10 Popular Diets That Actually Work

healthy lunch plate with sweet potato, beet, avocado, and onions

In the world of health and wellness, there's nothing more confusing than dieting. Sure, we're told time and time again the only thing that really works is diet and exercise (and patience). Yet, we're still willing to listen and attempt every new fad diet in hopes that it's the one that changes everything. (Usually, it's not). "The best diet is one that caters to your unique needs, preferences, metabolisms, and lifestyles. It's important to respect your bio-individuality and follow an approach that makes you feel the best," says registered dietitian Lisa Moskovitz.

So we decided to declutter our minds and find out once and for all which popular diets really work. We put 10 diets to the test and reached out to a number of dietary experts, including emergency medical physician Cassie Majestic, MD, Moskovitz, and certified sports and clinical nutritionist Cara Clark for more advice. Read on to learn about the 10 diets we found that work. Remember, any diets that cut out entire food groups or are restrictive are not safe. Instead, dietitians recommend diets that focus on whole foods and eating when you feel hungry.

01 of 10

Mediterranean Diet

Mediterranean diet
Gabriel Bucataru/Stocksy United

The Mediterranean diet is inspired by the dietary habits of, well, the Mediterranean. It promotes fresh, non-processed foods, including vegetables, olive oil, fish, and chicken. But you have to stay away from processed foods, salt, red meat, and saturated fat.

The most palpable pro is that consumption of red wine is included in the program, along with the fact that the majority of the allowed foods are associated with a potential for preventing heart disease, diabetes, high blood pressure, and obesity.

Shereen Jegtvig-Lehman, MS, an evidence-based nutrition specialist and the co-author of Superfoods for Dummies, speaks to the ease of the diet: "The Mediterranean diet includes a lot of delicious food and has a good variety. Of course," she admits, "if you need to lose weight, you'll still need to count calories."

Clark chimes in, "This has been around since I’ve been teaching nutrition, but I see it gaining popularity in the medical world, which always signifies what we nutritionists will see people requesting. I love that this is rich in vegetables, fruits, nuts, seeds, oils, whole grains, and fish. It’s moderate on dairy, poultry, and eggs and rare on meat, and it’s unprocessed and full of nutrient-dense foods. These foods work well in our bodies, providing us essential nutrients for heart health as well as many other organs in the body. It’s preventative medicine at its finest."

02 of 10

5:2 Diet

Berry Breakfast pizza
Leah Maroney

The 5:2 diet is most popular in the United Kingdom, Australia, and Sweden and consists of two days following a restricted calorie fast and five days of normal eating. For five days out of the week, you can continue your normal diet of about 2000 to 2500 calories. While there aren't any preset food restrictions, you're instructed to fast for two days out of the week. On those days, you have to adhere to a 500-calorie-per-day regimen (600 calories for men).

The diet is far easier to stick to than most because you only really have to change what you're eating for two days out of the week. Plus, fasting's benefits include things like improving blood pressure, cholesterol levels, and metabolic rate.

While, technically, fasting for two days can be just as effective as continuous calorie restriction, it can also severely impact your energy levels and lead to nutrient deficiencies. If you plan to work out, you'll have to do so on days when you're not fasting.

"Calorie counting is also a popular approach that can be effective. However, if you find yourself obsessing, stressing, or over-thinking what you're eating, then it might be causing more harm than good," says Moskovitz.

Meryl Pritchard, a holistic nutritionist and founder of organic meal delivery service Kore Kitchen, weighs in: "If done right, fasting can be very beneficial to your health," Pritchard says. "It allows your body to repair and rejuvenate. This is what your body does when you're sleeping. If you're constantly eating, your body doesn't have the opportunity to do this." But, she explains, "Most people don't even know what a calorie is, let alone how to measure it," she says. "What we tell our clients is that it's really not about the quantity of calories—you should focus more on the quality."

03 of 10

Paleo Diet

Ketogenic Foods

The Paleo diet claims that modern foods have evolved much faster than our bodies, causing problems and illnesses. The regimen promotes eating foods that early Paleolithic humans might have eaten. On this diet, you can eat grass-fed meats, seafood, fresh fruits and vegetables, eggs, nuts, seeds, and healthy oils, including coconut, avocado, olive, and walnut. You can't have cereal grains, legumes (including peanuts), dairy, refined sugar, refined vegetable oils, potatoes, processed foods, or salt.

Your diet will be cleaner and certainly contain fewer processed foods, and because it's high in protein, you'll feel full longer. The diet does lack certain nutrients, including calcium and vitamin D. Plus, it can be particularly difficult for vegetarians, as beans aren't allowed.

Jegtvig-Lehman says, "Strict rules can make dieting easy at first, but it gets harder in the long run. Because Paleo is popular, it can be made easier with available Paleo-approved snacks and recipes."

04 of 10

Alkaline Diet

Mushroom Soup in a Cup
Sam Stowell/StockFood Creative/Getty Images

An alkaline diet involves eating alkaline foods to keep your body's pH levels between 7.35 and 7.45 (14.0 is pure alkaline, 7.0 is neutral, and 3.0 is acidic), avoiding foods that become acidic once broken down. The diet claims to improve memory and boost energy levels while preventing headaches and bloating.

You can have fresh fruits (including citrus), vegetables, nuts, and legumes on the diet. However, you can't have any wheat, pasta, meat, fish, shellfish, dairy, tea and coffee, sugar, or alcohol.

You'll increase your vegetable and fruit consumption, along with a drastic reduction in sugar and fat intake. "I like that this diet is high in fruits and vegetables," says Jegtvig-Lehman. But "restrictions are difficult to follow, and this one is no exception: no gluten, little to no meat, no processed foods, and no alcohol or caffeine." Increasing your fruit and vegetable intake is highly beneficial for your health, but restrictiveness may reduce the effectiveness of this diet. However, if you already adhere to a plant-based diet, it might be an easier transition.

05 of 10

WW (Weight Watchers)

Weight Watchers stock down 40% this year
Corbis via Getty Images / Getty Images

Formerly known as Weight Watchers, this diet has been around for over 50 years but went through a major rebranding in 2018. This diet uses a simplified calorie counting system in which your height, age, weight, and goals are all taken into consideration.

Each food has a specific smart point attached to it and, depending on your goal; you are allotted a specific number of points per day. While there are no major restrictions, it can be hard to keep track of food intake and the points you're eating. According to Clark, "They’ve actually made some positive strides in the last few years developing their program more based on real foods and teaching the science of nutrition and not just counting. It’s built on a counting system, which creates some freedom in choices."

"It also includes eating a balance of macronutrients, rather than completely restricting them, like some diets that have been popular in the last few years. I like changes they’ve made to it and think it could be a great fit for a lot of people looking for a full overhaul."

06 of 10

Flexitarian Diet

Quinoa Salad - How to Eat Vegan for Cheap
Grateful Grazer

Flexitarian Diet stands for a flexible vegetarian in which 80 percent of your diet is plant-based, and 20 percent is from animal protein. This way, you're still reaping the health benefits of a plant-based diet, such as lowering your rate of heart disease, diabetes, and cancer—while still getting to enjoy the foods you love.

Clark agrees, "I actually see this one gaining a lot of popularity this year. Partly because it’s vague and is open to interpretation. It’s pretty much the way I teach nutrition in the sense that 80 percent of our diets should be plant-based, with 20 percent coming from animal protein. I like the idea of having flexibility with your diet because it instills the lifestyle element to it. If it’s flexible, it’s more manageable. If it’s manageable, it’s more sustainable. If it’s sustainable, then it’s not a diet, after all. I’m foreseeing a lot more people just making healthy habits in a flexitarian way this year."

07 of 10

Atkins Diet

Ketogenic Diet

Atkins has been trending for years; even Kim Kardashian West herself is a fan. Clark says, "The good thing about some trendy diets is that it gets people to refocus on health. The only thing that all the trends and lifestyles agree on is more veggies!"

Atkins is no exception. A low carb regimen dating back to the '90s, this diet encourages you to fill up on lean protein, good fats, as well as low-carb, nutrient-rich fruits and vegetables. On this diet, it's recommended to limit carbohydrate intake. A typical day could include an omelette for breakfast, salad with protein for lunch, and zucchini pasta with a lean protein for dinner. Yum!

08 of 10

Whole 30

whole30 soup
Food Faith Fitness

Whole 30 is a diet that focuses on whole, unprocessed foods for an entire 30-day window. This diet encourages cutting out multiple food groups, including grains and legumes, alcohol, and added sugars, to emphasize eating real food without processed ingredients. It's a great choice for anyone looking for a full reset. This diet is similar to the way Majestic eats in her everyday life. “Lots of colors and balance is key. I try to fill my diet with more colors and less processed foods."

“You will quickly notice how easy it can be to add whole foods to your meals without much effort. I also like to recommend label reading. Learn what preservatives are and how they are disguised in our foods. Try to avoid them if you’re able to,” says Majestic.

09 of 10


Vegan banana ice cream
Sohadiszno / Getty Images

Going vegan? This plant-based diet has gained lots of popularity in the past few years. It includes cutting out all animal products, which means dairy has to go, too. To ensure a healthy diet, vegans should consume meals that contain protein, carbohydrates, vegetables, and healthy fats. The vegan diet poses risks of nutrient deficiencies if not done correctly, including vitamin B12, vitamin D, iron, calcium, and zinc. It may be a good idea to supplement this diet with a multi-vitamin to ensure you are getting all of the nutrition that you need. Tofu and nut butters are a must, and make sure you study up on how to properly consume protein on this diet. Lastly, Moskovitz reminds, "enjoying your favorite foods is paramount to long-term success, no matter which diet plan you follow."

10 of 10

Intermittent Fasting


Intermittent Fasting has gained a lot of popularity in the past few years. The idea is that you're going long periods without food but still not depriving yourself. This way, your calorie intake is limited, but you still don't feel restricted. “A calorie deficit can be necessary to lose weight, but this largely depends on activity level as well. I’m not a huge fan of counting calories obsessively, but if the goal is to lose weight, it’s simple," says Majestic. "Calories in must be less than calories out. Most people don’t understand that this can be done without starving yourself or eating foods you hate! I don’t believe in calorie deficits on a regular basis, once you’re at a healthy, goal weight.”

Intermittent fasting can lead to weight loss but also increased energy levels and stress reduction. To do so successfully, you want to follow a specific eating pattern. Many people choose to fast for 16 hours, followed by a window of eight hours of eating. The idea is that when your body is digesting food, you're not burning fat. In order to reach the window of fat burning, one needs to allow the body time to completely digest before eating their next meal.

Article Sources
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  4. Kahleova H, Levin S, Barnard N. Cardio-metabolic benefits of plant-based dietsNutrients. 2017;9(8):848. doi:10.3390/nu9080848

  5. American Academy of Family Physicians. Vegan Diet: How to Get the Nutrients You Need. Updated July 31, 2020.

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