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What does science say about popular weight-loss plans?

Watch the right channels and you can probably name a dozen or more popular commercial weight-loss plans competing for your attention. And why not, right? More than one-third of the American population is clinically obese and many want to make a change. In 2014, weight-loss programs were a 2.5 billion dollar business. So, what does science say about commercial weight loss plans? Let’s take a look.

Overview of the science

Researchers at Johns Hopkins University set out to systematically review thousands of weight-loss studies for the purpose of answering our question. Ultimately, the team reviewed over 4,200 different studies. Their findings were published in the Annals of Internal Medicine, titled “Efficacy of Commercial Weight-Loss ProgramsAn Updated Systematic Review.”

In order to be chosen, a study had to run at least 12 weeks, and it had to be randomized and controlled (meaning participants were broken into two groups: one group using the weight-loss plan and the other acting normally for control). Studies that did not meet accepted standards of scientific reliability were filtered out. Only 39 studies met these standards. They covered 11 weight-loss programs.

  • Weight Watchers
  • Jenny Craig
  • NutriSystem
  • HMR
  • Medifast
  • Atkins
  • SlimFast
  • Biggest Loser Club
  • eDiets
  • Lose It!

The best results

Based on their analysis of the 39 studies and 11 programs, the researchers determined that Weight Watchers and Jenny Craig were the only plans backed by randomized controlled trials that showed weight loss over a year’s time. Even then, their loss was just a modest 3-5% more than the control. The NutriSystem plan also showed more weight loss over just a three month period when compared to the control group, however no long term studies were found and for co-author Dr. Jeanne Clark, that’s a significant problem. “Those benefits are long-term goals; losing weight for three months, then regaining it, has limited health benefits. That’s why it’s important to have studies that look at weight loss at 12 months and beyond.”

This leads us to the researchers’ primary conclusion. The weight-loss industry as whole is not evidence-based. If you’re concerned with choosing a weight-loss plan whose effectiveness stands up to the rigors of scientific testing, your best (and only) bets are Weight Watchers and Jenny Craig. In their published report, the researchers remarked that “additional studies evaluating long-term outcomes are needed.”

Regulation or a lack thereof

So we’re left knowing that the vast majority of weight-loss programs are not backed by reliable science. One of the biggest problems here is that, by law, a weight-loss company has no responsibility to provide scientific backing for their product or plan. Yes, that’s right, they are not required to scientifically show the efficacy of their product. One of the only avenues of reprieve is that they cannot advertise with objectively false claims. The Federal Trade Commission wants our help to rein in the misleading advertising rhetoric, but even they readily admit that it is just a little too difficult to effectively regulate. And that’s only after a product is on the market.

Granted, that’s not entirely surprising. When it comes weight-loss supplements, the Food and Drug Administration would like to remind everyone that “under the Federal Food, Drug and Cosmetics Act (as amended by the Dietary Supplement Health and Education Act of 1994), dietary supplement firms do not need FDA approval prior to marketing their products. It is the company’s responsibility to make sure its products are safe and that any claims made about such products are true.”

The health and wellness industry is the regulatory equivalent of the Wild Wild West.

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