Once again, U.S. News & World Report has released its rankings of the best and worst diet plans. For the third year in a row, the DASH diet topped the best diets list, followed by the TLC Diet, the Mediterranean Diet, Weight Watchers and the Mayo Clinic Diet. The Paleo diet was named worst overall, followed by the Dukan diet and the raw food diet. This year’s report also includes, for the first time, an independent ranking of plant-based diets.
But what does it mean? That’s what we were wondering when we discussed the upcoming diet rankings in an editorial meeting last week. Who chooses the best and worst diets? What are the evaluation criteria? What’s even considered a “diet?” Read on. I poured through the billion different pages of the online report so you don’t have to. [If you don't care what it all means and just want to see some best and worst lists, jump to page two.]
How many diets were evaluated?
For 2013, the U.S. News & World Report panel looked at 29 diets. Some of these are what you might consider fad diets; some are popular commercial diet plans such as Weight Watchers; and some are less “diets” in the weight-less sense of the word that many people think of and more patterns of eating, (i.e., “traditional Asian diet”).
Who did the evaluating?
The diets were judged by an independent panel of 20 health and diet experts, including registered dietitians, nutrition professors, physicians, nutritionists, researchers and public health scholars. You can see the whole list here.
What criteria were diets evaluated on?
Each diet was evaluated on seven factors, including nutritional completeness, weight loss potential, safety, heart healthiness and ease of compliance. Once the experts submitted their ratings, U.S. News & World Report assigned scores from 5 (highest) to 1 (lowest) for each diet on each factor. The Best Diets report actually includes eight different rankings: Best Diets Overall (which combines panelists’ ratings in all seven categories), Best Commercial Diet Plans, Best Weight-Loss Diets, Best Diabetes Diets, Best Heart-Healthy Diets, Best Diets for Healthy Eating, Easiest Diets to Follow and Best Plant-Based Diets.
• Best Diets Overall combines ratings in all categories, though all categories were not equally weighted. Short-term and long-term weight loss were combined, with long-term ratings getting twice the weight, and safety was double-counted, “because no diet should be dangerous.”
• Best Weight-Loss Diets combines short-term and long-term weight-loss ratings, weighting both equally.
• Best Diets for Healthy Eating combines nutritional completeness and safety ratings.
• Easiest Diets to Follow averages panelists’ judgments about each diet’s taste appeal, ease of adjustment, ability to keep dieters feeling satiated and specialized requirements.
• Best Plant-Based Diets uses the same approach as Best Diets Overall to rank 11 plans that emphasize minimally-processed, vegetarian foods.
Now that we’ve covered that, here’s a brief look at some of the best and worst diets within these categories.