The 9 Biggest Fad Diets to Have on Your Radar: Are They Healthy?

It’s easy to want a quick fix when it comes to weight loss. That’s why fad diets have become so popular.

While true fad diets aren’t something you want to dive into, these often promise quick results that usually aren’t sustainable, there are also eating plans that simply have become more and less popular over time. Some, like the Mediterranean diet, have staying power, while others are a huge thing for a short period of time, before quickly fading away.

If you’re looking for a new eating plan while trying to lose weight, it’s a good idea to double check to make sure what you choose lines up with your needs and is something you can sustain over time.

But if you’re looking for a popular eating plan that’s buzzy right now, you may have heard of these options. They’ve gotten plenty of attention and earned fans in the process. Each has its pros and cons, with some having more of a fanbase among experts than others. Nutritionists break them down.

Macrobiotic diet

The macrobiotic diet encourages followers to focus on eating whole foods over processed foods, explains dietitian Jessica Cording. It also encourages followers to lead a slower lifestyle and to be mindful about eating. The diet is rigid, with meals that focus on having whole grains, fruits, and vegetables. It also focuses on avoiding foods that contain “toxins,” Cording says.

Pros: The macrobiotic diet “includes a variety of whole, minimally processed foods,” says nutritionist Sonya Angelone. She also likes that the eating plan “encourages positive eating behaviours like mindfulness when eating.”

Cons: “There is potential with this diet, but it can be very restrictive,” Cording says. She points out that followers are encouraged to avoid nightshade vegetables, like potatoes, peppers, and tomatoes. “While some people might feel better without those, not everyone needs to avoid nightshades,” Cording says. “This can cause people to narrow their food options down too much.”

The macrobiotic diet can also be low in certain key nutrients like vitamin B12, calcium, and iron, Angelone says.

South Beach

The South Beach diet was created by cardiologist Dr Arthur Agatston, originally as a way to help patients with conditions like heart disease and type 2 diabetes, Cording says. South Beach encourages followers to focus on lean proteins, low-fat dairy, whole grains, vegetables, and fruit. It follows different phases, including an original restrictive phase that’s designed to get rid of cravings for sugars and starches, a second phase where you add back in some whole grain breads, fruits, and vegetables, and a third maintenance phase, Cording says.

Pros: “After the beginning phases, it encourages well-balanced eating that includes plenty of fruits, veggies, and 100% whole grains, plus daily exercise,” says dietitian Keri Gans. “This diet provides good variety in a structured approach,” Angelone says. “This allows users to gradually learn to adopt better eating habits.” She also likes the balance of proteins, complex carbs, and healthy fats.

Cons: The initial phases are “pretty restrictive,” and that can be difficult for some people, Angelone says. “It is lower in carbs initially so it may be accompanied by fatigue or headaches,” she says. “Planning is required so it may not be very convenient for some.”

Weight Watchers

Weight Watchers uses a points system to help followers learn to eat healthy and in moderation, while focusing on foods they enjoy. The company also provides virtual support meetings for followers.

Pros: “It’s very much about prioritising what indulgences are worth it to you,” Cording says. “It gets people to think about portion sizes and how to “budget”, when to indulge, which is an element of mindfulness that I appreciate.”

The points system also allows for flexibility with foods, Angelone says. “The track record of success is better than for most other programs,” she says. “The support system of in-person or online meetings helps build a community for support.”

Cons: Some of the foods in the points system are controversial with dietitians. “Some nutrient-dense foods are given a higher points value and people miss out on them because of the higher points,” Cording says. “Some people also tell me that they get tired of counting points.” When people stop the program, they often gain the weight back, Gans says.

Mediterranean diet

This eating plan is a consistent favourite of dietitians and health experts. It focuses on heart-healthy foods enjoyed by people in the Mediterranean region, like fish, nuts and legumes, vegetables, and fruits. It even makes room for red wine in moderation, Cording says.

Pros: Angelone calls the Mediterranean diet a “healthy diet for life” that people can maintain after they lose weight. “It includes a wide variety of food choices, including healthy fats and seafood but limited sodium, saturated fats, and refined carbs,” Angelone says.

“It is also a good choice if you have other health conditions like diabetes, heart issues, joint or bone health concerns.” Angelone points out that it’s easy to follow and family-friendly, too.

The Med diet is so well researched that it can't be classed as a fat diet; it has been shown to actually work for health and longevity. And yes, it can work for weight loss, too. Studies have found that following either a traditional Mediterranean diet or a low-carb version of it can result in weight loss of about 5–10% of body weight over 12 months. And another study shows that that weight stays off. 

Cons: The Mediterranean diet doesn’t include overly processed and fast foods, which can make it hard for people who don’t have time to cook or plan meals, Angelone says. Still, “the only difficulty could be for those individuals who really need a solid plan with stricter guidelines to follow,” Gans says.

Learn more about the Mediterranean diet.

Zone

The Zone diet is big on balancing carbs, protein, and fat. Users follow a 30-30-40 breakdown of macronutrients, aiming to get 30% of their kilojoules from protein, 30% from fat, and 40% from carbohydrates, Cording says. Followers are also encouraged to eat within an hour of waking up and to have a snack before bed, Cording says.

Pros: Cording gives the Zone the thumbs up for emphasising blood sugar balance. “It emphasises eating consistently throughout the day and I think that’s positive,” she says. “No foods are totally off-limits.” Angelone also likes that the diet focuses on minimally processed foods.

Cons: Eating within an hour of getting up and having a snack before bed isn’t a good fit for everyone, Cording says. Others can find it tough to stick with the 30-30-40 rule, she says. “I’ve had people tell me that they don’t like feeling like they can’t even have a snack without thinking about the ratio,” she says.

Atkins diet

The Atkins diet has changed over time to be a little more healthy than its bacon- and steak-heavy original version. The eating plan focuses on balancing lean proteins, fat, and healthy carbs, Cording says.

Atkins recommends that followers minimise refined flour and sugar, although it also restricts whole grain foods until you reach the maintenance phase. Atkins is one of the original low-carb diets, Gans says. “Its four-phase program can be extremely restrictive at the beginning, especially with phase one allowing less than 20 grams of carbs per day, she says.

Pros: “Weight loss is fast in the initial phases with little hunger due to the high fat and protein content of the diet,” Angelone says, noting that it “may help with blood sugar problems.”

Cons: “By phase four, the diet becomes much more inclusive of carbs; however, too many people never leave phase one, making the diet too difficult to follow,” Gans says.

The low-carb diet may also cause people to have fatigue, keto breath, or sluggishness while their body adapts to the plan, Angelone says. “It may also lead to nutrient deficiencies due to food restrictions,” she says, noting that “the low fibre diet may even lead to constipation.”

Raw food diet

The raw food diet tells followers to focus on foods that are cooked no more than 47°C, Cording says. The idea behind this is that cooking food will break down enzymes and get rid of nutritional benefits, she explains.

Pros: Angelone likes that this is a high fibre diet that can help promote good bowel movements and health. “It focuses on raw fruits and vegetables, which are nutrient-dense,” she adds.

Cons: This diet tends to be lower in protein and calcium, Cording says. “It’s also very restrictive,” she adds, noting that cooking can actually enhance the absorption of certain ingredients.

“This is not something that I encourage someone who is looking for a sustainable approach to healthy eating to follow,” Cording says. Cording also flags that the high fibre diet may cause people to have gas and stomach pains.

Paleo

The Paleo diet “promotes eating like hunters and gatherers,” Gans says. It has a strong emphasis on whole fruits and vegetables, nuts and seeds, and lean proteins. Paleo also encourages its followers to exercise regularly, Cording says.

Pros: Angelone likes the emphasis on whole foods, with minimal overly processed and refined foods. “For people with some sensitivities, whether autoimmune conditions, wheat, or rye sensitivities, I have seen Paleo work for some people,” Cording says.

Cons: Gans says Paleo is a little confusing. “While its premise is to consume only foods that were around during the Paleolithic era, it won’t dismiss a coffee run,” she says.

The diet also eliminates grains and dairy, which can cause people to feel low-energy, Angelone says. “It also may be hard to follow for a vegetarian since it isn’t really plant-based,” she says.

Keto

The Keto diet is an extremely high-fat, low-carb eating plan has been touted for its ability to help you shed major kilos, boost your energy, and possibly even improve your health overall. 

Pros: As with most very restrictive diets, the keto diet has been shown to aid in weight loss. This is likely due to the satiating effect of high-fat foods. When you feel full, you have less of an appetite and end up eating fewer kilojoules. But there's little evidence that any resulting weight loss is long term.

Cons: Unless you follow the plan strictly and stay in a state of ketosis, gaining that weight back is very likely. The keto diet isn’t kilojoule-restricted, but the types of foods you can eat are significantly restricted, meaning you’ll probably have a hard time sticking to it for the long-term. And keeping your body in what is basically a crisis state is not a viable long-term plan.

There's evidence the keto diet can hurt your relationship with food and has bad side effects, such as headaches, bad breath, and lack of energy (collectively referred to as keto flu). Super low carb diets like this may even shorten your life, according to a large study from 2018.

Want to know about diets that work? Learn about the best diets for weight loss.