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Weight Loss & Obesity: 7 Myths & 9 Facts

6 Presumptions

The article also explores six "presumptions," or widely accepted beliefs that are neither proven nor disproven. They are:

Eating breakfast prevents obesity. 

Actually, two studies showed no effect of eating vs. skipping breakfast.

Childhood is the time to learn to exercise and eat well.

While it certainly can't hurt, there's no rigorous evidence to support it.

Adding fruits and vegetables to the diet results in weight loss. 

Adding more calories of any type without making any other changes is likely to cause weight gain. Eating fruits and vegetables is healthful, however.   

Yo-yo dieting increases your risk of death.

While some studies have shown a debatable link, none have actually proven a cause and effect.

Snacking contributes to weight gain and obesity.

There's no solid evidence to support this belief.

More parks and sidewalks means less obesity.

Again, the evidence just isn't there.

9 Facts

Finally, the authors offer nine facts about obesity and weight loss that are supported by evidence.

"The myths and presumptions about obesity that we have discussed are just a sampling of the numerous unsupported beliefs held by many people, including academics, regulators, and journalists, as well as the general public. Yet there are facts about obesity of which we may be reasonably certain -- facts that are useful today," Casazza says.

Here they are:

  • Your genes are not your destiny. Moderate environmental changes can promote as much weight loss as even the best weight-loss drugs.
  • Diets do produce weight loss, but attempting to diet and telling someone to diet are not necessarily the same thing.
  • Even without weight loss, physical activity improves health.
  • Physical activity or exercise in the right amounts does help people lose weight.
  • Continuation of conditions that promote weight loss helps people keep the weight off. Think of obesity as a chronic condition.
  • For overweight children, involving the family and home environment in weight-loss efforts is ideal.
  • Providing actual meals or meal replacements works better for weight loss than does general advice about food choices.
  • Weight-loss drugs can help some people lose weight.
  • Bariatric surgery can help achieve long-term weight loss in some people.

Several of the researchers -- not including Casazza -- disclosed a long list of financial relationships with a wide range of groups, from Coca-Cola to Kraft Foods, to pharmaceutical companies such as Vivus and Arena -- companies that make two weight-loss drugs recently approved by the FDA. The study was supported in part by the National Institutes of Health.

Regardless, the researchers write that what they included in their article "are just a sampling of the numerous unsupported beliefs" out there. It is important, they say, to banish myths with "scientific method and logical thinking."

“As scientists, we have the responsibility to present the evidence as it exists without inflating ideas and contributing to popular misconceptions. As a registered dietitian, I feel that providing evidence-based statements about weight loss is essential,” Casazza says.


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