Nutritionist Reacts to 90-30-50 Diet

By: Jeremy Fox, CNC, CPT – Published: October 24, 2023

The 90-30-50 diet has gone viral on social media, and its creator is claiming amazing weight loss results using this simple nutrition framework. So is this the real deal, or just another flash-in-the-pan fad diet?

As a nutrition expert and coach, I decided to dig deeper into the principles of this meal plan to see if studies and research back the claims. Read on to get the facts on the 90-30-50 diet!

What Is the 90-30-50 Diet?

Dietary Components

Fact-Checking Claims

90-30-50 Diet Example

The 90-30-50 Diet Method

The summer of 2023 saw the widespread popularity of the 90-30-50 diet method on TikTok, thanks to dietitian Courtney Kassis (@dietitianwithtwins). Her idea gained nearly 1 million views on the platform.

The 90-30-50 diet strategy involves targeting at least 90 grams of protein, 30 grams of fiber, and 50 grams of healthy fats daily.

In her video, Kassis asserted that her method produces excellent results for healthy weight loss. However, she also included a disclaimer stating that it is not a quick fix for rapid weight loss and that results may vary depending on individual factors.

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Components of the 90-30-50 Diet

In this section, I will elaborate on the three components of the 90-30-50 diet to better understand how it is implemented.

90 Grams of Protein

The first and most important aspect of the 90-30-50 diet is eating at least 90 grams of protein daily. Kassis suggests this is the minimum needed to facilitate muscle growth, maintain a healthy metabolism, and balance blood sugar levels.

30 Grams of Fiber

Consuming 30 grams of fiber is the next target of the 90-30-50 diet, according to Kassis. She recommends eating a lot of non-starchy vegetables to achieve this goal, which provides valuable micronutrients.

Kassis also highlights that following a high-fiber diet can support feeling full for longer after meals, which can help reduce cravings and facilitate weight loss.

50 Grams of Healthy Fat

To complete the 90-30-50 diet, Kassis suggests consuming at least 50 grams of healthy fats daily. This adds flavor and texture to meals, usually missing in weight loss diets, and activates the body’s fat-burning mechanism.

The recommended sources of healthy fats are avocados, nuts/seeds, nut butter, and eggs. Kassis asserts that incorporating these fat sources into your meals will make them more enjoyable and nutritious.

Fact-Checking the 90-30-50 Diet

The 90-30-50 diet appears simple and flexible, but do its health claims hold up to scientific scrutiny? In this section, I’ll investigate the integrity of this nutrition method.

Is 90 grams of protein enough?

It is recommended by Mayo Clinic’s health guidelines that adults who regularly lift weights, run, or cycle should consume at least 1.2 grams of protein per kilogram of body weight to prevent lean muscle breakdown. For a person weighing 175 pounds, this translates to a minimum of 95 grams of protein daily.

However, more detailed studies suggest that individuals following a calorie-deficit diet may require more protein to maintain lean muscle. The results of a meta-analysis indicated that a minimum protein intake of 1.6 to 2.3 g/kg is more beneficial in these situations¹.

In other words, for an active person weighing 175 pounds trying to lose weight or gain muscle, the minimum daily protein intake is 127 to 183 grams. It is important to note that the protein intake could be higher or lower for your body weight.

Therefore, aiming for a minimum of 90 grams of protein per day is a decent starting point, especially if you currently consume less than that. However, you may need significantly more than that, depending on your body, activity level, and fitness goals.

Does Fiber Help With Hunger and Weight Loss?

Consuming at least 30 grams of fiber daily is recommended as part of the 90-30-50 diet plan to reduce hunger and promote healthy weight loss. But is this claim backed by current research?

A systematic review of epidemiologic studies conducted in 2013 showed that consuming higher dietary fiber is associated with lower body weight². Interestingly, though, 61% of studies demonstrated that fiber did not enhance fullness, and 78% did not reduce food intake.

Therefore, while it is a generally healthy suggestion to consume 30 grams of fiber daily, it should not be considered a major contributor to appetite regulation or weight loss in most people.

Indeed, foods high in fiber are generally high in other healthy nutrients like vitamins and minerals. So, some high-fiber foods to consider adding to your meal plan are broccoli, avocado, whole oats, and beans.

Are Healthy Fats Food for Weight Loss?

The last component of the 90-30-50 nutrition plan is targeting at least 50 grams daily of healthy fats to fuel fat loss while adding rich flavors to your diet. But fats are always controversial, so what does the research say?

A 2018 study investigated the association between dietary intake of specific types of fat and obesity and body weight. Their findings showed that replacing saturated fat with mono- or polyunsaturated fats resulted in more average weight loss³.

Nevertheless, it is important to note that over a nearly 5-year period, the average weight loss was only -0.38 kg (-0.84 lb). Therefore, it is unlikely that this dietary change alone will lead to significant weight loss in the short term.

From a general health standpoint, it’s still an excellent idea to reduce saturated fat intake and replace them with healthier fats. Some healthy fat options include lean meat, fish, olive oil, and nuts.

90-30-50 Example

Next, I will walk you through an example showing the average macronutrient and calorie intake on the 90-30-50 diet.

In this situation, a person aims for the minimum targets outlined in the diet plan. It’s important to realize that for each gram of fiber, you will likely have to eat about four grams of total carbs based on typical high-fiber foods.

Also, we know that each gram of protein and carbs has four calories, while fat has nine calories per gram. That means the minimum targets would result in a daily meal plan that looks something like this:

Example

90 g Protein
120 g Carbs (30 g Fiber)
50 g Fat
1,290 Calories

This example results in a macronutrient ratio of 28% protein, 37% carbs, and 35% fat.

For the average woman who burns 2,000, that’s an over 700 calorie deficit (36%) daily and would likely result in rapid weight loss initially. However, studies show that aggressive calorie deficits of around 40% can result in a loss of lean muscle and a metabolic crash.

Of course, diet creator Courtney Kassis only prescribes these as minimum targets, and you can go higher. Regardless, that leaves it up to you to figure out how much above those targets you should go to optimize your personal results.

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Final Thoughts

Overall, the three pillars of the 90-30-50 diet are based on the sound nutritional advice of eating more protein, fiber, and healthy fats. I believe this simple method can result in fundamental dietary changes that lead to real weight loss in some people.

However, this is definitely not a silver bullet or one-size-fits-all solution. Many people simply won’t fit well within the diet framework and, therefore, won’t get the results claimed.

Additionally, the 90-30-50 diet only recommends minimum targets, so you could easily overshoot your calorie intake and not lose any weight on this nutrition plan.

More Weight Loss Information

The 90-30-50 diet is a unique and easy-to-remember approach to weight loss nutrition. But it’s oversimplified guidelines may not be enough to help you reach your fitness goals.

So here are some additional weight loss articles to help you find a solution that works for you.

How To Get Shredded: 11 Secrets Pros Use To Get Crazy Lean

Free Weight Loss Macro Calculator

Start to Finish Guide on How to Meal Prep for Beginners

How to Use Reverse Dieting to Break the Yo-Yo Diet Cycle

Weight Loss Calculator: Find Calories & See How Much You’ll Lose

40-30-30 Diet Results, Pros/Cons, and Macro Calculator

Nutritionist Tries Fasting-Mimicking Diet for 5 Days

Fasting Mimicking Diet

Alternatively, if you’re ready to switch gears, I have many informative articles on a wide range of weight loss and muscle-building topics. Feel free to browse below.