What the Heck Is the Zone Diet (and Does It Actually Work)?

Your sister has tried every diet trend, from keto to Paleo to plant-based. This month, she’s really into the Zone Diet, a low-carb diet designed to reduce inflammation. But is it effective (and more importantly, is it safe)? We investigate.

Wait, what’s the Zone Diet? It’s a low-carb, rigidly balanced meal plan designed to reduce inflammation and aid in weight loss. The Zone Diet was created by biochemist Barry Sears, who published dozens of books about the diet. Proponents believe that by balancing each meal and snack to a ratio of 30 percent protein, 30 percent fat and 40 percent carbs you will rev up your metabolism and lose more fat, as opposed to muscle or water weight.

And what can I eat? Zone dieters eat three meals and two snacks per day, with a source of lean protein, like chicken breast or salmon; a source of carbs (usually fresh veggies); and a small amount of healthy fat, like olive oil, avocado or walnuts. On a given day, women typically eat 1,200 calories and men eat 1,500 calories.

So what can’t I eat? Great news: There are no off-limits foods on the Zone Diet, but the plan recommends heavily restricting pasta, grains and bread, as well as fruits and veggies that are high in sugar, like bananas, carrots, corn and raisins.

And does it actually work? After polling our nutritionist friend Melissa Kelly, MS, RD, CDN, the verdict is...kinda. "The Zone Diet's calorie cap [see above] follows the recommendations of the Joslin Diabetes Center in Boston for managing obesity and diabetes," Kelly told us. "The research casts doubt on its 40-30-30 ratio, with weight loss a product of restricting calories, versus the ratio. So following this type of ratio doesn't promote fat-burning or weight loss more than any other nutritionally sound diet does." In short, any diet that restricts calories will help you lose weight, but there’s no proof that the Zone Diet helps increase your metabolism or burn a larger amount of fat than any other low-calorie eating plan.

Will trying the Zone Diet do any harm, though? No, as long as it’s OK with your doctor and you have no underlying medical conditions. If you’re consuming fewer calories on the Zone Diet than you typically would, you’re likely to lose weight. But if you’re like us, and adore pasta and bread, it might be tricky to stick to this diet in the long run.