Friday, August 7, 2009

Weight Loss and Exercise

I was directed to a new study written up in Time Magazine from "and sometimes tea" blog. This is interesting because the weight loss approach I took to lose 70+ pounds 9 years ago did not include exercise. In fact, the creator of the weight loss program said you don't need exercise to lose weight.

The Compensation Problem
Earlier this year, the peer-reviewed journal PLoS ONE — PLoS is the nonprofit Public Library of Science — published a remarkable study supervised by a colleague of Ravussin's, Dr. Timothy Church, who holds the rather grand title of chair in health wisdom at LSU. Church's team randomly assigned into four groups 464 overweight women who didn't regularly exercise. Women in three of the groups were asked to work out with a personal trainer for 72 min., 136 min., and 194 min. per week, respectively, for six months. Women in the fourth cluster, the control group, were told to maintain their usual physical-activity routines. All the women were asked not to change their dietary habits and to fill out monthly medical-symptom questionnaires.
The findings were surprising. On average, the women in all the groups, even the control group, lost weight, but the women who exercised — sweating it out with a trainer several days a week for six months — did not lose significantly more weight than the control subjects did. (The control-group women may have lost weight because they were filling out those regular health forms, which may have prompted them to consume fewer doughnuts.) Some of the women in each of the four groups actually gained weight, some more than 10 lb. each.

What's going on here? Church calls it compensation, but you and I might know it as the lip-licking anticipation of perfectly salted, golden-brown French fries after a hard trip to the gym. Whether because exercise made them hungry or because they wanted to reward themselves (or both), most of the women who exercised ate more than they did before they started the experiment. Or they compensated in another way, by moving around a lot less than usual after they got home.
The findings are important because the government and various medical organizations routinely prescribe more and more exercise for those who want to lose weight. In 2007 the American College of Sports Medicine and the American Heart Association issued new guidelines stating that "to lose weight ... 60 to 90 minutes of physical activity may be necessary." That's 60 to 90 minutes on most days of the week, a level that not only is unrealistic for those of us trying to keep or find a job but also could easily produce, on the basis of Church's data, ravenous compensatory eating.

It's true that after six months of working out, most of the exercisers in Church's study were able to trim their waistlines slightly — by about an inch. Even so, they lost no more overall body fat than the control group did. Why not?

Church, who is 41 and has lived in Baton Rouge for nearly three years, has a theory. "I see this anecdotally amongst, like, my wife's friends," he says. "They're like, 'Ah, I'm running an hour a day, and I'm not losing any weight.'" He asks them, "What are you doing after you run?" It turns out one group of friends was stopping at Starbucks for muffins afterward. Says Church: "I don't think most people would appreciate that, wow, you only burned 200 or 300 calories, which you're going to neutralize with just half that muffin."


Working out is hard to do with 6 kids under 12, including a newborn. I expect I will exercise, but it won't be hard core. It will probably a DVD or brisk walk. I understand the need to be healthy and that is reason to exercise. Exercising to lose weight, well, you just read it. It doesn't necessarily help.

By the way, I lost 4.5 lbs last week. That would be 12 lbs lost in 9 weeks. I need to slow down the weigh loss to 2 lbs a week. Losing more than 2 lbs a week can lead to toxins being released into breast milk and I don't want my desire to lose weight effect the Wee One.

1 comment:

  1. Hey, Cathie, you're right that 2 lbs a week is a safe amount to lose, but I would not worry too much about a large initial weight loss rate (and I would not raise my calories just yet to try to slow it down). In the first few weeks of a weight loss program it is very typical to lose a few extra pounds of water. I would give it 3 or 4 weeks at the rate you're at -- the rate of weight loss will likely slow down as the excess water is shed. As long as you continue to feel good, that is. If it were me I would stay the course at first.

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