"High Body Mass Index (BMI) Linked to Poor Health." Seen a headline like this one recently? They seem to be everywhere, and especially in school settings. BMI is essentially a measure of how much a person weighs for her or his height. Kids and adults are told to lower their BMI -- to slim down. It's true that many of us don't eat well to encourage health. But some take the mandate to lose weight as a license to practice dangerous eating patterns and ultimately develop eating disorders.
As with many health issues, the link between BMI and health is not as simple and predictable as we might think.
Physical Activity Lowers Heart Disease Risk in Those With High BMI
A study I recently discovered corroborates what others have begun to find -- that people can better their health, even if they aren't able to lose weight (lower their BMI). In this study, the health issue considered was coronary heart disease (CHD).Nearly 39,000 women were involved. It found that both BMI and level of physical activity affected the risk of heart disease. Specifically, high BMI increased the risk, but among those with high BMI, those who were more physically active had less risk than those who were inactive. Though risk of heart disease is just one element of health, it shows that BMI is not a complete way to measure health.
A Second Lesson: "Overweight" Does Not Mean "Lazy"
As I read fitness blogs and eating-related blogs around the web, I commonly find comments like, "Why is losing weight so hard? Just stop shoving jelly rolls into your mouth and get off the couch!" The implication is that if you're overweight, it's because you're not willing to invest the time, energy, and willpower to change.This study is a reminder that this isn't always true. The researchers explicitly separated BMI and physical activity in this study because they chose not to assume that high BMI implied low physical activity and vice versa. By avoiding this widely-held myth, they were able to come to a far more balanced picture of how we can pursue health.
The Scale Is Not Your Taskmaster
There are lots of reasons for us to avoid valuing ourselves according to weight. This study happens to give us a reason that is tangible. If you're working out and not losing weight, remember that muscle is more dense than fat. Measure your health in other ways -- improvement in endurance or strength, for example -- and your enjoyment of life can increase. It can happen without increasing your risk of developing or deepening an eating disorder.Source:
Weinstein AR, Sesso HD, Lee IM et al. The joint effects of physical activity and body mass index on coronary heart disease risk in women. Archives of Internal Medicine 168 (2008): 884-890.
