Fad diets can be so seductive:
They typically offer simplified shopping lists, rules that are easy to remember, and promises of big results. But do the results actually come through? It seems that no one, besides the companies offering those books and products, has really taken a comprehensive look into their effectiveness, until now.
A group of scientists decided to take a deep dive into four fad diets, Atkins, South Beach, Weight Watchers, and Zone, to examine their effectiveness in terms of weight loss and reduced risk of cardiovascular disease, particularly in the long term (or over 12 months). Their results, published this week in the journal Circulation: Cardiovascular Quality and Outcomes, show that not only are the diets largely ineffective, but their big claims weren't properly supported in the first place.
The researchers began by systematically searching for clinical trials of the four diets, which they chose for their popularity. Their primary goal was to find sustained weight loss after 12 months, with more minor goals being changes in body fat, body mass index, waist circumference, blood pressure, and other measures of health.
They found immediate issues with the trials they focused on, finding that the studies hadn't followed proper scientific protocol. For example, they noted that the studies typically used young, white, female, obese participants, giving the potential for bias. (What about men, or any other ethnic group?) They also found that there were very few studies that tested long-term benefits of the diets, or any results after 12 months.
Even putting all those major scientific problems aside, the diets just weren't that effective. Their mean weight loss, across all trials, hovered around six to 10 pounds,and that was just at first. By the 12-month mark, the weight was mostly regained and mirrored the participants in the control group (that is, the people who didn't diet). There was also limited change in cholesterol levels and blood pressure.
Those fad diets require a big commitment and big purchases (packaged food, books, and other products) for relatively little pay-off. The researchers noted that the weight-loss market in the U.S. made around $66 billion in 2013, which is pretty crazy if few people are seeing results.
Of course, the choice of diet is up to you. If you love your South Beach diet and feel it is helping your body, then go with it. But when the next fad diet comes along, feel free to feel suspicious, and take a look to see if there’s any unbiased science actually backing up those lofty claims. While it's not as sexy, the real solution for lasting weight-loss may just be making smarter eating and exercise choices.