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Weight Loss Myths

As with many aspects of health and medicine, there are a variety of myths and presumptions that have been espoused regarding weight loss over the years.  In 2013, The New England Journal of Medicine published an article discussing obesity related myths, presumptions and evidence supported facts that even some physicians might find surprising.  

We asked Richard Siegel, MD, a consulting endocrinologist with the Weight and Wellness Center at Tufts Medical Center to give some perspective on these common myths.

Myth number 1: Small sustained changes in energy intake or expenditure will produce large, long-term weight changes.

Comment:  For the last 50 years or so, the popular belief has been that in order to lose 1 pound, or gain one pound, you would need to decrease or increase your caloric intake or your physical activity by 3500 kcals. However, we now know that as your weight changes, so does the energy requirements of the body. So if you start walking one mile a day, you may initially lose a little bit of weight, but if you continue to walk the same amount every day, your body adjusts and you are not likely to lose significant weight long term.

Myth number 2: Setting realistic goals for weight loss is important, because otherwise patients will become frustrated and lose less weight.

Comment: While this sounds reasonable in theory, there is no data to back it up.  In fact, a number of studies suggest that more ambitious weight loss goals may sometimes be associated with better weight loss outcomes.

Myth number 3: Large, rapid weight loss is associated with poorer long-term weight-loss outcomes, as compared with slow, gradual weight loss.

Comment: Greater initial weight loss has been associated with lower body weight at the end of long term follow-up in weight loss clinical trials. This does not mean starving yourself or following a fad diet is a healthy way to lose weight. While it is not clear why some people lose more weight initially than others, the authors note that any suggestion that they slow down might interfere with successful weight loss.

Myth number 4: It is important to assess the stage of change or diet readiness in order to help patients who request weight-loss treatment.

Comment: If you’ve tried to lose weight before, you may have been asked by a doctor or nutritionist – are you ready to make the commitment?  Researchers have found the degree of readiness does not always predict the amount of weight loss. This is true for those signed up for both medical and surgical weight loss. Bottom line – if you are overweight, there is no time like the present to begin your effort to slim down.

Myth number 5: Physical-education classes, in their current form, play an important role in reducing or preventing childhood obesity.

Comment:  Many schools across the country are slimming down their physical education programs to make room for more academic time. While fresh air and exercise may have many benefits for children, the research suggests that gym classes, in their current form, do not help kids achieve a healthy weight.

Myth number 6: Breast-feeding is protective against obesity.

Comment: While there are many potential benefits of breastfeeding for mother and infant, the authors of the study write that the best research does not suggest an anti-obesity effect for children later in childhood.

Myth number 7: A bout of sexual activity burns 100 to 300 kcal for each participant.

Comment:  Many of us have been told that sexual activity is an aerobic activity and great calorie burner. But according to this research, it’s not as effective as we might like. A better estimate of energy expenditure during sexual intercourse appears to be closer to only 20 kcal. Of course, someone watching television would have expended just one-third that much, so the result is better than being sedentary but hardly will help you lose weight.

The article also suggested a number of evidence-based facts about obesity:

  • Although genetic factors play a large role, heritability is not destiny; calculations show that moderate environmental changes can promote as much weight loss as the most efficacious pharmaceutical agents available.
  • Diets very effectively reduce weight, but trying to go on a diet or recommending that someone go on a diet generally does not work well in the long term.
  • Regardless of body weight or weight loss, an increased level of exercise increases health.
  • Physical activity or exercise in a sufficient dose aids in long-term weight maintenance.
  • Continuation of conditions that promote weight loss promotes maintenance of lower weight.
  • For overweight children, programs that involve the parents and the home setting promote greater weight loss or maintenance.
  • Provision of meals and use of meal-replacement products promote greater weight loss.
  • Some pharmaceutical agents can help patients achieve clinically meaningful weight loss and maintain the reduction as long as the agents continue to be used.
  • In appropriate patients, bariatric surgery results in long-term weight loss and reductions in the rate of incident diabetes and mortality.

“What this research shows us is that we are still learning about the best ways to lose weight and keep it off,” said Dr. Siegel. “What is certain is there is no one size fits all approach. Learn what works for you and stick with it.”

Posted 1/11/17 

The above content is provided for educational purposes by Tufts Medical Center. It is free for educational use. For information about your own health, contact your physician.