Professor Talk: Common Myths About Weight Loss Debunked

If you believe having sex or breastfeeding are bona fide ways to keep the extra pounds off, you may want to check your sources. 

Montclair State University’s Diana Thomas, involved in the Center for Quantitative Obesity Research at the university, recently participated in a study to debunk common myths about weight loss, which appeared in the New England Journal of Medicine. 

The team of researchers, led by David Allison, Ph.D., associate dean for science in the School of Public Health at the University of Alabama at Birmingham, quashed the following myths: 

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. This is because changes in body mass eventually cancel out the change in calorie intake or burning.

Myth 2: Setting realistic weight loss goals will make you less likely to give up.  

Fact: Some data suggest that people do better with more ambitious goals. 

Myth 3: Gradually losing weight is better than quickly lost pounds, because 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, and therefore healthcare professionals 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 or 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 calories for each person involved.  

Fact: It may be closer to one twentieth of that for the average man, and only slightly more than sitting on the couch. 

The study also found six more common beliefs that seem to be wrong, although more research is needed. These beliefs include finding no effective evidence to suggest that eating regularly throughout the day versus skipping breakfast will contribute to losing weight.

Click here to be brought to the study.

Your Montclair Patch editor recently spoke with Thomas about the study. 

Patch: How did the idea for this study come about? 

Thomas: It was about a year ago when Montclair State was contacted by David Allison, the lead researcher for the project. We discussed this idea that there are beliefs held not just by the public but also by scientists, despite a lack of evidence or really sound evidence demonstrating otherwise.

So we wondered why these beliefs were so pervasive. 

Patch: Are you saying that dietitians, professionals and people who get paid for their opinions about weight loss are getting this wrong?

Thomas: Absolutely.

If you look at the first myth, that small changes in calorie intake leads to weight loss, it is up on the United State’s Surgeon General’s website. This rule was developed in the 1950s, and the rule has never been tested and was actually recently debunked in 2011. 

This idea is also endorsed by weight loss programs, researchers, various websites, textbooks, downloadable apps, and is even being taught by Montclair State’s Nutrition Department!

Patch: Is there one myth far and above the most widely held?

Thomas: The first myth is probably the most prevalent. It seems to be ingrained everywhere.

Patch: How were these myths debunked?

Thomas: For each of these ideas about weight loss, we looked at them scientifically. We devised an experiment to really test these ideas.  

The myth about breast feeding and weight loss, for example, needs to take into account innumerable different things, such as economic levels. A study was done comparing two siblings, one who was breast fed and one who was not, and years later there was no evidence suggesting one's weight is affected by being breast fed. 

Patch: Are people’s belief in how to lose weight easily changed or corrected?

Thomas: No, people’s belief in these myths and many more are very strong. This is the one place that science has trouble. The science my by very rigorous and carefully done, but the science for some reason still has trouble swaying an individual’s belief. 

Patch: So what can people do to maintain a healthy weight? 

Thomas: We offer many suggestions in the study. Another great place for more information is the National Weight Control Registry, which uses real people’s experience and keeps tract of the methods that contributed to their weight loss.  

For example, 89 percent of the people in that national registry lost weight with a combination of diet and exercise. While hardly anyone has lost weight and maintained it with either diet or exercise alone.  

Thomas has been at the university since 2000. Her research interests include developing, validating, and applying mathematical models to obesity related issues. Thomas has developed body composition models for use within energy balance equations that predict changes in weight in response to altered diet, increased exercise energy expenditure, and pregnancy.