Some Truths about Obesity

As individuals gain weight, many myths and presumptions about obesity have also grown – despite the lack of objective evidence. A New England Journal of Medicine article (“Myths, Presumptions, and Facts about Obesity”) helped separate facts from these many myths and presumptions. Our nation has the distinction of being the second fattest nation in the history of the world. Nauru is the fattest.

First, let’s agree on some definitions. Myths are beliefs held to be true, despite substantial refuting evidence. Presumptions are also beliefs thought to be true, but lack convincing evidence to confirm or deny their validity. Facts are backed by sufficient evidence, so they can be considered empirically true.

Obviously, having facts are best. Unfortunately, we cannot always obtain absolute scientific confirmation to get to the “fact” stage because we sometimes have inadequate information. Understanding this limitation is acceptable so long as it is recognized as such and not misrepresented. In other words, using the scientific method is optimal but not always possible. For instance, in obesity research, certain types of studies would not be possible or ethical. Overfeeding one group of human subjects and starving another is not ethical or possible. Historically, due to outside environmental factors such as wars and famines, observational studies have been completed and are considered valid scientifically.

First, let’s start with seven myths—surprisingly none of which have any validity, and all have been proven wrong:

1. Small, sustained changes in energy intake will produce long-term weight loss.
2. Setting realistic goals is important because otherwise people will become frustrated and lose less weight.
3. Large, rapid weight loss is associated with poorer long-term weight outcomes than slow, gradual weight loss.
4. Assessing the stage of change or diet readiness is important in helping patients who seek weight-loss treatment.
5. Physical-education classes in their current format play an important role in preventing or reducing childhood obesity.
6. Breast feeding is protective against obesity.
7. A session of sexual activity burns 100 to 300 kcal for each person involved.

Next, six presumptions—thought to be true but no convincing scientific evidence.

1. Daily consumption of breakfast (vs. skipping) is protective against obesity.
2. Early childhood is the period during which we learn exercise and eating habits that influence our weight throughout life.
3. Eating more fruits and vegetables will result in weight loss or less weight gain, regardless of other factors.
4. Weight cycling (i.e. yo-yo dieting) is associated with increased mortality.
5. Snacking contributes to weight gain and obesity.
6. The environment, in terms of sidewalk and park availability, influences obesity.

Finally, and most importantly, nine facts confirmed scientifically:

1. Although genetic factors play a large role, heritability is not destiny. You can change your environment.
2. Diets are very effective but hard to do in the long term.
3. Regardless of body weight or weight loss, an increase in exercise increases good health.
4. Physical activity or exercise in a sufficient dose aid in long term weight maintenance.
5. Continuance of conditions that promote weight loss promotes maintenance of lower weights.
6. For overweight children, programs that involve the parents and the home setting promote greater weight loss.
7. Provision of meals and use of meal-replacement products promote greater weight loss.
8. Some pharmaceutical agents can help meaningful weight loss and maintain the loss if these agents are used.
9. In appropriate patients, bariatric surgery can be effective and lower morbidity and mortality.

So much of what is believed true according to “pop culture,” is not only false but adds confusion and frustration. We need scientifically-proven methods to follow in order to improve our individual health, our community’s quality of life and most importantly the next generation’s ability to thrive in an increasingly competitive world.

The bottom line: exercise works long term—and diets are hard to do long term. Hope this helps all of us improve our health. See you at the gym?