It’s estimated that nearly half of American adults attempt to lose weight each year ( 1 ).
One of the best ways to lose weight is by changing your diet.
Yet, the sheer number of available diet plans may make it difficult to get started, as you’re unsure which one is most suitable, sustainable, and effective.
Some diets aim to curb your appetite to reduce your food intake, while others suggest restricting your intake of calories and either carbs or fat.
What's more, many offer health benefits that go beyond weight loss.
Here are the 8 best diet plans to help you shed weight and improve your overall health.
Intermittent fasting is a dietary strategy that cycles between periods of fasting and eating.
Various forms exist, including the 16/8 method, which involves limiting your calorie intake to 8 hours per day, and the 5:2 method, which restricts your daily calorie intake to 500–600 calories twice per week.
How it works:
Weight loss:
The same review showed that this way of eating may reduce waist circumference by 4–7%, which is a marker for harmful belly fat ( 2 ).
Other studies found that intermittent fasting can increase fat burning while preserving muscle mass, which can improve metabolism ( 3 , 4 ).
Other benefits:
Downsides:
That said, those sensitive to drops in their blood sugar levels, such as some people with diabetes, low weight, or an eating disorder, as well as pregnant or breastfeeding women, should talk to a health professional before starting intermittent fasting.
Summary
Plant-based diets may help you lose weight. Vegetarianism and veganism are the most popular versions, which restrict animal products for health, ethical, and environmental reasons.
However, more flexible plant-based diets also exist, such as the flexitarian diet, which is a plant-based diet that allows eating animal products in moderation.
How it works:
The vegan diet takes it a step further by restricting all animal products, as well as animal-derived products like dairy, gelatin, honey, whey, casein, and albumin.
There are no clear-cut rules for the flexitarian diet, as it’s a lifestyle change rather than a diet. It encourages eating mostly fruits, vegetables, legumes, and whole grains but allows for protein and animal products in moderation, making it a popular alternative.
Many of the restricted food groups are high in calories, so limiting them may aid weight loss.
Weight loss:
A review of 12 studies including 1,151 participants found that people on a plant-based diet lost an average of 4.4 pounds (2 kg) more than those who included animal products ( 10 ).
Plus, those following a vegan diet lost an average of 5.5 pounds (2.5 kg) more than people not eating a plant-based diet ( 10 ).
Plant-based diets likely aid weight loss because they tend to be rich in fiber, which can help you stay fuller for longer, and low in high-calorie fat ( 11 , 12 , 13 ).
Other benefits:
Downsides:
A flexitarian approach or proper supplementation can help account for these nutrients.
Summary
Low-carb diets are among the most popular diets for weight loss. Examples include the Atkins diet, ketogenic (keto) diet, and low-carb, high-fat (LCHF) diet.
Some varieties reduce carbs more drastically than others. For instance, very-low-carb diets like the keto diet restrict this macronutrient to under 10% of total calories, compared with 30% or less for other types ( 18 ).
How it works:
They’re typically higher in protein than low-fat diets, which is important, as protein can help curb your appetite, raise your metabolism, and conserve muscle mass ( 19 , 20 ).
In very-low-carb diets like keto, your body begins using fatty acids rather than carbs for energy by converting them into ketones. This process is called ketosis ( 21 ).
Weight loss:
For example, a review of 53 studies including 68,128 participants found that low-carb diets resulted in significantly more weight loss than low-fat diets ( 22 ).
What’s more, low-carb diets appear to be quite effective at burning harmful belly fat ( 26 , 27 , 28 ).
Other benefits:
Downsides:
In very rare situations, following a very-low-carb diet may cause a condition known as ketoacidosis, a dangerous metabolic condition that can be fatal if left untreated ( 32 , 33 ).
Summary
The paleo diet advocates eating the same foods that your hunter-gatherer ancestors allegedly ate.
It’s based on the theory that modern diseases are linked to the Western diet, as proponents believe that the human body hasn’t evolved to process legumes, grains, and dairy.
How it works:
Weight loss:
For example, in one 3-week study, 14 healthy adults following a paleo diet lost an average of 5.1 pounds (2.3 kg) and reduced their waist circumference — a marker for belly fat — by an average of 0.6 inches (1.5 cm) ( 37 ).
Research also suggests that the paleo diet may be more filling than popular diets like the Mediterranean diet and low-fat diets. This may be due to its high protein content ( 38 , 39 ).
Other benefits:
Downsides:
Summary
Like low-carb diets, low-fat diets have been popular for decades.
In general, a low-fat diet involves restricting your fat intake to 30% of your daily calories.
Some very- and ultra-low-fat diets aim to limit fat consumption to under 10% of calories ( 24 ).
How it works:
Ultra-low-fat diets contain fewer than 10% of calories from fat, with approximately 80% of calories coming from carbs and 10% from protein.
Ultra-low-fat diets are mainly plant-based and limit meat and animal products.
Weight loss:
An analysis of 33 studies including over 73,500 participants found that following a low-fat diet led to small but relevant changes in weight and waist circumference ( 42 ).
However, while low-fat diets appear to be as effective as low-carb diets for weight loss in controlled situations, low-carb diets seem to be more effective day to day ( 22 , 46 , 47 ).
Ultra-low-fat diets have been shown to be successful, especially among people with obesity. For example, an 8-week study in 56 participants found that eating a diet comprising 7–14% fat led to an average weight loss of 14.8 pounds (6.7 kg) ( 48 ).
Other benefits:
Downsides:
Summary
The Mediterranean diet is based on foods that people in countries like Italy and Greece used to eat.
Though it was designed to lower heart disease risk, numerous studies indicate that it can also aid weight loss ( 53 ).
How it works:
Foods such as poultry, eggs, and dairy products are to be eaten in moderation. Meanwhile, red meats are limited.
Additionally, the Mediterranean diet restricts refined grains, trans fats, refined oils, processed meats, added sugar, and other highly processed foods.
Weight loss:
For example, an analysis of 19 studies found that people who combined the Mediterranean diet with exercise or calorie restriction lost an average of 8.8 pounds (4 kg) more than those on a control diet ( 53 ).
Other benefits:
Downsides:
Summary
WW, formerly Weight Watchers, is one of the most popular weight loss programs worldwide.
While it doesn’t restrict any food groups, people on a WW plan must eat within their set daily points to reach their ideal weight ( 57 ).
How it works:
To reach your desired weight, you must stay within your daily point allowance.
Weight loss:
For example, a review of 45 studies found that people who followed a WW diet lost 2.6% more weight than people who received standard counseling ( 62 ).
What’s more, people who follow WW programs have been shown to be more successful at maintaining weight loss after several years, compared with those who follow other diets ( 63 , 64 ).
Other benefits:
Downsides:
Summary
Dietary Approaches to Stop Hypertension, or DASH diet, is an eating plan that is designed to help treat or prevent high blood pressure, which is clinically known as hypertension.
It emphasizes eating plenty of fruits, vegetables, whole grains, and lean meats and is low in salt, red meat, added sugars, and fat.
While the DASH diet is not a weight loss diet, many people report losing weight on it.
How it works:
For example, an average person on the DASH diet would eat about 5 servings of vegetables, 5 servings of fruit, 7 servings of healthy carbs like whole grains, 2 servings of low-fat dairy products, and 2 servings or fewer of lean meats per day.
In addition, you’re allowed to eat nuts and seeds 2–3 times per week ( 65 ).
Weight loss:
For example, an analysis of 13 studies found that people on the DASH diet lost significantly more weight over 8–24 weeks than people on a control diet ( 70 ).
Other benefits:
Downsides:
Summary
Some of the most well-researched diets and eating plans include intermittent fasting, plant-based diets, low-carb diets, low-fat diets, the paleo diet, the Mediterranean diet, WW (Weight Watchers), and the DASH diet.
While all of the above diets have been shown to be effective for weight loss, the diet you choose should depend on your lifestyle and food preferences. This ensures that you are more likely to stick to it in the long term.