Doctors demolish slimming mythology

25 February 2013 - 02:36 By KATHARINE CHILD

Almost a third of South African women have been diagnosed as obese but many doctors, scientists and journalists believe in myths about how to lose weight.

In a New England Medical Journal article published in January titled Myths, Presumptions and Facts About Obesity, researchers identified seven myths and six false presumptions about weight loss that are often repeated in scientific and academic literature and the media.

After debunking the myths, the authors put forward weight-loss facts that they believe are "empirically proved".

Here are their facts about weight loss, and their advice on what to do and think if you need to shape up.

  • Genetic factors play a role in how fat you become but they are not destiny - the study debunked the idea that hereditary means that some people just had to be obese;
  • Dieting helps the obese lose weight: the only way to lose weight is to use more energy than you consume;
  • Exercise is important in mitigating the health risks linked to obesity even if it does not lead to weight loss. For slimming, exercise must be accompanied by reduction in food intake;
  • Structure in eating is more important than "variety, balance and moderation";
  • Exercise that helps with long-term weight maintenance has to include a "substantial quality of movement, not just mere participation";
  • Obesity is best managed as a chronic condition; continuous intervention is needed to maintain long-term weight loss;
  • Overweight children need to be helped to lose weight by their parents. Evidence showed that school-based interventions, such as physical education classes, were not effective whereas home-based interventions were.
  • In seriously obese people, surgery can help to save lives and reduce the risk of developing diabetes.

The researchers said they hope the facts will shape public health policy and doctors' advice instead of the widely held myths about weight loss.