The New 90-30-50 Diet Plan That Has Taken Over Your TikTok

The new 90-30-50 diet seen all over TikTok makes a simple promise that seems too good to be true: You can lose weight not by restricting certain foods, but by eating a variety of healthy ones.

The creator and promoter of the diet, 29-year-old influencer Courtney Kassis, RDN, reportedly lost 15 pounds and dropped 2 percent body fat in two months by following her 90-30-50 plan, and has kept the weight off for over a year.

Followers of the 90-30-50 diet eat at least 90 grams of protein, 30 grams of fiber, and 50 grams of healthy fats each day. “Together, these nutrients work to increase metabolism, support fat-burning processes, promote satiety, balance blood sugar, and increase lean muscle mass — all of which support optimal health and weight loss goals,” claims Kassis in a video.

So, does that mean the 90-30-50 diet is a healthy way to lose weight?

While TikTok diet trends may not necessarily guarantee health, the 90-30-50 diet could be a keeper. The experts we talked to give the diet a thumbs-up — with a few caveats. Here’s what they had to say.

Carbs Aren’t Off-Limits in the 90-30-50 Diet

“The diet doesn’t appear to limit any food groups, which is in line with what we tell patients when they’re following any dietary plan,” says Suki Singh, MD, family medicine and obesity medicine physician at Henry Ford Health in Michigan. “Diets that are very restrictive can lead to yo-yo dieting/weight cycling, which can negatively impact health.” Among other consequences, weight cycling can lead to weight gain and insulin resistance, according to an article in Journal of Obesity & Metabolic Syndrome. Balanced diet plans, however, are more likely to lead to long-term success, Dr. Singh says.

“Restrictive diets, like ones that eliminate carbs, are super unsustainable,” stated Kassis in a video. In the 90-30-50 method, the priority is protein, fiber, and healthy fats, but once these three nutrients are prioritized, carbs (ideally whole, unprocessed, low-glycemic sources) fit in, said the TikToker.

The 90-30-50 diet could be a healthy way to manage weight, says Julia Zumpano, RD, who works with the Cleveland Clinic. “The fundamental pillars of this plan are based on the sound nutrition advice of eating more protein and fiber, and less fat. That’s all great advice, but ‘one size does not always fit all,’” she cautions.

Ideally, a person would meet with a registered dietitian to be sure they are meeting their specific needs, adds Zumpano.

The 90-30-50 diet is new, and there isn’t any clinical data or research to show that this would result in weight loss for everyone — although on paper, it makes sense that people would lose weight on the plan, says Singh.

“The diet focuses more on protein, which always helps with the sustainability of weight loss,” says Singh. One historical study showed that a 20 percent increase in protein intake during a three-month maintenance phase after weight loss resulted in a 50 percent lower weight regain. Not only that, but the diet also includes fiber, “which can help people feel more full and eat less, along with healthy fats,” Singh says. “If a person focuses on those things while eliminating a lot of processed foods and sugary drinks, that will typically lead to weight loss.”

A protein goal of 90 grams would work for most women, although depending on age and activity level, it could vary somewhat, says Zumpano. According to a 2019 review in Nutrients, 1.2 to 2 grams of daily protein per kilogram of body weight can optimize health in physically active individuals, which would equate to about 88 grams for a 150-pound woman. By comparison, the Recommended Dietary Allowance (RDA) for protein is 0.8 grams of protein per kilogram of body weight.

Lean meats like chicken or fish are good sources of protein, Zumpano continues. Per the U.S. Department of Agriculture (USDA), one 4-ounce serving of raw, boneless chicken contains 136 calories. Similarly, the USDA lists a 3-ounce portion of whitefish at 114 calories. But non-meat eaters could meet that goal, too, Zumpano says, "especially if they eat dairy and eggs or use supplemental protein." Beans are also an excellent protein source, with 109 calories in a ½-cup serving, per the USDA. To achieve the protein goal more easily, Zumpano suggests including protein in every meal and snack.

Most People Don’t Get Close to 30 Grams of Fiber

The Academy of Nutrition and Dietetics suggests people eat between 25 and 38 grams of fiber per day, depending on their weight. But they estimate only 5 percent of Americans meet that goal.

“It’s refreshing to see a diet that focuses on fiber,” says Zumpano. And it’s really not hard to eat that much fiber if you follow a whole-foods diet that includes fruits, vegetables, legumes, whole grains, nuts, and seeds, she adds.

When buying items with whole grains, you should also screen the ingredient list to make sure there aren’t a lot of added sugars, says Zumpano.

Warning: If you’ve been eating very little fiber, amping up to 30 grams right away could leave you feeling gassy and bloated. Zumpano recommends starting with a goal of 15 to 20 grams of fiber per day at first. “Add 5 grams of fiber every three to four days until you reach the goal of 30 grams, and drink plenty of water to avoid being constipated [and gassy],” she says.

50 Grams of Healthy Fats Is in Line With Dietary Guidelines

Healthy fats play a vital role in good nutrition — they’re one of the three main nutrients the body needs, along with carbs and protein. Not only do they supply energy, but they also help with the absorption of certain vitamins from foods.

The Dietary Guidelines for Americans 2020–2025 recommends that no more than 20 to 35 percent of calories come from fat. If a person eats a 2,000-calorie diet, that means eating between 44 and 78 grams of total fat. The guidelines also suggest that healthy fats replace saturated fats for optimal heart health.

There are two kinds of healthy fats:

1. Monounsaturated fats (MUFA) include almonds, olives, olive oil, avocados, and canola oil.
2. Polyunsaturated fats (PUFA) include omega-3 fatty acids found in flaxseed, chia seeds, hemp seeds, walnuts, avocado oil, sunflower seeds, and pumpkin seeds.

While it’s possible to find healthy fats in ready-to-eat foods and baked goods, it’s less likely, says Zumpano. “You will need to seek out grocery stores and brands and do some research to make sure the foods are prepared or contain healthy fats such as avocado oil or olive oil,” she says.

If you decide the 90-30-50 plan is a good fit for you, Zumpano suggests using an app to keep track of the foods you eat and how many grams of protein, fiber, and fats are in your meals, snacks, and beverages.

 

Editorial Sources and Fact-Checking

• Rhee EJ. Weight Cycling and Its Cardiometabolic Impact. Journal of Obesity & Metabolic Syndrome. December 30, 2017.
• Westerterp-Plantenga MS et al. High Protein Intake Sustains Weight Maintenance After Body Weight Loss in Humans. International Journal of Obesity. December 22, 2003.
• Carbone JW et al. Dietary Protein and Muscle Mass: Translating Science to Application and Health Benefit. Nutrients. May 22, 2019.
• Chicken, Broiler or Fryers, Breast, Skinless, Boneless, Meat Only, Raw. U.S. Department of Agriculture. April 1, 2019.
• Fish, Whitefish, Mixed Species, Raw. U.S. Department of Agriculture. April 1, 2019.
• Beans, Black, Mature Seeds, Canned, Low Sodium. U.S. Department of Agriculture. April 1, 2019.
• Dahl W et al. Position of the Academy of Nutrition and Dietetics: Health Implications of Dietary Fiber. Journal of the Academy of Nutrition and Dietetics. November 2015.
• Most Americans Are Not Getting Enough Fiber in Our Diets. American Society for Nutrition. June 9, 2021.
• Dietary Guidelines for Americans 2020–2025. U.S. Department of Agriculture. December 2020.