The magazine consulted with medical experts on a variety of aspects of the 32 reviewed diets: weight-loss potential (both short and long-term), ease, nutritional quality, safety, efficacy in treating diabetes, and the "heart healthy" quotient. From these individual scores, the experts assigned each diet an overall score and then ranked them.
The overall winner? DASH (Dietary Approaches to Stop Hypertension) — a low-fat, high-carb, moderate-protein diet developed by the National Heart, Lung, and Blood Institute (NHLBI). The overall loser? Paleo — the "primal" or "caveman" diet that's gained massive popularity over the past few years. Ahead, we break down a few of U.S. News & World Report's top and bottom picks, and offer our own two cents on the tried, the true, and the trendy.
The DASH diet takes into consideration your age, gender, and activity level, then recommends daily food servings and calorie counts. A moderately active woman in her 20s should consume 2,000 to 2,200 calories per day — including six to eight servings of grains (the most consumed food type on this diet) and two to three servings of fats and oils (the least consumed food type here).
The aim of this diet is to lower blood pressure, but it can help with weight loss if your diet is designed with calorie deficits built in. In some ways it's similar to the Mediterranean diet, emphasizing whole grains and extremely low levels of saturated fats. Because of its original intent to lower hypertension, the diet also advises against salt intake.
In addition, DASH is relatively easy to adhere to. You can transition your dietary habits relatively quickly by simply cutting out oils, fats, and salty, processed foods while upping lean protein, complex carbohydrates, and fresh fruits and vegetables. Simply put, it's just eating "healthier" versions of the stuff you already consume.
If you'd like to read a thorough description of the diet and its health philosophy, the NHLBI provides a six-page outline.
Oddly, the Slimfast diet (yes, the weight-loss shakes your mom used to drink in the '90s) was ranked number 13 on the list. The U.S. News & World Report researchers felt that this low-calorie diet (a draconian 1200 per day) scored well in ease of compliance, safety, and nutrition.
You substitute almost all of your normal eating routines with pre-made, processed snacks and shakes made by Slimfast. You're allowed one 500 calorie meal per day outside of the regimen. Despite its decent score, I can't imagine Slimfast being a sustainable way to lose weight or get healthier.
Life changes should be exactly that — a true shift in bad habits. Eating low-calorie candy bars and meal substitutes for eight-to-10 weeks, then hoping for this to effect real-life changes seems a bit misguided. Simply transitioning to healthful, lower-calorie whole foods would likely be more beneficial.
The Paleo diet — also called eating "primal" — has been the darling of the online community this year. This dietary philosophy is aimed at gaining strength, increasing energy, and avoiding so-called "diseases of civilization" (like diabetes and hypertension). This moderate-to-high-fat, moderate-to-high-protein diet eschews any modern dietary trappings. So, no candy, no grains, no legumes, nothing processed. In short, nothing that a pre-agricultural-revolution human would not have eaten.
Essentially, you're left with proteins, vegetables, nuts, and fruits. While not the simplest diet to adopt in a world of hamburger buns and processed protein bars, there is some evidence to suggest that it can assist in weight loss. U.S. News & World Report states that it's unknown whether the diet can prevent or control diabetes, though I think it's reasonable to assume that a diet which reduces weight and totally eliminates sugar might help prevent Type 2 diabetes.
At 23% of daily calories from carbs — we're talking fruit and vegetable, not breads and grains — Paleo falls far below the U.S. government's recommendation of 45% to 65%. Does it have cardiovascular benefits? Also unknown. Basically, we need more research on this — and other —low-carb diets. But, I wouldn't write them totally off like U.S. News & World Report did.