Health knowledge and news provided by doctors.

Comparison Between Atkins, South Beach, Weight Watchers and Zone Dieting

Tim Boyer's picture
Atkins Diet vs South Beach Diet

Are you on a particular diet plan at this moment? Did you know that many commercial diet plans may not be all that effective toward weight loss and decreasing the risk factors of heart disease? Here is what a new study revealed in a comparison between Atkins, South Beach, Weight Watchers and Zone Dieting.


According to a news release by McGill University, the health implications of going on any of the more popular commercial diet plans is more murky than clear when it comes to keeping the weight lost off after the first year and the actual impact it has toward cardiac health.

“Despite their popularity and important contributions to the multi-million dollar weight loss industry, we still do not know if these diets are effective to help people lose weight and decrease their risk factors for heart disease,” said the study’s lead author Dr. Mark J. Eisenberg, a professor in the Faculty of Medicine, a cardiologist at the JGH and an epidemiologist at the LDI.

“With such a small number of trials looking at each diet and their somewhat conflicting results, there is only modest evidence that using these diets is beneficial in the long-term.”

To address this concern of whether diet plans are doing any good in the long run, Dr. Eisenberg and colleagues conducted a systematic review of the efficacy of the Atkins, South Beach, Weight Watchers, and Zone dieting with a particular focus on sustained weight loss after the first year of dieting.

Digging through a range of medical databases for randomized controlled trial studies involving the aforementioned weight loss plans, the researchers came up with some surprising conclusions. In spite of previously reports of how effective these popular weight loss programs are, the researchers revealed these findings:

• In trials comparing Weight Watchers to usual care, Weight Watchers dieters lost an average 7.7 to 13.2 pounds after one year compared to 1.8 to 11.9 pounds with usual care; however, at two years, the weight lost was partially regained. (Usual care refers to traditional methods to promote weight loss such as low-fat diets, behavioral weight loss intervention, nutritional counseling, or self-help materials.)

• Results from trials on the Atkins diet were inconsistent. In the only trial comparing the South Beach diet to usual care, no difference in weight loss occurred in 12 months; however, the participants in this study were both severely obese and had undergone gastric bypass surgery.

Follow eMaxHealth on YouTube, Twitter and Facebook.
Please, click to subscribe to our Youtube Channel to be notified about upcoming health and food tips.

• Trials involving head-to-head comparisons between Atkins, Weight Watchers, Zone and usual care suggest that all four result in a modest weight loss at one year, as did those in the control group who received the usual care. Those on the Atkins diet lost an average 4.6 to 10.3 pounds; Weight Watchers participants lost an average 6.6 pounds; Zone dieters lost an average 3.5 to 7 pounds; and control lost about 4.85 pounds.

• In studies involving head-to-head comparisons, there were no marked differences between Atkins, Weight Watchers and Zone diets at improving cholesterol, blood pressure, blood sugar levels, or other cardiovascular risk factors.

The researchers concluded that despite the millions of dollars spent on popular commercial diets, the actual data found thus far is conflicting and insufficient to identify one popular diet as being more beneficial than the others. They found that Atkins, Weight Watchers and Zone dieting achieved modest and similar long-term weight loss, but that large clinical comparison trials which directly focus on the differences in efficacy and cardiac health benefits between the diet plans are needed.

According to McGill University, Dr. Eisenberg added that:

“A broader lifestyle intervention, which also involves doctors and other health professionals, may be more effective,” he says. “This also tells doctors that popular diets on their own may not be the solution to help their patients lose weight.”

Image Source: Courtesy of Wikimedia Commons

Long-Term Effects of 4 Popular Diets on Weight Loss and Cardiovascular Risk Factors” Circulation: Cardiovascular Quality and Outcomes Published online before print November 11, 2014, Renée Atallah, MSc, et al.

McGill University news release: “Long-term benefits of popular diets are less than evident



Beneficial for weight loss is one thing, but what about beyond that - looking at the long-term health benefits from lower inflammation, like with the Zone diet. With Atkins, there is probably a higher risk of colon cancer from meat protein. I don't think this study should have been funded. And Weight Watchers always gets good reviews. :)