Physical Inactivity Wim H.M. Saris NUTRIM University of Maastricht W.Saris@HB.Unimaas.nl 1 The Evolution of the Homo Sapiens 2 It s Calories that Counts Energy in *Portion size *High-fat foods *Energy dense *Low-fibre *Soft drinks Energy out *Cars *No heavy labour *Media (TV, PC) 3 The screen versions of these slides have full details of copyright and acknowledgements 1
Cheap Food Abundance Everywhere 4 5 Overview Trends in physical activity over the years Is inactivity causing the obesity problem? How much physical activity do we need? Conclusions 6 The screen versions of these slides have full details of copyright and acknowledgements 2
Prevention of Obesity by Physical Activity 7 Energy Balance and Secular Trends in Britain, 197-199 Food intake of 75 kcalday -1 since 197 Mean body weight of 2.5 kg Daily energy expenditure of 8 kcalday -1 James WPT. Int. J. Obesity, 1995 8 Trends in Leisure-Time Physical Activity Among Adults 18+ Years: BRFSS, 199-1998 Prevalence (%) 5 45 4 35 3 25 2 15 1 5 199 1998 199 1998 199 1998 o activity Insufficient activity Recommended activity Recommended levels = 3 minutes or more of moderate intensity activity >5 times/week or 2 minutes or more vigorous activity >3 times/week or both MMWR, 5(9); March 9, 21 9 The screen versions of these slides have full details of copyright and acknowledgements 3
Prev alence (%) 1 7 6 Prev alence (%) 5 4 3 2 1 11 45 4 35 3 25 2 15 1 5 Changes in Fat Intake Among US Adults 1977-78 1989-91 1994-96 Women Men Gender % 14 12 1 8 6 4 Age-Adjusted Trends in Obesity and Type 2 Diabetes Among US Adults 2 to 74 Years: 196-1994 2 Class III obesity 1955 196 1965 197 1975 198 1985 199 1995 2 Year Class I obesity Type 2 diabetes 65+ years Type 2 diabetes 45-65 years Class II obesity Enns CW et al., family economics and nutrition review, 1997 Flegal, et al., 1998; Harris M, NIDDK, 2; and Blair and Nichman, 21 12 The screen versions of these slides have full details of copyright and acknowledgements 4
Edible Fat Production from National Food Balance Sheets Availabilit y fat (g/day) 1965 1998 USE 117 143 +23% EU 117 149 +27% WHO 24 13 The American Paradox Unmasked (?) Goris et al., AJCN 2 14 Summary of Reported Leisure-Time Physical Activity Data Slightly increasing trend in reported leisure-time physical activity among adults Overall decreasing trend in daily activity levels among children 15 The screen versions of these slides have full details of copyright and acknowledgements 5
Components of Physical Activity Energy Expenditure DiPrietro 23 16 Trends in Automobile Use 1983 and 199 vehicle miles traveled per household- day increased by 29% 197 and 199 commuting to work by car increased by 11% 1995 only 16% of trips 1 mile are walked 1995 only.6% of trips 5 miles are biked US DHHS, 2 US Dept. Transportation, 1993, 1994 US Census, 2 17 Trends in Television Ownership and Remote Control Use: United States, 195-2 % of total households 1 9 8 7 6 5 4 3 2 1 195 1955 196 1965 197 1975 198 1985 199 1995 2 Year http://www.tvhistory,tv/tv-vcr-remote-cable-ownership.jpg TV set ownership remote control use 18 The screen versions of these slides have full details of copyright and acknowledgements 6
Computer and Internet Access in the Home: United States,1984-2 1 9 % of total households 8 7 6 5 4 3 2 1 1984 1989 1993 1997 1998 2 Year Computer Internet US Census Bureau, Current Population Survey, August, 2 19 Trends in Transportation to Work % of US workers 5 4.5 4 3.5 3 2.5 2 1.5 1.5 198 199 Walk to work 198 199 Bike to work US Dept Transportation, 1994 2 Trends in Riding Lawnmower Sales in the US: 1981-21 16 14 12 In thousands 1 8 6 4 2 Years 21 The screen versions of these slides have full details of copyright and acknowledgements 7
The Solution 22 Summary of the Available Indicators of Trends in Physical Activity All indicators of physical activity are pointing at a dramatic decrease over the last decades 23 Physical Activity and Weight Gain: Prospective Studies 11/12(13) studies allowing for the estimation of PAL show a protective effect 6/11 studies with more limited quantification of physical activity show a protective effect Rissanen 22 24 The screen versions of these slides have full details of copyright and acknowledgements 8
Prevalence of Obesity (%) by Physical Activity 5 4 Man 5. 42.41. % 3 2 1 14.2 11.2 6.7 24. 18. 14. 1. BMI >3 kg/m 2 1966-76, Finland (Rissanen et al.) BMI > 27 kg/m 2 1976-86, UK (Morris et al.) Overweight 199, Australia (Ball et al.) 25 Prevalence of Obesity (%) by Physical Activity 5 Woman 4 35. % 3 2 2 1.4 14.1 27. 2 2. 2. 1 8. BMI >3 kg/m2 1966-76, Finland (Rissanen et al.) Overweight 199, Australia (Ball et al.) 26 Physical Activity and Obesity in the European Union Martinez et al., IJO 1999 27 The screen versions of these slides have full details of copyright and acknowledgements 9
24-Month Increase in Energy Expenditure kcal. kg -1. day -1 * 1.2 Lifestyle Structured 1 *.8.6.4.2 * p <.1 within group Project active Dunn et al., JAMA 1999 28 24-Month Change in Weight and Percent Body Fat 1.5 Weight Percent body fat 1.5 Kilograms Percent -1.5 Lifestyle Structured * -1.5-3 * p <.1 within group Dunn et al., JAMA 1999 * - 3 Project active 29 Baseline Characteristics of 4-Examination Cohort, 375 Women and Men 13% women and 87% men Averag e ag e = 4.9 ± 7. years Averag e weig ht = 78.1 ± 13. kg Averag e follow- up = 5.2 ± 3.3 years 86% were non-smokers Averag e PAL = 1.46 ±.9 DiPietro et al., IJO 24; 28:1541 3 The screen versions of these slides have full details of copyright and acknowledgements 1
Weight Change Over Time by PAL Change Groups PAL change groups Low < 1.45; Mod = 1.45-1.6; Hi 1.6 79 78 Green lines are significantly different from the reference category (Low-low) Weight (kg) 77 76 75 Low-mod Low-high 74 Estimates adjusted for baseline weight, age, sex, height, and change in weight 73 2.5 5 7.5 1 Time (y) DiPietro et al., IJO 24; 28:1541 31 Dietary Guidelines for Americans 25* Physical Activity Recommendations To sustain weight loss in adulthood: participate in at least 6 to 9 minutes of daily moderate-intensity physical activity while not exceeding caloric intake requirements *www.health.gov/dietaryguidelines/dga25/document/ 32 Physical Activity and Energy Balance from an Evolutionary Prospective Are humans designed to live in modern society? Paleolitic ancestor Modern homo sapiens Best current estimate AEE 1Kcal 3Kcal PAL 2. 1.5-1.6 Subsistence efficiency 3:1 7:1 Boyd Eaton 22 33 The screen versions of these slides have full details of copyright and acknowledgements 11
How Much Is Enough to Prevent Unhealthy Weight Gain? Prospective DLW trials n = 2 R.C. DLW trials n = 34 85 Weight Regain Weight (kg) 8 75 7 65 6 PAL 1.55-1.75 PAL < 1.55 PAL > 1.75 55 3 6 9 12 Time (months) Mean body weights after weight loss of previousl y obese women, according to physical activity level (PAL, by DLW) after weight loss (at months) Schoeller et al., Am J Clin Nutr 1997; 66: 551-6 35 Free-Living Activity Energy Expenditure in Women Successful and Unsuccessful at Maintaining a Normal Body Weight Sedentar y women / 1 year follow-up Maintainers Gainers n = 27 n = 2 (BW gain 3%) (BW gain > 1%) BMI 23.1 BMI 24.4 BW -.5 kg BW +9.5 kg Weinsier et al., AJCN 22 36 The screen versions of these slides have full details of copyright and acknowledgements 12
Free-Living Activity Energy Expenditure in Women Successful and Unsuccessful at Maintaining a Normal Body Weight Maintainers Gainers Baseline Follow-up Baseline Follow-up PAL 1.68 1.73 1.55 1.6 Activ ity Kcal 72 679 49 467 Weinsier et al., AJCN 22 37 Prospective DLW Studies on Weight (Re-)Gain and PA Schoeller: additional 3.4 kcal/kg/d AEE needed to match maintai ner s 8 minutes moder ate activity Weinsier: additional 4. kcal/kg/d AEE needed to match maintai ner s 77 minutes moder ate activity 38 Exercise and Weight Regain in the National Registry of Weight Losers Estimated energy cost of exercise: 11-12 MJ per week Duration at 3 kj per minute: 5-6 minutes/week McGuire et al., IJO 1998, 22: 572-7 39 The screen versions of these slides have full details of copyright and acknowledgements 13
Prevention of Obesity by Physical Activity 4 How Much Physical Activity Is Enough to Prevent Unhealthy Weight Gain? IASO-stock conference Bangkok April 22 consensus statement There is compelli ng evidence that preventi on of weight regain in formerly obese individuals requires 6-9 minutes of moder ate intensity activity or lesser amounts of vigorous intensity activity; although definitive data are lacking, it seems likely that moderate intensity activity of approxi matel y 45 to 6 minutes per day, or 1.7 PAL, is required to prevent the transition to overweig ht or obesity; for children, even more activity time is recommended Saris et al., Obesity Rev., 23 41 Physical Activity Recommendations How much physical activity is required? for health benefits? 3 minutes/day to prevent weight gain? 6 minutes/day to prevent weigh regain in the formerly obese? 6-9 minutes/day Source: U.S. Dietary Guidelines 25 42 The screen versions of these slides have full details of copyright and acknowledgements 14
Energy Costs of Activities for 1 hr for 7 and 1 kg Person Type of physical activity 7 kg person 1 kg person Walking with the dog 21 3 kcal equal to ~6 steps Vigorous walking 35 5 kcal Bicycling for pleasure 28 4 kcal Bicycling moder ate effort 56 8 kcal Health club exercise 385 55 kcal Jogging 49 7 kcal Standing quietly 115 15 kcal Ainsworth et al., MSSE, 2 43 Does the Intensity of the Exercise Make a Difference? 44 Effect of ISO Energetic High or Low Intensity Exercise on 24-HR Substrate Metabolism Saris and Schrauwen IJO 23 45 The screen versions of these slides have full details of copyright and acknowledgements 15
Effect of ISO Energetic High or Low Intensity Exercise on 24-HR Substrate Metabolism Saris and Schrauwen IJO 22 46 Moderate Intensity Exercise 4.5-5.9 METs (4-64 y) (Surgeon General, 1996) 5 METs = 5 x 3.5 ml O 2. min -1. kg -1 = 17.5 ml O 2. min -1. kg -1 = 7% VO 2 max of average obese hard relative exercise intensity 47 Moderate Intensity Exercise for Obese = 45-6 % VO 2 max VO 2 max of average obese = 25 ml O 2.min -1.kg -1 or 7 METs 45-6 % VO 2max = 3-4 METs 48 The screen versions of these slides have full details of copyright and acknowledgements 16
Exercise Training and Compliance Training program: 4 weeks aim to run a half marathon Number of subjects 1 5 Success dropouts 18 2 22 Kg/m 2 24 26 Westerterp et al., BJN, 1992 49 Conclusions There is general consensus that increase in physical activity is a key component in body weight control However the existing guideline of 3 minutes a day of moderate activities is most probabl y not enough to prevent weight gain and certainly not regain 6 to 9 minutes seems to be more appropriate to prevent undesired weight gain and regain 5 51 The screen versions of these slides have full details of copyright and acknowledgements 17
52 The screen versions of these slides have full details of copyright and acknowledgements 18