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. 

If you like eating meat and want to lose weight, you might be tempted to try this recent extreme diet fad that proponents have made some pretty outrageous claims about. One: that eating nothing but meat can cure you of autoimmune diseases. The problem is that there’s no good research to support that notion, or any other health claim, for that matter. Indeed, omitting foods known to be good for you — fruits and veggies among them — can lead to a bunch of unwanted side effects, including constipation and potentially dangerous nutrient deficiencies. Still, since you’re cutting out so many food groups, there’s a decent chance you’ll lose weight, experts say. Regardless of any possible benefits you might see, this restrictive approach is definitely one you’ll want to ask your doc about before you even consider diving in.
"Research continues to support the role of a high-protein diet and weight loss, however, we don't want to reach those protein needs exclusively with animal proteins. Plant proteins found in beans not only help us feel full and stabilize blood sugar but beans are associated with longevity. Who cares about being skinny if you die young?" —Jennifer McDaniel, MS, RDN, CSSD, LD, food and nutrition expert
Avoiding salt doesn’t mean your food has to be bland. Experiment with using different herbs and spices. Try adding fresh cilantro and cumin to grilled fish, lemon and rosemary to chicken, or ginger and Chinese five spice to tempeh or beef. Pick up some spice blends from your local market to help add more spice to your life… just read the ingredients and make sure there’s no salt added. It’s hard to ditch salt, but these weight-loss motivation mantras will help you through the salt-less desert and into weight loss.
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 best diet for losing weight is Weight Watchers, according to the experts who rated the diets below for U.S. News. Volumetrics came in second, and the Flexitarian Diet, Jenny Craig and the vegan diet were third on this overall weight loss ranking list, which takes into account short-term and long-term weight loss scores. Some other diets performed as well or better in our rankings for enabling fast weight loss, but long-term weight loss is more important for your health.
Consequently, researchers have widely discredited the hCG diet, which involves using hCG injections, pellets, sprays, or drops, and consuming  as few as 500 calories daily. The diet is problematic not only because there’s a lack of research on hCG supplements, but also because the calorie requirement is dangerously low, potentially leading to nutrient deficiencies, fatigue, hormone imbalances, blood clots, and other issues. Thus, most experts agree the hCG diet is not safe for anyone, the Mayo Clinic notes. (35)
“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.”
Based on the concept of caloric density, which states that some foods have few calories in proportion to their size (say, a lettuce), while others have lots of calories packed in small portions (a regular chocolate chip cookie comes to mind), Volumetrics divides foods into 4 categories based on their calorie/volume ratio, and is perfect for people looking to binge on some foods while still shedding pounds. However, as with the calorie counting approach, Volumetrics does not take into account the quality of the calories, prioritizing quantity instead. The app Noom and Weight Watchers (both reviewed above) share similarities with this diet theory.
Consequently, researchers have widely discredited the hCG diet, which involves using hCG injections, pellets, sprays, or drops, and consuming  as few as 500 calories daily. The diet is problematic not only because there’s a lack of research on hCG supplements, but also because the calorie requirement is dangerously low, potentially leading to nutrient deficiencies, fatigue, hormone imbalances, blood clots, and other issues. Thus, most experts agree the hCG diet is not safe for anyone, the Mayo Clinic notes. (35)
"When clients come to me, many of them have been through the diet wringer. They've tried every fad and gimmick and, of course, they've failed to maintain long-term success. The key to losing 10 pounds and weight loss, in general, is to never feel like you're on a diet, because diets don't work. If you feel deprived, you will never make it past a few weeks. The only way to achieve long-term weight loss is to learn to appreciate food as fuel and slowly replaced processed food that cannot properly energize the body with real food that can. After a while this will become second nature and won't feel like a daily struggle." — Laura Burak, MS, RD, CDN
Created in 2003 by cardiologist Arthur Agatston, this low-carb diet features three phases. The first phase is the most restrictive, limiting carbs such as potatoes and rice. Each subsequent phase becomes more lenient, and the diet emphasizes lean protein, unsaturated fats, and low-glycemic carbs such as nonstarchy vegetables. South Beach promotes lasting lifestyle changes, according to the Mayo Clinic. (21)
If you're not up for crunching numbers every day, you can take a more generalized approach. “For some people, it’s knowing, ‘Typically I eat a whole sandwich,’” says Gagliardi. “Now, I’m going to eat half a sandwich at lunch and save the other half for my dinner and cut my calories in half." To get started, consider these 25 ways to cut 500 calories a day.
"Stop focusing on calories and start focusing on the quality of the foods you eat. High-quality diet options are natural, whole, minimally processed foods, like vegetables, fruits, nuts or seeds that offer a lot more nutritional value in the form of vitamins, minerals, healthy fats and fiber. These foods help tame hunger naturally and nourish our cells at the deepest level so that we aren't left with constant cravings. — Michelle Loy, MPH, MS, CSSD, Registered Dietitian Nutritionist and owner of Go Wellness in Orange County, California
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.
×