This approach is very user-friendly, mainly because it does not prohibit any foods and, as long as you keep your daily caloric intake below your individual threshold, you’ll lose weight. Noom claims 84% of its customers completed the plan, most of them losing 1 to 2 pounds per week. After reading hundreds of customer reviews, we believe this claim to be pretty accurate.

Once you download the app on your phone, free of charge, you’ll be asked to submit your age, weight, and weight goals, as well as information regarding your motivations, triggers, lifestyle, eating habits, and health issues. The app then uses its database to create your personalized, comprehensive diet plan and get you in touch with your goal specialist, your personal coach, and your support group.

Right now, this is the trendiest of all diet theories. It prioritizes the consumption of foods high in protein and fat while limiting the number of carbs per day to less than 20%. This means abstaining from grains, starchy vegetables, and fruits, and filling up on protein and fat. The most famous of all low-carb plans is the Keto Diet, an approach based on the metabolic process of ketosis, which happens when you restrict your carb intake to less than 0.7 grams per day and your body starts using fat, and not carbs, as its main fuel. 
A 2015 study from the Annals of Internal Medicine showed that for those who have a hard time following a strict diet, simplifying the weight loss approach by just increasing fiber intake can still lead to weight loss. Women should aim for at least 25 grams of fiber per day (based on a 2,000-calorie) diet, according to the most recent U.S. Dietary Guidelines. Start with our high-fiber diet plan.
If you want to lose weight fast, your best bet is the HMR Program, according to the health experts who rated the diets below for U.S. News. While these diets enable quick weight loss for those with a short-term goal – there's a strong chance you'll drop significant weight within the first 12 months – keep in mind that this is markedly different from long-term weight loss, which is more important for your health.
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.
Make sure that the diet has been studied extensively for safety — and discuss any changes with your physician or registered dietitian before beginning a new diet. (If you don’t have a dietitian, find one in your area at the Academy of Nutrition and Dietetics website.) And do a self-check to ensure the diet fits with your own values and preferences.
If you've been trying to eat healthy for a long time, you know how quickly you get sick of chicken breasts and broccoli. Break out of your diet rut with the Middle Eastern diet. It's based on the same principles as the Mediterranean diet but with more of an emphasis on plant-based foods and a different flavor profile. With all the tasty and healthy spices, you'll never get bored of making dinner and you'll get all the same heart-healthy benefits as its geographical cousin's diet.
"These diets are so restrictive that of course you're going to lose weight fast because you're not eating enough calories to sustain basic activities of your body, let alone any exercise. That's nothing that any person can sustain for the long term," Hogan said. "The weight's going to come back if you do lose any weight, and then it's going to be harder to lose weight in the future."
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).
To lose 10 pounds fast, Jackson explains you'll then want to cut your calorie consumption by 10%. "For example, if you average 2,000 per week, reduce that amount to 1,800 calories and see if you lose weight. You'll also want to take notice of the percentage breakdown of protein, carbs and fat. Aim for a 'bodybuilder breakdown' which is 40% protein, 40% carbs and 20% fat. You'll begin to drop weight in no time!"
"It's no big surprise, but my go-to weight loss tip is to eat more vegetables. They are the most low-calorie food you can consume, and they're filled with health-boosting, satiating nutrients. From smoothies and eggs to soups, main and side dishes, they can fit in anywhere and boost volume and nutrition. If you want to eat more while still losing weight, veggies are your answer. —Laura Burak, RD, CDN
We just don't feel full by liquid calories in quite the same way as we do real food. Drinking a juice or caramel coffee drink just isn't as satisfying as eating a bowl of veggie- and protein-packed stir-fry. So monitor your intake of juice, soda, sweetened coffee and tea, and alcoholic beverages. If you consume each of those beverages during the day, you'll have taken in at least 800 extra calories by nighttime — and you'll still be hungry. (Incidentally, alcohol may suppress the metabolism of fat, making it tougher for you to burn those calories.)
Popularized by the documentary Forks Over Knives, the Ornish diet is a low-fat, plant-based diet plan based on whole grains, vegetables, fruits, and legumes. It's based on a lacto-ovo style of vegetarianism, allowing only egg whites and nonfat dairy products. It's packed with vitamins, fiber, and lots of filling plants to keep you satiated. Some studies have shown it can reverse heart disease and have beneficial effects on other chronic health conditions. (BTW, there is a difference between a vegan diet and a plant-based diet.)
Eat like the Italians and the Greeks! This is the dietician’s darling, named #1 non-commercial diet by many experts in the health and weight management industries. It's not a fixed diet with a fixed menu, but rather a general guideline based on fruits, vegetables, beans, nuts, healthy grains, fish, olive oil, red wine (yes, red wine), and small amounts of meat and dairy. It is one of the most flexible diet plans out there, as it is highly customizable to fit anyone’s tastes and needs. It does not require calorie counting, mainly because most of the foods in this diet are filled with fiber and healthy fats, which makes you digest them slower, so you feel fuller longer.
Español: perder grasa corporal rápidamente, Português: Perder Gordura Corporal Rapidamente, Italiano: Perdere Massa Grassa Velocemente, Deutsch: Schnell Körperfett verlieren, Русский: быстро убрать жир на теле, Français: perdre rapidement de la graisse, 中文: 迅速减肥, Nederlands: Snel lichaamsvet kwijtraken, Čeština: Jak se rychle zbavit tělesného tuku, العربية: فقد الدهون بسرعة
Español: perder grasa corporal rápidamente, Português: Perder Gordura Corporal Rapidamente, Italiano: Perdere Massa Grassa Velocemente, Deutsch: Schnell Körperfett verlieren, Русский: быстро убрать жир на теле, Français: perdre rapidement de la graisse, 中文: 迅速减肥, Nederlands: Snel lichaamsvet kwijtraken, Čeština: Jak se rychle zbavit tělesného tuku, العربية: فقد الدهون بسرعة
"Eating directly out of a box or bag (almost always leads to overeating. Serve your food on a plate or in a bowl to keep portion sizes in check and to get used to what one serving looks like. Also, when we take the time to sit down during meals versus standing or driving, we tend to feel more satisfied with our meal. In fact, research shows that you will eat up to 30% more food at the next meal if you ate standing up! Serve yourself, sit down, and enjoy!" — Jennifer McDaniel, MS, RDN, CSSD, LD, food and nutrition expert
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.
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