In their seemingly never-ending quest to find a “magic pill” to shed unwanted pounds, Americans spend more than $2 billion — yes, that’s billion with a “b” — on weight loss supplements every year.

While this consumer behavior may be great news for those who manufacture and market the substances, several health and fitness experts have called the effectiveness of these supplements into question.

To put it another (simpler) way: Research indicates that the stuff doesn’t work.

The most recent piece of evidence against the effectiveness of weight loss supplements is a study by a nutrition expert at Oregon State University. According to a March 6 ScienceDaily post, OSU Professor Melinda Manore evaluated the following four types of supplements:

  • Products such as chitosan that block absorption of fat or carbohydrates
  • Stimulants such as caffeine or ephedra that increase metabolism
  • Products such as conjugated linoleic acid that claim to change the body composition by decreasing fat
  • Appetite suppressants such as soluble fibers

Her findings, ScienceDaily reported, are unlikely to ever show up in promotional materials for the weight supplement/diet pill industry:

[Monroe] found that many products had no randomized clinical trials examining their effectiveness, and most of the research studies did not include exercise.

Most of the products showed less than a two-pound weight loss benefit compared to the placebo groups. …

“The data is very strong that exercise is crucial to not only losing weight and preserving muscle mass, but keeping the weight off,” [Manore said] … “For most people, unless you alter your diet and get daily exercise, no supplement is going to have a big impact.”

Professor Manore’s research, which involved an analysis of more than 100 separate studies of weight supplements, was published online by the International Journal of Sports Nutrition and Exercise Metabolism.

Of course, Professor Manore isn’t the first expert to question the effectiveness of weight loss supplements — or to encourage would-be weight-losers to adapt a healthier overall lifestyle.

For example, the weight loss section of the Mayo Clinic website features the following advice:

The reality is that there’s no magic bullet for losing weight. The most effective way to lose weight and keep it off is through lifestyle changes: Eat healthy, low-calorie foods, watch portion sizes and be physically active. It’s not magic, but it works.

This advice is echoed by the weight loss experts at  Wellspring at Structure House, a residential weight loss program for adults in Durham, North Carolina:

Achieving weight loss goals and keeping the weight off require you to change the way you think about nutrition, exercise, and the role food plays in your life. This emphasis on behavior change is what makes Wellspring at Structure House so unique.

Weight loss programs typically focus only on physical factors related to weight loss. At Structure House, you learn specific cognitive-behavior therapy strategies that help you find weight loss success, experience greater happiness, and significantly improve your overall health.