition

40. Attributable Fractions for All-Cause Mortality
Blair S.N., Br J Sports Med., 2009

41. Relative Risks and Attributable Fractions of All-Cause and CVD Mortality by BMI Categories in Men
25,714 (1,025 all-cause and 439 CVD deaths) men aged ≥20 years in the ACLS.
10 years of follow-up.
Attributable fractions are adjusted for age, examination year, BMI, parental history of CVD, and each other item in the table.
Wei M. et al., JAMA, 1999

42. Relative Risks (RR) and Attributable Fractions (AF) of All-Cause Mortality by BMI Categories in Men
Normal
Overweight
Obese
RR (95% CI)
AF, %
Baseline CVD
2.3 ( ) 19
2.0 ( )
2.4 ( ) 27
Diabetes
1.3 ( ) 2
1.6 ( ) 6
1.5 ( ) 9
High cholesterol
1.0 ( )
1.3 ( ) 8
1.7 ( ) 18
Hypertension
1.5 ( ) 12
1.4 ( ) 13
1.1 ( ) 4
Current smoker
1.4 ( ) 7
1.5 ( )
Low fitness
1.6 ( ) 10
1.7 ( )
2.3 ( ) 44
Wei M. et al., JAMA, 1999

43. Summary
Inactivity and low fitness are major determinants of morbidity and mortality
Patients with type 2 diabetes should be strongly advised to become and stay physically active
More attention should be paid to regular physical activity in public health and clinical settings

44. Ranking of selected risk factors: 6 leading causes of death by income group, estimates for 2004
World Health Organization.
Percentage of total (total: 1.53 billion)
World Health Organization.

45. Final Message Focus on Healthful eating habits Fruits and vegetables
Whole grain
Regular physical activity
Three 10 minute walks/day

46. Thank you Questions?