August 03, 2008
Exercise Needed To Sustain Weight Loss?

The history of weight loss research has generally been that few weight losers keep the weight off. Well, in one group of overweight and obese women adding an additonal 5 hours per week of exercise and sustaining this kept off the lost weight.

In addition to limiting calories, overweight and obese women may need to exercise 55 minutes a day for five days per week to sustain a weight loss of 10 percent over two years, according to a report in the July 28 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.

More than 65 percent of U.S. adults are overweight, a public health concern, according to background information in the article. "Among obese adults, long-term weight loss and prevention of weight regain have been less than desired," the authors write. "Therefore, there is a need for more effective interventions." Current recommendations prescribe 30 minutes of moderate physical activity on most days of the week, for a total of 150 minutes per week. However, a growing consensus suggests that more exercise may be needed to enhance long-term weight loss.

To calculate the amount of exercise needed, John M. Jakicic, Ph.D., of the University of Pittsburgh, and colleagues enrolled 201 overweight and obese women in a weight loss intervention between 1999 and 2003. All the women were told to eat between 1,200 and 1,500 calories per day. They were then assigned to one of four groups based on physical activity amount (burning 1,000 calories vs. 2,000 calories per week) and intensity (moderate vs. vigorous). Group meetings focusing on strategies for modifying eating and exercise habits, as well telephone calls with the intervention team, also were conducted over the two-year period.

The only women who kept off all the lost weight burned more calories per week doing exercise. But they also continued to better follow weight loss diet advice.

After six months, women in all four groups had lost an average of 8 percent to 10 percent of their initial body weight. However, most were not able to sustain this weight loss. After two years the women's weight was an average of 5 percent lower than their initial weight, with no difference between groups.

The 24.6 percent of individuals who did maintain a loss of 10 percent or more over two years reported performing more physical activity (an average of 1,835 calories per week, or 275 minutes per week over the baseline level of activity) than those who lost less weight. They also completed more telephone calls with the intervention team, engaged in more eating behaviors recommended for weight control and had a lower intake of dietary fat.

I wonder if the problem of obesity is due to our appetites being evolutionarily tuned to eat for a higher average level of activity.

If we take pills that emulate exercise will this keep off the fat? More muscle would mean more calories burned per day since muscle just sitting there uses energy. So boosting our muscle mass would probably help keep the weight off. Exercise with more muscle mass would burn more calories per unit time.

I do not expect obesity to last as a problem for much longer than perhaps 15 years. Even if anti-obesity drugs take 10 years to develop we should know enough within 5 years what sorts of drugs to develop to boost muscle mass, reduce appetite, and increase breakdown of fat. The recent report about compounds that emulate the effects of exercise are an example of how fast our understanding of metabolism is advancing.

Share |      Randall Parker, 2008 August 03 05:42 PM  Aging Diet Weight Studies

Synergy6 said at August 3, 2008 5:58 PM:

I think you mean "an additional 5 hours per week", not "per day".

Alex Costa - said at August 3, 2008 8:10 PM:

That's the thing, diet doesn't work, you have to change your habits, when you lose weight with a quick fix, you don't fix the real problem which is bad habits.

peko said at August 4, 2008 5:11 AM:

change everywhere in text "calories" for " kilo calories", like in source of your source ;)

Bob Badour said at August 4, 2008 9:13 AM:

The diet used in the study as described in the article would cause muscle catabolism. It would also cause protein catabolism of other organs. I am not surprised increased exercise was required to keep the weight off. Actually, I am surprised the dieters did not return to a higher weight than where they started.

A ketogenic diet under a doctor's supervision would cause more rapid weight loss while sparing both muscle and other organs. I suspect such a diet would require less additional exercise to keep the weight off.

Brock said at August 4, 2008 10:25 AM:

What Bob said.

1. The high-carb/low-fat diet is pretty useless. Insulin regulates fat utilization, and carbs put it through the roof.
2. Low-to-medium intensity exercise can't hold a candle to short bursts of high-intensity exercise.

It's not as simply as calories in, calories out. Any research that isn't looking at gene expression and the hormonal causes of fat accumulation are dead ends.

sub said at August 4, 2008 10:31 AM:

The problem with buidling up a lot of muscle mass is that you need to exercise regularly, else you will not be able to maintain the same mass over time. Your metabolism will change when you gain muscle mass, meaning that you will burn more calories at a faster rate but also that you need to feed your muscle high grade protein so that the same mass do not decrease. Lab tests with obese mice show many positive results with a pure protein diet and regular workout - longevity, higher performance and so on.

Google for AICAR perhaps?,0,1750044.story

P.S The US will have a huge problem with an obese population becoming diabetic the coming years = cost.

steveSC said at August 4, 2008 11:05 AM:

This study shows nothing. The key sentence: "After two years the women's weight was an average of 5 percent lower than their initial weight, with no difference between groups."

"No difference between groups" means that instructing women to exercise more (in amount or intensity) does NOTHING. In an effort to rescue something out of the study (and get a publication), the authors retroactively looked at the data and... ta da! found that people who are more motivated keep the weight off better than those who are less motivated!

Rusty Rosenberger said at January 1, 2009 1:45 PM:

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"Boxercise" & "BodyBoxing/SafeBoxing Fitness Programs,
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Please consider using me and my safe boxing fitness programs as a trainer/teacher, on your very popular show. Any over weight and out of shape individual, will feel and begin to visibly see results in just 3-10 minute training sessions, completed in a weeks time, guaranteed.

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Lorenzo Stone said at October 22, 2009 11:54 PM:

Bad Habits Die hard! Exercise is just a fraction of weight loss, i believe that you are what you eat. Eating alkaline based foods regulary such as fresh raw greens will really help you lose weight. Discipline in eating is very important. Drinking lots of water regularly help the acid in our body to flush off our system. much acid in our body makes us feel week and well have a hard time doing exercise because it lodges to the muscles.. got this from christopher guerriero.

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