November 12, 2003
The good news about four major diets is that they all work. The bad news is they don't work as well as consumers want them to -- but they do produce significant health benefits even when weight loss isn't dramatic.
In the first long-term, head-to-head test of four well-known diets, Tufts University researchers found that the Atkins, Ornish, Weight Watchers and Zone diets were all somewhat effective. They all produced some weight loss and did not prove dangerous.
Best of all, the four diets all reduced participants' risk of heart disease to a statistically significant degree.
The study was conducted over 12 months using 160 overweight volunteers who were randomly assigned to one of the four diets. Their food consumption was measured throughout and blood and urine samples were taken frequently to ensure that the diets were not causing unexpected health risks.
The findings:
- No miracles. Most participants lost four to six pounds.
- Persistence pays. Those who stuck with the diets for the full year got the best results.
- Moderation is more bearable. About half those on the more restrictive Atkins and Ornish diets dropped out early. Two-thirds of those on the more moderate Weight Watchers and Zone diets stuck it out for the full year.
- All reduced heart disease risk. While the weight loss results may not have been dramatic, all four diets reduced the risk of heart disease. The biggest reduction was in the Weight Watches group (15%) followed by Atkins (12%), the Zone (11%) and Ornish (7%).
The results were presented to the American Heart Association's annual meeting in Orlando.
So what's the best diet? It's the one you can live with, year after year. "The idea of one best diet for everyone is probably an old-fashioned notion," said Michael Dansinger, the study's lead researcher.
