It seems like just about every month there’s a new fad diet every celeb and food blogger is raving about on Instagram. (Ahem, Revenge Body’s Khloe Kardashian.) So we decided to check in with two experts — Heather Mangieri, MS, RDN, CSSD, LDN, spokesperson for the Academy of Nutrition and Dietetics, and Liz Barnet, a Nutrition and Fitness Coach in New York City — to help unwrap the pros and cons of the biggest weight loss diets out there.
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The Pros and Cons of 6 Popular Weight Loss Diets
1. Whole Food Diets
Whole 30 is a short-term plan designed to help dieters refresh their eating habits, while the Paleo diet is a very similar program meant to be a long-term approach to eating. Both diets eschew grains, legumes, dairy, processed foods of all kinds and alcohol. They also call for eating naturally raised meat, vegetables and some fruit. Paleo allows natural sweeteners, like honey, while Whole 30 forbids any form of added sugar, as well as Paleo-friendly recipes that are healthier alternatives to non-approved foods.
Pros: Overall, Mangieri and Barnet agree that whole food diets are some of the best fad diets out there. They help eliminate problem foods that may fuel cravings, unhealthy eating habits and even digestive distress. Most importantly, these programs tend to promote the balanced diet that most experts consider ideal for health. For example, says Mangieri, “We know that diets rich in fruits and vegetables help fight disease.” Barnet adds, “You’re going to get a lot more nutrition from the food [compared to processed diet foods], and they tend to be more satiating.”
Cons: Making the switch to a whole food diet won’t be a cakewalk (in fact, there probably won’t be any cake at all). You’ll also have to do your homework, Mangieri says. “There’s a lot of focus on what shouldn’t be included and not enough focus on what must be included to meet our daily needs.” It’s possible to get enough essential nutrients, she says, but you’re going to have to eat a lot more fruits and vegetables than you realize or consume supplements. While processed foods are demonized, she explains that these ingredients often have vitamins that have been added to fortify foods so that we meet our nutritional needs.
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If you follow Kylie Jenner, Vanessa Hudgens or Hilary Duff, you’ve probably heard them wax poetic about teatoxes. These programs, which are marketed by several brands, generally consist of morning and evening tea blends that promise to help shed pounds (in combination with a healthy diet and exercise). The tea blends usually include the laxative ingredient, senna. Senna has been used to help treat constipation, but doctors advise using it only short-term.
Pros: “Herbs and teas definitely can have positive effects on your health,” says Barnet. “Certain teas can be helpful for digestion or stress,” she notes, such as peppermint or ginger for digestion and chamomile for de-stressing. Barnet also points out that the ritual of drinking tea every evening, for example, can be helpful to our overall well-being (sleep routines included), and for those reasons could help your weight loss efforts.
Cons: Our experts agree that adding a teatox to your diet is not going to miraculously help you lose fat. “The idea that it’s flushing your system or detoxing is just not true,” says Mangieri. While a diuretic ingredient in the tea could cause you to lose weight, that weight is essentially just water — not fat — and will spring right back when you stop teatoxing. The amount of the diuretic in these teas is unlikely to be dangerous in their prescribed concentrations. But if you go overboard, it could pose a health threat, Mangieri says.
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3. Soup Cleanses
Soup cleanses are the latest alternative to juicing. Like juice cleanses, a soup cleanse is intended to help the body clean out toxins and jump-start weight loss. But unlike juicing, soup cleanses have naturally more fiber and other nutrients, since soups are made with whole vegetables and fruits. The soups may also include grains and legumes, so you won’t get hungry.
Pros: “If we’re talking about soup cleansing versus juice cleansing,” says Barnet, “you’re going to have more fiber, potentially more protein, and more fat on a soup cleanse. It’s closer to eating real food as far as nutrition and satiety.” The nutritional value of a particular cleanse will depend on the exact program, but it’s possible to meet your body’s nutritional needs. For dieters who prefer to simply be told what to eat and when, she says, soup cleanses can work.
Cons: Like juice cleanses and teatoxes, any weight loss you see on a soup cleanse is going to be water weight, Barnet warns. Consuming soups doesn’t teach you the behavioral changes you’ll need to learn to lose weight long-term. Studies have even shown that satiety is linked to chewing, so even if you’re getting enough food, a soup cleanse can leave you feeling hungry.
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4. Fasting Diets
The common thread among intermittent fasting methods, The 8-Hour Diet, Leangains, The Fast Diet and the 5:2 Diet? Dieters are limited in the days or times when they can eat. For example, those who follow Leangains will fast 14-16 hours a day and tailor meals to their workout schedule. On the other hand, people following Eat Stop Eat will fast for a full 48 hours each week, while consuming a normal diet during the other days.
Pros: According to research, “Fasting can help with things like longevity and even disease prevention,” says Barnet. Avoiding eating at certain times may also draw your attention to mindless eating. “In terms of weight loss … if you’re used to a late-night snack you’re going to end up eating less [when fasting],” says Barnet. Daily Burn 365 trainer Gregg Cook relies on intermittent fasting to help him regulate blood sugar levels and maintain muscle mass.
Cons: “We know that restricting food causes you to think more about food,” says Mangieri. So if you’re already having trouble controlling what, when and how much you eat, fasting can make that problem worse. Not only that, Mangieri says, “There is never a time when depriving your body of nutrients is beneficial. When you’re fasting, that’s essentially what you’re doing.” Barnet adds that fasting “can promote binge eating and focusing on calories versus quality of food.”
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5. Low-Carb, High-Fat Diets
Low-carb, high-fat diets (like the Always Hungry Solution, Atkins and the Ketogenic Diet) promise to help you lose weight, stay energized and build or maintain muscle mass — all without going hungry. Creators of these diets say the secret is in starving the body of “easy energy” (carbs) and training the body to metabolize fat instead. While Atkins may be the first and most well-known of these approaches, there are now a variety of different plans that recommend different fat-protein-carb ratios.
Pros: “Carbohydrates are easy to overeat,” says Mangieri, so drastically reducing your carb intake can help you reduce calories, leading to weight loss. She also notes that these diets tend to promote lean protein intake at every meal, which is a good choice. Barnet adds, “There is scientific backing that if you increase your fat consumption and decrease carbs, over time your body can learn to use fat as fuel.” Research has also shown that fat is an excellent energy source for the brain. If you do well with hard and fast rules, says Barnet, a high-fat diet can work for you.
Cons: “Carbohydrates include vegetables, fruit, milk, yogurt and whole grains,” says Mangieri, “They have the vitamins and minerals needed to meet our daily requirements.” And if you’re looking to lose body fat by burning lots of calories, you need carbs to fuel your workouts. Not to mention, it’s incredibly easy to overeat high-fat foods, like avocados and nuts, which have a ton of calories.
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6. Carb Cycling
Carb cycling is the process of alternating daily between a high-carb and low-carb diet. The promise is that you’ll see the weight loss benefits of a low-carb diet, but keep your body fueled with carbs on the days you need it. Carb cycling also helps keep your metabolism revved up.
Pros: When you expend a lot of calories exercising, carbohydrates are an ideal way to quickly and easily fuel your workouts. If you were following a very low-carb diet, for example, it would be important to add carbs when you’re doing a lot of cardio.
Cons: “There’s no evidence to support this for weight loss at all, whatsoever,” says Mangieri. Research has yet to prove that alternating your carb intake actually impacts your metabolism. She adds that an approach like this overcomplicates things for non-athletes who are just doing a standard hour-long workout at the gym. Mangieri also notes that most everyday fitness fans put too much emphasis on “recovery nutrition.” Instead, Barnet suggests cooking up a big batch of carbs, like sweet potatoes, at the beginning of the week and eating a little more carbs on days that you have a big cardio spend.
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Where to Draw the Line
While we would all love a magic bullet that’s going to help us drop the extra pounds in a flash, finding the right eating plan is highly personal choice. “A lot of the diets out there are promoted as if they’ll work for everyone,” says Mangieri. “What works for one person is not going to work for everyone.” The real secret is finding the program that you can stick to for an extended period of time — or even better, for the rest of your healthy life.