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.
There are many ways to do intermittent fasting — ranging from fasting for a number of hours each day up to an entire 24-hour fasting period one or two times a week. “If you're trying to kick a habit like eating late into the night, then stopping eating earlier in the evening and fasting overnight could be beneficial for you,” says Hultin. “There are many types of intermittent fasting, so ensuring you pick one that works for you and your lifestyle is important.”
The MIND diet, or Mediterranean-DASH Intervention for Neurodegenerative Delay, is a sort of hybrid between the DASH diet and the Mediterranean diet. It features foods meant to slow the progression or development of Alzheimer’s disease, the most common form of dementia and an incurable neurodegenerative condition that more than 5 million Americans are living with, according to the Alzheimer’s Association. (12) Some research backs up this notion, including a study published in September 2016 in Alzheimer’s Dementia that found a link between following the MIND Diet and a reduced risk of the disease. (13)

By allowing a daily intake of 1,200 to 1,600 calories, broken into a ratio of 50% carbs, 25% protein, and 25% fat (except for the low-carb plan), Diet-to-Go’s portions achieve a caloric middle ground that provides you with energy and the feeling of fullness while still being low enough to allow for slow-but-steady weight loss. In short, you’ll shed 1 to 3 pounds per week without feeling “hangry” all the time.
Flexitarian: A mix between the words “flexible” and “vegetarian”, the Flexitarian diet can be described as a vegetarian going on a short carnivore vacation. It is a mostly vegetarian diet that sometimes incorporates meat, fish, and poultry, and it is ideal for people who want to benefit from vegetarianism but cannot resist the temptation of animal products.  Also, a recent study suggests that, by going meatless from time to time, you may actually help in the fight against climate change. 

Once you subscribe and place your order, each week you’ll receive fully prepared breakfasts, lunches, and dinners, (and also snacks or protein shakes, depending on the plan you choose). The items will come in a box that keeps food frozen for 6 to 8 hours, and each food packet is individually labeled and complete with its nutritional information. Also, all the 4-week plans allow for free shipping.
Contrary to other low-carb approaches, the South Beach Diet makes a clear distinction between “good” and “bad” fats (avocado oil is good, butter is bad), and only prohibits the consumption of certain, but not all, carbs. This means that, while the South Beach Diet has certain similarities with the keto approach, is not strictly ketogenic, but rather keto-friendly.
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.)

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.
×