Research paper finds obesity myths are still accepted at face value

Given the importance of tackling this modern epidemic, it's a shock how many unproven or simply wrong ideas still pass as science

PUBLISHED : Sunday, 24 February, 2013, 12:00am
UPDATED : Sunday, 24 February, 2013, 6:31am

What have you been told about combating obesity and weight gain? Does the following sound familiar?

  • Slow weight loss is better than quick loss.
  • Be realistic in setting weight loss goals. Ambitious goals have less likelihood of success.
  • Nothing helps weight loss like sex. Sexual intercourse burns a whopping 300 calories.

Well, they're all myths, littered throughout scientific and general literature, propped up as standard dogma, and widely echoed, even by experts. It turns out that what we know is far from what we learned.

In a study titled "Myths, Presumptions, and Facts about Obesity" published recently in the New England Journal of Medicine, the authors scoured popular media and scientific literature for obesity-related myths and presumptions and weighed them against scientifically proven facts. They found the following myths were especially prevalent:

Small, sustained changes in energy intake or expenditure produce large, long-term weight changes.
Fact: Unlike the piggy bank, little changes in caloric intake or burning do not build-up indefinitely. Our body mass is organic and simply cancels out the changes over time.

Setting realistic goals for weight loss is important, otherwise patients will become frustrated and lose less weight.
Fact: More challenging goals have been shown to be more effective.

Large, rapid weight loss is associated with poorer long-term weight-loss outcomes, as compared with slow, gradual weight loss.
Fact: People who lose weight quickly are actually more likely to weigh less after many years.

People can only lose weight when they are "ready" to do, so it is important to measure each patient's stage of diet readiness.
Fact: Unlike addiction treatment, mental readiness does not predict weight-loss results.

Physical-education classes, in their current form, play an important role in reducing or preventing childhood obesity.
Fact: Physical education classes, for all their benefits, do not include counteracting obesity.

Breast-feeding is protective against obesity.
Fact: Although breastfeeding has many advantages for mother and child, protection against obesity is not one of them.

Sexual activity burns 100 to 300 calories for each participant.
Fact: It's only 20 to 50 calories.These myths were gleaned from national health guidelines and studies from the 1960s. In the article, the authors discussed more recent studies that have debunked each myth.

As well, they also include six presumptions about weight loss that were defined as commonly espoused but unproven (nor debunked) theories; such as the idea that regularly eating breakfast protects against obesity. (The lead author has since initiated a randomised controlled trial to investigate this hypothesis.) Since the report was published, many obesity researchers have said this type of critical review as timely, as the field was simply swamped in a deluge of misinformation and unsubstantiated "facts" accrued over the decades with little effort to subject them to strict scientific scrutiny, as is done in other fields of medicine.

How did this happen? For one, obesity is a rather recent phenomenon that took hold in the developed world faster than science could keep up with it. We do know that it carries serious health consequences and, combined with cultural stigma, we seek urgent answers. To paraphrase Stalin, a lie repeated often enough becomes truth. Thus, well-meaning professionals and health-care agencies drew upon weak causal relationships and accepted them as facts. As well, we have an inherent tendency to embrace ideas that are desirable or simply make sense, despite being erroneous.

So what about some cold, solid, proven facts? The article advise the following:

  • Genetics do a play role in obesity;
  • Proper dieting is effective in losing weight; namely avoiding excess sugar, salt and fried foods;
  • Regular exercise can help manage weight and provide other health and longevity benefits;
  • Parents play a critical role in helping their overweight children slim down;
  • Meal replacements and meal plans help weight-loss efforts;
  • In selected patients, some weight-loss drugs and bariatric surgery helps.

It is important to understand that despite the title, the study was not a myth-busting exercise, but merely highlight that which has not been scientifically substantiated and to encourage the practice of evidence-based medicine. It is a wake-up call to medical scientists, doctors and the public at large.

Dr Ernie Yap practises internal medicine in the US