The Mayo Clinic Diet blog

Myths about weight loss

By Donald Hensrud, M.D. March 6, 2013

Recently, there was an article in a medical journal on myths about obesity, and there are many. Why is this?

Losing weight is challenging as everyone knows. And much more complex than it seems. It's much more than just eating less and exercising more. Because we don't understand weight loss well enough to be more successful, we search for explanations — and myths are created. Here are a few of these myths:

  • The reason why I weigh more is my metabolic rate is low. As people gain weight they increase not only body fat, but also some muscle to support that fat. Approximately 20-30 percent of excess weight is muscle. Muscle tissue burns calories, so the more muscle someone has, the greater the metabolic rate. So in general, the more someone weighs, the greater their metabolic rate. This doesn't include calories burned through physical activity.
  • The reason why I weigh more is my thyroid isn't working well. It's true that weight gain will occur in someone who has advanced hypothyroidism (low thyroid hormone). However, weight gain doesn't occur until someone has had hypothyroidism severely and for a long time. The vast majority of people whose thyroid gland isn't working properly have it discovered on a laboratory test when it's mild, long before it affects body weight. A simple blood test can tell if your thyroid gland is working properly.
  • Small changes in calorie intake will cause large changes in body weight over time. Occasionally, someone will state something such as: If you eat one less cookie each day, and that cookie contains 100 calories, then by doing the math you should lose more than 10 pounds after one year. Yet, why don't we know more people who've accomplished this? It's because as we lose weight, we burn less calories (our metabolic rate decreases as discussed above). This is also one of the reasons why we hit a plateau when we lose weight, and one of the complexities of weight loss.

There are many other weight loss myths. In our book, "The Mayo Clinic Diet," we have tried to take some of the myths and complexities out of weight loss. We try to explain things simply and provide a program that people can understand and follow. While weight loss is still challenging, we believe this can help.

March 06, 2013