The big health and fitness news headline last month was this one: Study: Physical Inactivity Responsible for Twice as Many Deaths as Obesity.
Here’s an excerpt:
A study of 334,000 European men and women over 12 years concludes that physical inactivity is responsible for more than twice as many deaths as obesity, and that even small changes in activity levels can make a significant difference in life expectancy regardless of BMI.
In an article e-published ahead of print in the American Journal of Clinical Nutrition (.pdf), researchers compared individual BMI, waist circumference (WC), and self-reported physical activity (PA) levels with all-cause mortality data for 116,980 men and 217,181 women in Sweden, Denmark, The Netherlands, United Kingdom, France, Germany, Spain, Italy, and Greece. Individuals with baseline heart disease, cancer, or stroke history were excluded from the analysis, as were individuals who were in the top or bottom .5th percentile of the energy intake-to-estimated basal metabolic ratio rate. Researchers then created a 4-level activity designation based on daily kilojoule-per-kilogram rates: inactive (36 kJ/kg), moderately inactive (41 kJ/kg), moderately active (46 kJ/kg), and active (51 kJ/kg).
After adjusting for sex, educational level, and lifestyle (alcohol intake and smoking), researchers found that within all BMI groupings, mortality rates for moderately inactive individuals were 20%-30% lower than rates of inactive individuals. The reductions in mortality increased as activity levels increased, but only among normal and overweight individuals—rates for individuals with a BMI of 30 or higher did not drop when activity was recorded as more than “moderately inactive.”
In many ways, it’s not news. Activity matters more than weight, when it comes to health. Haven’t we known that for awhile?
Suppose you care about health, then
you might think we ought to focus on weight and activity. After all, they both matter. It’s just that activity matters more. (And actually you don’t have to care about health if you don’t want to. See Healthism, fitness and the politics of respectability.)
Regardless, I think it’s a mistake to link fitness and thinness together. For a lot of reasons.
1. You can’t lose weight anyway. Or at least, the odds of successfully doing it are very small. See past posts on the nearimpossibility of long term weight loss.
2. It sets people up for failure. Fat people start exercising. Measure progress on the scale. The scale doesn’t move and so they quit. That’s not good. Better to keep moving but why if weight is the measure of progress? Actually, here’s 13 non weight related reasons to eat well and move more.
3. Thin people feel falsely reassured. See this post for how linking thinness and fitness hurts thin people too.
4. Exercise doesn’t have that much to do with losing weight anyway. See this LifeHacker article.
Here’s more from the study:
Authors of the study believe that achieving a level of moderate inactivity among those who are currently inactive may be more easily reached than one might imagine. “This amount of energy expenditure can be achieved by a [physical activity energy expenditure] equivalent to 20 minutes of brisk walking per day, which is lower than the current PA recommendations for public health,” they write.
“Our results suggest that the influence of physical inactivity on mortality appears to be greater than that of high BMI and similar to that of high [waist circumference] in European men and women,” authors write. “From a public health perspective, it is therefore encouraging that our results suggest that small increases in PA in those who are currently categorized as inactive appear to be associated with significant reductions in all-case mortality at all levels of BMI and WC.”