It’s shocking how rarely diet products and programs report any average statistics on exactly how well they work. If you’re looking at weight loss options, it’s worth investigating.
Most popular diet products or programs use spokespeople, and focus on a single success story – sometimes of a celebrity – to promote the diet product’s quality. This rarely informs you of how well the diet plan works on average for its users. And those kinds of report or statistical data are hard to find.
Since it’s so important how well a diet works, one might wonder why the diet’s promoters don’t do many statistical studies. One reason could be that the average results on many popular diets are surprisingly unimpressive. After one or two years, many of the diet studies report just a few pounds of weight loss is maintained.
There are statistics and reports on what diets work best, but it takes some clever searching to find them. There aren’t a lot of diet studies relative to other research, but this article covers some of the clearest reports.
One of the diet programs best known for reporting its valid statistics is Weight Watchers. Because the participants in Weight Watchers weigh-in personally, getting the valid measurement data is somewhat easier than with other programs.
A study published in the British Medical Journal in May of 2006 compared the effectiveness of four popular diet programs, Atkins, Weight Watchers, SlimFast and Rosemary Conley (a popular U.K. diet guru). After eight weeks, participants in the Weight Watchers group lost an average of 2.16 inches in waist measurement, those on Atkins lost an average 2.63 inches in their waists, SlimFast users lost an average of 1.88 inches in waist measurement, and Rosemary Conley dieters lost 1.77 inches.
Participants in a pilot study of Zonital International’s Zburn fat burning product, created an average loss of 2.5 inches in waist measurements in just two weeks. By comparison, that’s a more aggressive loss than the results in the British study. Participants in the Zburn study experienced fat loss as measured by reduced body circumference measurements in several places, waist, hips, chest, neck and thighs.
The FDA and CDC consider “healthy” weight loss to be a loss of 1 to 2 pounds per week. Zburn produced healthy weight loss for participants, as did some of the diets in the British study, including Weight Watchers, Atkins, and SlimFast.
Muscle weighs more than fat, so in measuring diet results, changes in body circumference may be more helpful in determining success of a program, especially if the participant is exercising.
The New England Journal of Medicine published a study in February of 2006, in which various macro-nutrient types of diets were compared, such as high carb/low carb. This study did not compare brand name programs, just diet type. It turned out that reduced calorie diets were the only ones that resulted in meaningful weight loss, no matter what the macro nutrient focus. In other words, long-term, it was “low-calorie” that created success.
Taking into account info from a study published in the American Journal of Clinical Nutrition, June 2007, the Daily Beast website ranked Volumetrics as #1 in effectiveness. The Volumetrics eating plan features lots of fruits and veggies, or food with high water volume content, giving these foods more “volume” and making the diet seem more filling.
A study published in the Annals of Internal Medicine January 4, 2005, was featured in a CBS new report, and it confirmed a common medical consensus that diet success statistics are uncommon. Diet program results are also sometimes surprisingly unimpressive as compared to the better-than-average results of featured spokespeople. The study did confirm that Weight Watchers participants lost about 10 pounds, or 5% of their initial weight in six months, and that they kept about half of it off two years later. But there was not enough verifiable data from other diet plans to make firm conclusions.
A study was also published by the American Dietetic Association in October ’07, which focused on nutritional value of popular diets. The most nutritious in their report were Ornish, followed by Weight Watchers high carbohydrate, and then by the New Glucose Revolution diet. These were the top three. But it was not a ranking of weight loss results – only nutritional value.
Few of the most popular commercial diet plans themselves – with the exception of Weight Watchers and Zburn – seem to offer any statistical evidence of how well they work on average or typically, from their own studies. The FTC is now requiring diet plans that use a spokesperson quoting their weight loss, to also disclose what “typical” results are, because those spokesperson results are very non-typical. Look for these required disclosures in the tiny, tiny fine print as you evaluate the best diet choice for you.
To do an internet search of diet results yourself, use a search engine and type in things like “published research studies – diets” or the diet product’s name, and combine it with “research” or “success statistics”. New studies are constantly happening, and it’s worth an updated search when you begin any diet plan.