(This is part 3 of a 12 part series to provide you with some helpful health and fitness tips over the holiday season)
Most of us eat more when we exercise, and though it may be just a few extra bites a day, the result is weight gain. People hoping to lose weight with exercise often wind up being their own worst enemies, according to the latest, large-scale study of workouts, weight loss and their frustrating interaction. The study, which carefully tracked how much people ate and moved after starting to exercise, found that many of them failed to lose or even gained weight while exercising, because they also reflexively changed their lives in other, subtle ways. But a few people in the study did drop pounds, and their success could have lessons for the rest of us.
Is Exercise Effective Enough?
In a perfect universe, exercise would make us thin. Physical activity consumes calories, and if we burn calories without replacing them or reducing our overall energy expenditure, we enter negative energy balance. In that condition, we utilize our internal energy stores, which most of us would call our flab, and shed weight. But human metabolisms are not always just and cogent, and multiple past studies have shown that most men and women who begin new exercise routines drop only about 30 percent or 40 percent as much weight as would be expected, given how many additional calories they are expending with exercise. Why exercise underwhelms for weight reduction remains an open question, though. Scientists studying the issue agree that most of us compensate for the calories lost to exercise by eating more, moving less, or both. Our resting metabolic rates may also decline if we start to lose pounds. All of this shifts us back toward positive energy balance, otherwise known as weight gain. It has not been clear, however, whether we tend primarily to overeat or under-move as compensation, and the issue matters. To avoid compensating, we need to know how we are doing it.
How Are We Doing It?
One of the main complaints about exercise is that it can make you hungry and cause you to eat more. It’s also been suggested that exercise may make you overestimate the number of calories you’ve burned and “reward” yourself with food. This can prevent weight loss and even lead to weight gain. Although it doesn’t apply to everyone, studies show that some people do eat more after working out, which can prevent them from losing weight. Exercise may influence the hormone ghrelin. Ghrelin is also known as “the hunger hormone” because of the way it drives your appetite. Interestingly, studies show that appetite is suppressed after intense exercise. This is known as “exercise anorexia” and seems tied to a decrease in ghrelin. However, ghrelin levels go back to normal after around half an hour. So although there is a link between appetite and ghrelin, it doesn’t seem to influence how much you actually eat. Studies on calorie intake after exercise are mixed. It’s now recognized that both appetite and food intake after exercise can vary between people. For example, women have been shown to be hungrier after working out than men, and leaner people may become less hungry than obese people So, if you are hoping to lose weight with exercise, pay close attention to what you eat and not quit or blame the exercise.
Til next time, train smart, eat well, and be better.
See you tomorrow for Day 4 of the 12 Days of Fitness
Just in case, here’s what you might have missed: