Common beliefs about obesity and weight loss found to be myths

Think going to gym class drives weight loss, or that breastfeeding protects a child from obesity? Think again, because these are among seven popular myths about obesity myths, according to an international team of researchers.

The seven popular but largely inaccurate beliefs, which lead to poor policy decisions, inaccurate public-health recommendations and wasted resources, were identified by the team led by David Allison, associate dean for science in the School of Public Health at the University of Alabama at Birmingham.

Here are the seven 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. 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, do health-care 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 and preventing childhood obesity.
Fact: Physical education, as typically provided, does not appear to counter obesity.

• Myth 6: Breastfeeding protects children 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.

The research team also defined six “presumptions” that are generally held to be true even though more studies are needed before conclusions can be drawn, such as the idea that regularly eating versus skipping breakfast contributes to weight loss. Studies show it has no effect.

The same goes for the idea that eating vegetables by itself brings about weight loss, or that snacking packs on the pounds. According to Allison and colleagues, these hypotheses have not been shown to be true, and some data suggest they may be false.

The researchers also identified nine research-proven facts about weight loss. For example, weight-loss programs for overweight children that involve parents and the child’s home achieve better results than programs that take place solely in schools or other settings.

Also, many studies show that while genetic factors play a large role in obesity, “Heritability is not destiny.” Realistic changes to lifestyle and environment can, on average, bring about as much weight loss as treatment with the most effective weight-loss drugs on the market. (Read more)