By Amby Burfoot
In a surprising article from a blue-chip panel of experts, the New England Journal of Medicine has shredded many of our most fervently held beliefs about obesity and weight loss. The article begins: “Passionate interests, the human tendency to seek explanations for observed phenomena, and everyday experience appear to contribute to strong convictions about obesity, despite the absence of supporting data.”
The rest of the “special article,” which deals with “myths,” “presumptions,” and “facts,” reads much like a feature story in your favourite health magazine. Only the conclusions are the opposite of what you have read and heard dozens of times. As briefly as possible:
1. Small changes can yield big results over time.
Fact: Nope, the actual changes may be only 20% of what you have been told.
2. Weight-loss goals must be realistic.
Fact: There’s little or no evidence for this.
3. Slow and steady wins the weight-loss race.
Fact: Little evidence. Might prove counterproductive.
4. Readiness to lose weight is important.
5. Phys ed classes help prevent obesity in kids.
Fact: Not proven by existing studies.
6. Breastfeeding infants protects them from obesity.
Fact: Nope. But it does have other important benefits.
7. Sex burns 100 to 300 calories.
Fact: Ha! Would you believe an average net burn of 14 calories?
PRESUMPTIONS (i.e., “widely accepted beliefs that have neither been proved nor disproved”)
1. Regular breakfast eating protects against obesity.
2. Childhood habits influence weight throughout life.
3. Eating more fruits and vegetables promotes weight loss.
4. Yo-yo dieting is associated with increased mortality.
5. Snacking leads to weight gain.
6. The “built environment” (sidewalks, parks, etc.) influences obesity rates.
1. Genetics are important, but are not your destiny. Personal choices can change your weight.
2. Diets “very effectively reduce weight,” but that doesn’t make dieting easy, guaranteed, or a long-term solution.
3. Exercise is healthy even if it doesn’t lead to weight loss. It can “mitigate” bad health effects of obesity.
4. Exercise “in a sufficient dose” can impact obesity. But this requires “a substantial quantity.”
5. Methods used to promote weight loss must be continued for “maintenance” of weight loss. Obesity requires “ongoing management.”
6. For children, at-home efforts with parents are crucial. School and other programs are not as effective as what can be achieved at home.
7. Use of provided meals and meal-replacement products is effective. These provide great structure.
8. “Some pharmaceutical agents” are helpful.
9. In appropriate cases, bariatric surgery is effective.