February 2015 Issue

“On and Off” Diets May not Work

What’s the best way to lose weight? That’s the question that spurs the $20 billion per year U.S. weight loss industry. Increasingly, research suggests that an array of popular weight loss diets can help you lose weight, but over the long term they may not be so effective.

In a new study published in Circulation: Cardiovascular Quality and Outcomes (November 2014), Canadian researchers compared the results of randomized clinical trials on four popular diets: South Beach, Weight Watchers, Zone, and Atkins. They found that all four diets were moderately effective at decreasing weight in the short term, but weight loss was not sustained over the long term. In fact, when compared to usual care, Weight Watchers was the only plan that was consistently more effective at reducing weight at the 12-month mark, with an average weight loss of 7.7-13.2 pounds after one year. However, at 2 years the weight lost was partially regained.

It’s becoming clear that short-term diet solutions—that people go “on” and “off”—are not the answer to weight loss. Instead, adapting a long-term, sustainable strategy that involves a lifelong shift in eating behaviors, food choices, and physical activity may be the most successful approach. Perhaps it’s time to replace our current notion of “dieting” with the more positive message: Healthy eating for life.

—Sharon Palmer, RDN, Editor EN