Given that all participants in the study were overweight and “healthy”, what was not studied, and could have been very useful, was what was the impact of the two diets on participants’ blood sugars (HbA1c), insulin levels, and on some measure of inflammation. It is possible that there could have been little difference in weight loss between the two diets but big differences in the impact on risk factors related to diabetes.
Vegetarians are generally thinner and healthier than meat-eaters, according to a 2013 study published in the American Journal of Nutrition and Dietetics. While going totally vegetarian may not be realistic for you, one way to slim down your meals is to replace some meat with plant protein. Black beans, for example, give you 15 grams of protein per serving, and mushrooms are rich in umami flavor, and can be used to replace half the ground beef in most recipes.
If you’ve been eating fast food for years, get real about your approach: You’re probably not going to stick to an organic, gluten-free, paleo overhaul for very long. "You want to change as little as possible to create calorie deficit," says Dr. Seltzer, who insists the best way to support sustainable weight loss is to incorporate small changes into existing habits. So instead of giving up your daily BLT bagels in favor of an egg-white wrap, try ordering your sandwich on a lighter English muffin. Or say you eat a snack bar every afternoon: Swap your 300-calorie bar for a 150-calorie alternative. "Your brain will feel the same way about it, so you won’t feel deprived," he says.
Sure, there's your one friend who swears by the Taco Cleanse. And that other friend who ate nothing but broccoli soup for a month and dropped 20 pounds, found the love of her life, and got promoted at work. But before you start blending 80 stalks of broccoli into a cup or crunching your way through a crate of tacos, check out which diets are backed by science. Because don't you want to try one that will do the trick for you?