Hercules and the Hydra

Obesity Myths Busted in the New England Journal of Medicine

A distinguished team of obesity experts led by David Allison at the University of Alabama at Birmingham has published a peer-reviewed challenge to some cherished conventional wisdom about obesity. This is conventional wisdom that they find lacks real evidence to support it. Calling out seven “obesity myths,” Allison said that “false and scientifically unsupported beliefs about obesity are pervasive.”

Underscoring the importance of separating facts from presumptions and myths, the authors commented, “Unsupported beliefs may yield poorly informed policy decisions, inaccurate clinical and public health recommendations, and an unproductive allocation of research resources and may divert attention away from useful, evidence-based information.” The paper also identifies six presumptions that may or may not be true, and nine facts that are well established.

Here are the myths. Prepare to let them go.

  • Myth 1: Small, sustained changes in how many calories we take in or burn will accumulate to produce large weight changes over the long term. Fact: Small changes in calorie intake or expenditure do not accumulate indefinitely. Changes in body mass eventually cancel out the change in calorie intake or burning.
  • ·Myth 2: Setting realistic goals in obesity treatment is important. Otherwise patients become frustrated and lose less weight. Fact: Some data suggest that people do better with more ambitious goals.
  • Myth 3: Gradually losing weight is better than quickly losing pounds. Quick weight losses are more likely to be regained. Fact: People who lose more weight rapidly are more likely to weigh less, even after several years.
  • Myth 4: Patients who feel “ready” to lose weight are more likely to make the required lifestyle changes. Health-care professionals therefore need to measure each patient’s diet readiness. Fact: Among those who seek weight-loss treatment, evidence suggests that assessing readiness neither predicts weight loss nor helps to make it happen.
  • Myth 5: Physical education classes, in their current form, play an important role in reducing and preventing childhood obesity. Fact: Physical education, as typically provided, does not appear to counter obesity.
  • Myth 6: Breastfeeding protects the breastfed offspring against future obesity. Fact: Breastfeeding has many benefits for mother and child, but the data do not show that it protects against obesity.
  • Myth 7: One episode of sex can burn up to 300 Kcals per person. Fact: It may be closer to one-twentieth of that on average, and not much more than sitting on the couch.

No doubt this myth-busting will stir some controversy. Allison and his colleagues have carefully chosen beliefs that many people concerned about health and obesity hold dear. But their analysis may be hard to dispute.

Click here to access the article in the New England Journal of Medicine.

Hercules and the Hydra by Antonio del Pollaiolo / Wikipedia