The United States faces a fitness paradox right now. If people are exercising more, as they claim to be, then why is it not doing anything for their waistlines? Obesity continues to affect one-third of Americans, despite increased levels of exercise.
In order to find out how much Americans are exercising, the University of Washington conducted a study based on thousands of responses collected by the Centers for Disease Control and Prevention. The number of women who exercise ‘sufficiently’ rose from 50.7 percent in 2001 to 59.2 percent in 2011. For men, it rose from 59.4 percent to 61.3 percent. And yet, for every percentage point increase in exercise, there was only a 0.11 percent lower likelihood of obesity, and obesity rates overall have risen during the decade of study. Clearly something isn’t adding up.
Perhaps the problem lies in the definition of ‘sufficient exercise.’ The study stated that “150 minutes of moderate activity per week or 75 minutes of vigorous activity” were considered sufficient. Five 30-minute walks (for example, walking 15 minutes to and from work each day) is beneficial, but it’s likely not intense enough to melt away extra pounds. The study also relied on self-reporting, which can be an unreliable source of information. A person may think they’re exercising vigorously when they’re not.
More important, though, is the question of diet. I’m going to go out on a limb here and say that exercise is almost pointless if a person doesn’t eat nutritiously. Engaging in 75 minutes of vigorous exercise each week will accomplish little if someone continues to eat large quantities of greasy, salty processed food, high-glycemic carbohydrates, and sugar. It’s impossible to isolate exercise from diet when trying to lose weight, and inevitably there comes a point when a poor diet will inhibit progress, no matter how much a person exercises.
The University of Washington study agrees that problems with diet need to be addressed in order for exercise to fully benefit people:
“Our study showed that increased physical activity alone has a small impact on obesity prevalence at the county level in the U.S. Other changes such as reduction in caloric intake are likely needed to curb the obesity epidemic and its burden.”
I don’t think the number of calories matters so much as the kind of calories, because not all calories are created equal. If more people adjusted their diets to focus on healthy-sized portions of fresh vegetables and fruit, whole grains, lean meats or fish, nuts and seeds, I suspect obesity rates would plummet in the U.S., even if exercise rates didn't increase significantly. Like it or not, it all starts with nutrition.