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LIFELONG HEALTH- Myths About Obesity Rest on Slim Evidence PDF Print E-mail
Written by Dr. David Lipschitz   
Thursday, 28 February 2013 05:31

Much of what we believe about obesity may be incorrect.

The New England Journal of Medicine recently published "Myths, Presumptions and Facts About Obesity," a paper from scientists at nutritional centers in the United States and abroad. They suggest that many common beliefs regarding obesity are not supported by scientific evidence (they are presumptions) or that information suggests the beliefs to be incorrect (myths).

This paper raises serious questions about our understanding of obesity.

Here are beliefs the authors identify as myths.

Myth: Reducing calorie intake or increasing exercise over prolonged periods of time leads to significant weight loss, so slightly reducing food intake while adding moderate exercise can lead to an annual weight loss of 10 pounds. Research shows that for most people, the loss is more like 2 pounds annually.

Myth: It is important to set realistic weight loss goals, and failure to do so leads to frustration, limiting weight loss. New research indicates that the more ambitious the weight loss goals, the better.

Myth: Rapid weight loss is less likely to succeed in the long term compared with slow, gradual weight loss. Remarkably, research indicates that rapid initial weight loss leads to a higher chance of success.

Myth: To be successful, someone must be ready and committed to weight loss. In fact, initial attitude about weight loss does not appear to predict success.

Myth: Physical education programs help to prevent childhood obesity. Sadly, a number of research studies have shown that frequent supervised exercise programs at school do not affect weight.

Myth: Being breastfed reduces the lifetime risk of obesity. A recent analysis of World Health Organization information shows this is not true.

Myth: Increased sexual activity helps weight loss. It was said that sexual activity expends up to 300 calories, but research has shown that the actual calories expended are typically 3.5 per minute. And here are beliefs not supported by scientific evidence (presumptions).

1. Eating a big breakfast helps prevent weight gain by reducing hunger later in the day. One study stated that breakfast habits showed no impact on weight, while another showed some benefit.

2. Eating more fruits and vegetables helps weight loss. While they are healthy for you, studies show that merely eating these foods without making other behavioral changes may not promote weight loss.

3. Early childhood habits in regard to exercise and diet affect weight in later life. Evidence suggests that genetic factors, not habits, affect weight in later life.

4. Weight cycling increases the risk of dying. It is better to maintain a stable weight than to lose and gain weight repetitively.

Although there is some truth to the observation that weight cyclers (yo-yo dieters) often have health problems, studies have not been done that prove cause and effect, and many experts question the validity of this belief.

5. Snacking contributes to obesity. Here as many studies show weight loss as show gain. 6. Living in a community with great parks and sidewalks promotes weight loss. There is no consistent evidence from the observational studies that have been done that shows where you live affects obesity risk.

The authors listed some beliefs that have been supported by scientific evidence.

While genetic factors affect weight, their effect can be modified by changes in diet, health and exercise.

Going on a specific recommended diet effectively leads to weight loss but rarely succeeds in the long term.

While exercise alone may not lead to weight loss, regardless of your size, it is good for your health, and exercise in sufficient amount (that is vigorous) helps promote weight loss.

Developing and maintaining healthy habits promotes and, more importantly, maintains weight loss.

For overweight children, involving the parents in a plan is the most critical factor leading to weight loss. Providing balanced meals or using meal replacement products does appear to assist in long-term weight loss by promoting better structure and meal habits. And finally, use of some pharmaceutical pills can assist in losing and maintaining weight, and bariatric surgery is very effective in overcoming morbid obesity.

What conclusions can be drawn from this information? If you are morbidly obese, a medically supervised program that leads to rapid weight loss may prove effective if accompanied by appropriate lifestyle changes. If all else fails, consider gastric bypass (bariatric) surgery.

If moderate weight loss is needed, learn how to eat well. That may require joining an appropriate weight loss program (for example, Weight Watchers).

Set ambitious weight-loss goals, and exercise as much as possible. To be effective, these habits must become lifelong and enjoyable.

Dr. David Lipschitz is the author of the book "Breaking the Rules of Aging." To find out more about Dr. David Lipschitz visit

Last Updated on Thursday, 28 February 2013 05:33