U.S. News evaluated and ranked the 41 diets below with input from a panel of health experts. To be top-rated, a diet had to be relatively easy to follow, nutritious, safe, effective for weight loss and protective against diabetes and heart disease. The Mediterranean diet took the top spot, while the government-endorsed DASH diet, which stands for Dietary Approaches to Stop Hypertension, came in second.
“Intermittent fasting can be really challenging if you have an ever-changing schedule,” adds Hultin. “If you're traveling and crossing time zones, it could be very difficult to follow. It might be best for people with more stability in their lives.” Intermittent fasting isn’t safe for people with type 2 diabetes, children, pregnant or lactating women, or anyone with a history of an eating disorder.
Not much of a coffee drinker? Tea is also a natural diuretic, and types of herbal tea such as dandelion or fennel root can also lend a hand. In fact: When a recent study compared the metabolic effect of green tea (in extract) with that of a placebo, researchers found that the green-tea drinkers burned about 70 additional calories in a 24-hour period.
While there are many vegetarian factions, all of them share the same basic dicta: no fish, meat, or poultry. But that’s where the similarities end for this eating plan/lifestyle practiced by 18% of the world population. Studies suggest that a vegetarian diet is good for reducing cancer risks, stabilizing blood sugar, and promoting heart health, while others raise a flag regarding nutritional deficiencies including Omega 3, vitamin B, calcium, and iron. Plans range from the most flexible to the most restrictive. Here are two of the most popular examples of each extreme:
Take cauliflower gnocchi to the next level with these hearty, plant-based meal-prep bowls. Here we double up our Roasted Butternut Squash & Root Vegetables recipe (see Associated Recipes) and combine it with white beans, pesto and store-bought cauliflower gnocchi to make a week of healthy meal-prep lunches. You'll have leftover roasted veggies, so plan to use them as easy side dishes for dinner throughout the week or incorporate them into another recipe, like Creamy Roasted Vegetable Soup with Chicken or the Piled-High Greek Vegetable Pitas (see Associated Recipes).
"It's far more difficult to eat a healthier diet and fit in exercise if you don't plan ahead. Plan out your meals for the week ahead and go grocery shopping over the weekend to ensure you have the ingredients you need on hand. If you can, do some meal prep in your downtime—cut fresh veggies, marinate your protein, cook up a batch of whole grains in advance. When you're prepared you're far less likely to order takeout. — Jessica Fishman Levinson, MS, RDN, CDN, culinary-nutrition consultant and founder of Nutritioulicious
The researchers hypothesize that participants who abstained from animal products dropped significantly more pounds since plant-based foods include loads of filling fiber and slow-to-digest complex carbs. Though more research is needed to confirm these results, the study authors write, "Vegetarian diets appeared to have significant benefits on weight reduction compared to non-vegetarian diets."
Aim to get at least seven hours of sleep each night. Try going to bed and waking up at the same time each day. Why? Ever notice how you start to crave donuts and drive-thru breakfasts when you’re exhausted? When you don’t get enough sleep, your hormones are thrown out of balance. Running on no sleep can actually drive up the hormones that make you want to eat, while pushing down the hormones that signal for fullness—and that’s a recipe for weight gain. When you’re well-rested, it’s much easier to make healthy decisions and stay on track.
Ansari says alcohol can prevent weight-loss in several ways, including the fact that heavy alcohol intake can stimulate food intake. "Binge drinking can overload the liver. The liver then prioritizes processing alcohol over other nutrients and then stores the protein, carbs, and fat as fat in the body," Ansari explains. The Centers for Disease Control and Prevention (CDC) defines binge drinking as having five or more drinks for men, and four or more drinks for women in two hours. "Also, alcoholic beverages are often mixed with sugar-rich beverages. Drinking more than moderate amounts of alcohol can cause calories to add up quickly."
The easier it is to seamlessly fit a diet plan into your life without major lifestyle changes, the better. After all, by focusing on holistic long-term results rather than trendy short-term solutions, sustainability becomes the number one enemy of the feared “yo-yo” effect. During our investigative process, we asked ourselves: What makes a diet plan sustainable? After long hours of research, we decided that the following factors can determine a plan’s sustainability, and thus its odds of success:
Many diet plans cut out entire food groups, which can create nutrient deficiencies as well as health problems. For instance, if the diet is very low in carbohydrates and you have type 1 diabetes or type 2 diabetes, it’s probably not a good fit. And if it’s too restrictive and you’re pregnant or breastfeeding, it’s not a good idea, either. Keep in mind that pregnancy is not a time for weight loss. Speak with your doctor before making any changes to your diet if you are pregnant or breast-feeding.
"If I had to pick one food for weight loss, I would choose oatmeal. It's a whole grain, high-fiber carbohydrate that sticks to your ribs, so it keeps you full and satisfied. Eating it also leads to a slow rise in blood sugar, which has been shown to keep insulin levels from spiking, leading to less fat storage. The key with oatmeal is how to make it so it's not a calorie bomb. I recommend making it with nonfat milk in place of water, stirring in chopped raw nuts or natural nut butter, and topping with fresh or frozen fruits. If you need some added sweetness, a drizzle of maple syrup should do it. — Jessica Fishman Levinson, MS, RDN, CDN, culinary-nutrition consultant and founder of Nutritioulicious
There’s a reason everyone harps on about protein: Not only does it help keep you full, but it’s also responsible for repairing the tiny tears caused by strength training in your muscles. This helps them grow bigger and stronger, nudging out body fat in the process. As a general rule of thumb, aim to get at least 70 grams of protein throughout the day, says Dr. Cheskin.
“A lot of people think the foundation of a paleo diet is high-fat meat, but I suggest that it’s vegetables,” says Hultin. The concept is to eat only foods — including meat, fish, poultry, eggs, fruits, and vegetables — that would have been available to our Paleolithic ancestors. This means grains, dairy, legumes, added sugar, and salt are all no-no’s.
“This is a great way of eating that I highly recommend to many clients, and I even model in my own life,” says Elizabeth Shaw, RDN, who is in private practice in San Diego and is the co-author of Fertility Foods Cookbook. “Since the premise of the diet is designed to help people who have high blood pressure, low-sodium foods are recommended. But considering that most Americans exceed their daily sodium levels anyway, it’s not surprising that dietitians recommend this style of eating for treating many different conditions, such as heart disease and obesity.”
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.
Aim to do ab work 3 or 4 times a week on non-consecutive days with at least 24 hours of rest in between sessions, says Gagliardi. During those sessions, you can start with simpler moves like crunches, bicycle crunches, and planks. Even though you may only be directly targeting your abs 3 or 4 times a week, you should still be activating your core (aka, tightening your ab muscles) in every workout you do, says Gagliardi.
Another healthy change that will help you look better is to cut back on salt. Sodium causes your body to hold onto excess water, so eating a high-salt diet means you’re likely storing more water weight than necessary. If you’re in a rush to lose weight fast, cut out added salt as much as possible. That means keep ditching the salt shaker and avoiding processed and packaged foods, where added salt is pretty much inevitable.
The number of calories you need to maintain or lose weight depends on a number of factors, including your age, sex, height, and level of physical activity, according to the FDA. To maintain a healthy body weight, the FDA recommends that you balance the number of calories you consume with the number of calories you burn through physical activity and your body’s metabolic processes. As a rule of thumb, the FDA recommends a standard 2,000 calorie diet for the average adult.
The most basic approach to weight loss is burning more calories than you consume. For instance, since 3,500 calories equals 1 pound of fat, a weight loss app—or even just a pen and paper—can help you decide how many calories you need to cut from your diet or burn at the gym in order to meet your goals. “If you were to burn 500 more calories per day 7 days a week, that would lead to 3,500 calories in a week and 1 pound of weight loss,” says Gagliardi.