9 Best Diets To Help You Lose Weight And Keep It Off, According To Nutritionists
When you’re trying to lose weight, it can be overwhelming to decide where to start, especially when it comes to sustainable and healthy nutrition. Choosing a diet plan for weight loss that is right for you depends on lifestyle, goals, and what makes you feel good.
“A good diet for long-term weight loss is one that puts structure around food and eating but allows flexibility for preferences and likes and dislikes, is nutritionally healthy, and includes mindful eating techniques and behavior modification strategies,” says Sonya Angelone, RD, a spokeswoman for the U.S. Academy of Nutrition and Dietetics.
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Keep in mind that just because a diet can help you lose weight doesn’t mean it can help you keep it off or build healthy habits that prevents you from gaining it back. “The diet should be sustainable for long term and not be a quick fix,” adds Keri Gans, RD, the author of The Small Change Diet.
And while the best diets have a common theme—creating a calorie deficit, or having some kind of structure around food intake—you want to make sure you're eating well, not just less. “It’s really important to still make sure that you’re getting adequate nutrition,” says Jessica Cording, RD, the author of The Little Book of Game-Changers. Consider your daily intake of vitamins, minerals, proteins, and fats, she adds.
A diet can have other health benefits. “Besides weight loss, people want to feel good, have more energy, and feel confident,” says Lori Barrett, RDN, of Top Nutrition Coaching. “Maybe someone wants to avoid family genetics they have seen a parent go through like diabetes, high blood pressure, or heart concerns, or they want to lower their medication amounts through food and weight loss.” Remember that healthy eating habits have a huge impact on your life and weight loss is just one piece of the puzzle.
So, when deciding which diet is right for you (that can do all the above), think about your taste, lifestyle choices, cooking habits, social schedule, and how likely you are to stick to a plan. A diet is personal, and it’s important to find one that works best for you.
If you’re ready to embark on a weight loss journey, read on to see which diets are nutritionally sound while still helping you get results, according to nutritionists.
1. Flexitarian Diet
A big appeal of the flexitarian diet is that it’s…flexible and doesn't involve counting calories. It encourages a mostly plant-based diet while allowing you to have meat when the mood strikes. “The flexitarian diet includes all food groups, while at the same time encouraging more plant-based meals which in many instances are lower in calories,” Gans says. “You should not feel deprived on this plan.”
How it helps you lose weight: Focusing on having more veggies, fruits, and plants in general should naturally help you consume fewer calories, Cording says. And the lower your calories intake, the more weight you'll lose. There’s also data to back this up: One review found that followers of the flexitarian diet had lower BMIs than people who ate meat more often.
A plant-forward diet may reduce your risk of heart disease, cancer, and type 2 diabetes. Because plants have essential nutrients, vitamins, minerals, and antioxidants, they boost your immune system and keep your cells going. Plant-based meals are also usually high in fiber but low in sugar and fat, which can charge your metabolism and lower your blood pressure, according to a 2016 Frontiers in Nutrition study.
The flexitarian diet has its perks, but there is limited structure. “In terms of a weight loss plan, it can be too flexible since it’s pretty vague and not necessarily telling you what kind of portions,” says Barrett. “You can be flexitarian but still eat a ton of calories, so it might be more helpful to think of it as a way of eating versus a weight loss plan.”
A sample three-day meal plan:
Day 1
- Breakfast: Oatmeal with nut butter, blueberries, and almond milk
- Lunch: Black beans, salsa, peppers, and onions, on a whole-grain tortilla, with raspberries
- Snack: Banana strawberry smoothie with yogurt
- Dinner: Baked lemon tilapia, basmati rice, and green beans
Day 2
- Breakfast: Fruit smoothie with protein powder
- Lunch: Turkey sandwich with avocado, tomato, lettuce, and cheese on whole grain toast, with a side of melon.
- Snack: Nut mix
- Dinner: Stir-fry tofu, with green beans, broccoli, water chestnuts, and sweet potato.
Day 3
- Breakfast: Greek yogurt with honey and muesli
- Lunch: Chickpea salad and mix greens in a high-fiber tortilla
- Snack: Apple and peanut butter
- Dinner: Lentil meatballs, chickpea pasta, Brussels sprouts, and marinara sauce
2. Volumetrics Diet
Volumetrics works just as it sounds—it focuses on the volume, or quantity, of foods, while encouraging you to eat nutrient-dense foods. The idea is to make sure you get full on foods that are high in fiber and water like fruits and veggies. So, you go by satiety cues, not the number of calories in your meals. "It emphasizes lower-calorie foods and healthy portion sizes,” Angelone says. “This diet also includes regular meals and snacks, so you don’t go hungry.”
How it helps you lose weight: “Focusing on healthy foods that will fill you up should help you consume less calories that will lead to weight loss,” Gans says. One study concluded this is definitely a good method to try: There was a clear connection between eating low-calorie, nutrient-dense diets and weight loss.
Since fruits and vegetables are the MVPs in this eating plan, you are consuming loads of vitamins, minerals, and antioxidants. Research shows this protects against nutritional deficiencies and gives an extra hand to your immune system, especially during cold and flu season.
While the diet emphasizes filling up on low-carb foods, the restriction of healthy fats can be a downside, says Barrett. “There are healthy fats we need for heart health and to lower disease risk, and being too strict on those can be harmful.” To get your share of heart-healthy fats, Barrett suggests adding sunflower oils, nuts, seeds, and salmon to your meals.
A sample three-day meal plan:
Day 1
- Breakfast: Oatmeal, blueberries, and non-fat milk
- Lunch: Chicken vegetable soup and an apple
- Snack: Non-fat yogurt with a banana
- Dinner: Baked salmon with quinoa, cauliflower rice, and melon
Day 2
- Breakfast: Egg whites with spinach and whole-grain toast with jam
- Lunch: Bean soup and roasted broccoli
- Snack: Carrots and celery with non-fat dip
- Dinner: Grilled chicken, couscous, and asparagus
Day 3
- Breakfast: High-fiber muffin with raspberries
- Lunch: Mixed greens with oranges
- Snack: Fruit salad
- Dinner: Turkey chili with jasmine rice and spinach
3. WW (Formerly Weight Watchers)
WW has been around for ages, and the company has gotten a lot of props for its points-based approach to foods. You get a certain number of points each day and strive to eat foods that stick within that. “It’s more of a lifestyle approach,” Cording says. “They do a wonderful job in educating people on portion sizes and how to budget their food.”
The program also offers in-person and virtual meetings for you to share your journey with others in the WW community. You can also sign up for live coaching.
How it helps you lose weight: The accountability is helpful for losing weight, Gans says. “For some people, keeping track of their foods with a personal points program keeps them accountable and more likely to keep up with the diet,” she points out. Research has also backed up the diet’s effectiveness for weight loss. One study found that people were much more likely to lose 10 percent of their body weight over six months on WW than those who were not using the program.
Another benefit of WW is its holistic and realistic approach. Research demonstrates that focusing on a balanced diet can improve your mood and help minimize symptoms of depression or anxiety by emphasizing quality and quantity over restriction. Plus, since meals are point-based, you can still eat out or attend parties without having to worry. The program also offers in-person and virtual meetings for you to share your journey with others in the WW community. Plus, you can sign up for live coaching.
Counting points may be liberating for some, but it can be tiring for others, says Barrett. “Some people get tired of tracking or scanning points and get frustrated, so WW depends on your lifestyle,” she notes.
It's also important to be mindful of “saving points” for treats and knocking out points for more nutrient-dense foods. “You don’t want to get into a roll-over pattern, so think about what foods are fitting into your point schedule,” says Barrett Remember: Balance is key and everything in moderation.
A sample three-day meal plan:
Day 1
- Breakfast: Overnight oats with blueberries and non-fat milk
- Lunch: Turkey wrap with spring mix and salsa in a low-carb tortilla
- Snack: Popcorn and a clementine
- Dinner: Baked tilapia with red potatoes, broccoli, and melon
Day 2
- Breakfast: Eggs and spinach
- Lunch: Shrimp with quinoa and spinach
- Snack: Rice cake and peanut butter
- Dinner: Lemon chicken with quinoa and asparagus
Day 3
- Breakfast: Greek yogurt with fresh fruit and granola
- Lunch: Tuna salad stuffed avocado
- Snack: Yogurt and fruit smoothie
- Dinner: Turkey meatballs, zucchini noodles and marinara
4. Keto Diet
The keto diet is high in fat, moderate in protein, and low in carbs. By restricting your carb intake to less than 50 grams a day, this eating plan helps trigger ketosis, the process by which your body burns fat instead of carbs for energy. “People who lose weight on the keto diet are eliminating so many foods they were eating before and, by default, consume less calories,” Gans explains.
How it helps you lose weight: “This diet eliminates most carbs, which includes the foods people tend to eat too much of—bread, pasta, rice, crackers, chips, and pizza,” Angelone says. “Weight comes off quickly since the muscles have to use up the stored carbohydrates which hold water in the muscles.” Part of the initial weight loss is water weight, she notes. Just keep in mind that you’ll often need to stick with keto or a low-carb diet to sustain these results, Cording says—and that’s not for everyone.
Because there is an emphasis on less carbs, research shows that your body looks to fat sources within the body as the primary store of energy. As a result, your insulin and blood glucose levels become lower, which reduces the risk of heart disease, diabetes, cancer, and even stroke.
That being said, restricting your intake of fruits, vegetables, and complex carbs can negatively impact your immune health and digestive system. “Fruits and complex carbs are needed to supply nutrients and key vitamins to the body to function, and keto can be a hard lifestyle to sustain long term,” says Barrett. Too much protein and not enough fiber can also cause constipation, so it’s important to be mindful of your fiber sources, she notes.
A sample three-day meal plan:
Day 1
- Breakfast: Eggs with bacon and cheese
- Lunch: A Cobb salad with bacon, cheese, ham, turkey, and avocado
- Snack: Cucumber and pepper slices
- Dinner: Steak, cheese, tomato, and lettuce in a low-carb tortilla
Day 2
- Breakfast: Egg and cheese muffin cups with sausage links
- Lunch: Tuna with celery, red bell pepper, and mayonnaise
- Snack: Strawberries
- Dinner: Baked chicken with bacon, broccoli, and mushrooms
Day 3
- Breakfast: Keto bread with avocado and a fried egg
- Lunch: Spring green mix with chicken, cucumber, and cheese
- Snack: Beef jerky
- Dinner: Burger with cheese, avocado, lettuce, tomato, and keto bread
5. Vegetarian Diet
A vegetarian diet isn’t a guaranteed way to lose weight, but it can be helpful if you are a big meat eater. There are many different types of vegetarian diets, but most shun meat while allowing for things like eggs and dairy products with a heavy emphasis on plant-based foods.
“This diet eliminates fat-rich meats,” Angelone says. “Vegan diets further eliminate cheese and other high-fat dairy. This is especially effective for people who eat a lot of meat, burgers, and cheese.”
How it helps you lose weight: Just ditching meat won’t automatically make you lose weight—especially if you’re not replacing it with nutrient-dense and high-fiber foods to fill you up, Cording points out. But doing a vegetarian diet the right way can definitely lead to weight loss. One study found that people who were overweight and obese who followed a plant-based diet for six months lost about 26 pounds on average.
A vegetarian diet is also recognized as a way to reduce chronic illness like diabetes, heart disease, and cancer, according to Harvard Health, since plant-based meals are rich in essential nutrients like vitamin C, vitamin E, folic acid, potassium, magnesium, and fiber. Choosing fresh, high-fiber, whole foods also helps keep blood sugar steady and reduce cholesterol levels.
Similar to a flexitarian diet, a vegetarian diet can be too flexible for weight loss, says Barrett. “You want to branch out to other food sources for protein because sticking with a high-calorie or high-fat source like cheese is going to give you too many calories for weight loss,” she says. Try tofu, black beans, chickpeas, and plant-based meat for other protein options.
A sample three-day meal plan:
Day 1
- Breakfast: Avocado toast with tomato and mixed berries
- Lunch: Grilled cheese, tomato soup, and a side salad
- Snack: Hummus and carrots
- Dinner: A pizza with grilled vegetables and spring salad
Day 2
- Breakfast: Mushroom and spinach frittata with cheese on whole-grain toast
- Lunch: Bean salad and chickpea pasta
- Snack: Banana and peanut butter
- Dinner: Impossible meatloaf, roasted sweet potato, and Brussels sprouts
Day 3
- Breakfast: Overnight oats with blueberries and nut butter
- Lunch: A black bean burrito with chips and salsa
- Snack: Trail mix
- Dinner: Tofu stir-fry with mixed vegetables and brown rice
6. Mediterranean Diet
The Mediterranean diet is based on the lifestyle of people who live in the Mediterranean region, which includes Greece, Italy, Portugal, and Spain. It’s big on plant-based foods and whole grains, along with healthy fats (think: avocados, fish, and nuts). The diet also allows for a glass of red wine day, but recommends that followers limit red meat.
How it helps you lose weight: At its core, the Mediterranean diet is designed to help followers be healthier. But research has found that people on the diet can lose up to 10 percent of their body weight over 12 months. “It’s more of a lifestyle, and very much about daily habits with what you’re eating,” Cording says. “It’s also good for satiety and emphasizes walking and activity as part of the diet.”
In addition to weight loss, research shows the Mediterranean diet optimizes heart health, manages blood sugar levels, and lowers the risk of Alzheimer's or dementia. By reducing added sugars and processed foods, you minimize your consumption of saturated fats, which are linked to high cholesterol and chronic illness. Plus, since you fill up on vegetables, fruits, legumes, nuts, and olive oil, you're taking in tons of vitamins, minerals, and anti-inflammatory antioxidants.
While fruits and veggies galore sound great, it can be pricey, says Barrett. However, frozen fruits or vegetables are perfectly okay for a more cost-friendly option, and it’s helpful to have frozen options in a pinch.
Another potential con is drinking too much red wine. “If you’re not a drinker, you don’t have to start drinking red wine for the diet to be successful. But if you do drink, watch your consumption because it’s going to add more calories,” explains Barrett.
A sample three-day meal plan:
Day 1
- Breakfast: Greek yogurt, granola, blueberries, and nuts
- Lunch: Lemon chicken with Greek salad on whole wheat pita
- Snack: Hummus and fresh vegetables
- Dinner: Salmon with vegetables, quinoa, and berries
Day 2
- Breakfast: Omelet with feta and spinach, fruit, and whole wheat toast
- Lunch: Pita with hummus, falafel, and tomato
- Snack: Mixed nuts
- Dinner: Chicken kabobs, red pepper, onions, and jasmine rice
Day 3
- Breakfast: Kale with butternut squash, wheat toast, and fruit
- Lunch: Salmon, spinach, and brown rice
- Snack: Fresh fruit and yogurt
- Dinner: Shrimp with olive oil, broccoli, mushrooms, and bean pasta
7. DASH Diet
The Dietary Approaches to Stop Hypertension (DASH) diet was originally created to help people lower their blood pressure. It zeroes in on fruits, veggies, low-fat and non-fat dairy products, and low-sodium foods, while minimizing saturated fat and cholesterol. “This program is a well-balanced diet plan,” Gans says. Cording says she’s also a big fan, noting that it’s really similar to a Mediterranean diet.
How it helps you lose weight: “By following this diet, you will eat so much plant foods that you won’t have much room for other foods like high-fat meats and cheeses,” Angelone says. Research has also found that it can lead to weight loss: One study of adults with obesity found that those on the DASH diet lose weight and decreased their body fat—and lowered their blood pressure.
There’s a reason the DASH diet was named a top overall diet in 2022 by the U.S. News & World Report because not only does it lower hypertension (which over half of U.S. adults have, according to the CDC) but research also shows it reduces cholesterol levels and ultimately minimizes risk of heart disease, stroke, heart failure, and kidney disease. Eating less sodium and cutting back on added sugar also has major perks for longevity.
Low sodium intake is the goal, but it can be challenging since there are often unknown levels of added salt in non-home cooked meals, says Barrett. “You have to be vigilant about the sodium content of the prepared foods and meals eaten out.”
To combat this, it’s best to prepare your own meals, but this can be difficult depending on your lifestyle. The DASH diet can also be challenging for those with lactose intolerance or food allergies since dairy is one of the main food groups, adds Barrett.
A sample three-day meal plan:
Day 1
- Breakfast: Overnight oats with salt-free nut butter and blueberries
- Lunch: Grilled chicken with spinach salad, vegetables, and low-salt crackers
- Snack: Yogurt and fruit smoothie with salt-free nuts
- Dinner: Salmon, broccoli, whole wheat couscous, and mixed berries
Day 2
- Breakfast: Bran muffin, banana, and non-fat milk
- Lunch: Turkey meatballs with whole wheat pasta, roasted cauliflower, and no-added salt marinara
- Snack: Apple with salt-free nut butter
- Dinner: Turkey chili, broccoli, and brown rice
Day 3
- Breakfast: Hard boiled eggs, whole wheat toast, and an apple
- Lunch: Grilled chicken sandwich with lettuce and tomato
- Snack: Walnuts and strawberries
- Dinner: Crockpot chicken, red potatoes, and green beans
8. Atkins Diet
The Atkins diet is similar to keto in that it’s very low-carb, Cording says. Followers are encouraged to limit their carb intake—which includes limiting high-starch veggies and high-sugar fruits—and focus on foods that are rich in nutrients and fiber. “You’re encouraged to eat fat, and people can get excited that they can have certain foods that are considered ‘off-limits’ on other diets,” Cording says.
How it helps you lose weight: Limiting carbs also means weeding out a lot of processed foods, Angelone says, including snacks like chips and crackers, along with cereal, bread, pasta, and rice. “Some initial weight loss is water, as the body has to use up some carbs, which hold onto water in muscles,” she says. But, like the keto diet, you really need to continue to limit carbs in order for the weight loss to be sustainable, Gans says.
Similarly to keto, the Atkins diet targets diabetes, heart disease, and high blood pressure prevention because studies show Atkins dieters reduce their levels of triglycerides.
On the other hand, because carbs are eliminated early in the diet, some people may experience headache, dizziness, weakness, fatigue, and constipation, says Barrett. “Your body needs some carbs, so if you went from eating a lot to then none at all, it can cause you to ‘crash.’” Up your nutrient and fiber intake to manage these adverse symptoms, she explains.
A sample three-day meal plan:
Day 1
- Breakfast: Eggs, bacon, and tomato
- Lunch: Burger with cheese, avocado, and spinach salad in a low-carb wrap
- Snack: Cheese and turkey roll up
- Dinner: Steak, Brussels sprouts, and cauliflower
Day 2
- Breakfast: Eggs, cheese, and sausage cups with tomato
- Lunch: Chicken, tomato, and mix greens in a low-carb tortilla
- Snack: Mixed nuts
- Dinner: Salmon, wild rice, mix greens, and bell peppers
Day 3
- Breakfast: Steel-cut oats, berries, and nut butter
- Lunch: Italian sausage with greens and marinara over whole wheat pasta
- Snack: Hummus and carrots
- Dinner: Pork on whole wheat bun with no-sugar coleslaw and acorn squash
9. South Beach Diet
The South Beach Diet focuses on eating foods with a low glycemic index, meaning they won’t make your blood sugar spike. The diet is low in carbs and high in protein and healthy fats, but it’s not strictly low carb. “This diet is based on eating plenty of non-starchy vegetables, fish, eggs, chicken and turkey, and nuts but full-fat dairy,” Angelone says.
How it helps you lose weight: Limiting your carb intake—especially if you usually eat a lot of it—can definitely lead to weight loss. “It’s also big on maintaining stable blood sugar, which can help curb impulsive snacking,” Cording says. The diet also encourages a lot of cooking at home—and that can lower the risk that sneaky sources of calories will make their way onto your plate, she adds.
Like many other diet plans that are low in carbs and high in protein and fat, the South Beach Diet can lower cholesterol levels, which positively impacts heart health, according to a 2019 study.
On the flip side, this diet can be very restrictive in the initial carb-cutting phase, and there is no instruction on when to add healthy carbs back into your meal plan. “You want to learn how to add in carbohydrates in a healthy way so that you maintain the weight loss or continue to lose weight,” says Barrett. Not all carbs are equal and learning to incorporate complex carbs into your diet can be beneficial in the long run.
A sample three-day meal plan:
Day 1
- Breakfast: Eggs, ham, and spinach
- Lunch: Grilled chicken and vegetables
- Snack: Cottage cheese and celery sticks
- Dinner: Salmon, roasted eggplant, and brown rice
Day 2
- Breakfast: Spinach and egg white cheese cups with tomato and bacon
- Lunch: Sirloin burger with low-fat swiss cheese and bean salad
- Snack: Cheese and blueberries
- Dinner: Pecan-crusted trout and grilled asparagus
Day 3
- Breakfast: Omelet with smoked salmon and tomato
- Lunch: Tuna over a bed of lettuce and cucumber
- Snack: Pistachios
- Dinner: Roasted chicken with zucchini and bell peppers
