Recently I was reading a UK fitness magazine that included an article about a diet I had not heard of before: the 90-30-50 plan. Apparently, this diet has been viral on TikTok, but since I don’t use this platform, it ended up reaching out to me through a different way… that’s the power of social media, folks!
Anyway, the article caught my attention, and since the diet is trendy now, I wanted to learn more about it and provide my point of view. Basically, to peer-review it.
What is the 90-30-50 diet?
This eating pattern emphasizes the consumption of a minimum of 90 grams of protein, 30 grams of fiber, and 50 grams of healthy fats daily. It was created by Courtney Kassis, an Integrative Registered Dietitian, to support weight loss, improve metabolic health, and manage chronic conditions, including inflammation. An Integrative Dietitian is similar to a Holistic Nutritionist in the sense that both focus on optimizing wellness and health through food and lifestyle.
If you’d like to learn more about the diet from Courtney herself, she recorded a 1 hour masterclass that you can replay from her Instagram page. That was my main source of information for this article.
Now let’s dive in.
The diet approach
The idea of focusing on protein, fiber and healthy fats is a positive to me, since these nutrients are health promoting for most people. I also like that the plan does not focus (directly) on restrictions.
However, I am not fan of the fixed quantities as I will articulate later. Main point being, we are all unique.
90 grams of protein
The plan requires to consume at least 90 grams of protein daily, for everyone. The rationale is to prevent muscles loss, keep blood sugar stable, and balance hormones, including leptin and ghrelin which regulate the hunger cues. It is recommended to consume 30-50 grams in breakfast and dinner, preferably from animal products. Plant-based protein can be used as a backup source.
My point of view: protein
Spreading protein consumption throughout the day is indeed recommended, as our bodies cannot store it.
However, I do not agree with the fixed protein amount recommendation.
The standard Recommended Dietary Allowance (RDA) for protein for healthy adults with normal levels of activity are 0.8 grams per kg of weight. For example, a 60 kg person should aim for 0.8x 60 = 48 grams.
This ratio changes for specific populations, like active or older people. Furthermore, for active people, the recommendations are different depending on the type of sport, basically if it is focused on strength or resistance (cardio). In general, a ration of 1.2-1.5x per kg of weight can work for non-professional levels of activies. That 60 kg person should aim for 1.2x to 1.5x 60 = 72 to 90 grams of protein per day.
The statement that protein helps prevent muscle loss is only partially true. What is missing is physical exercise: you need to generate demand for protein to make the most of it, to “fix” it. Strength training is ideal, but other forms of exercise work too. Our bodies will eliminate the excess of protein that is not needed, through sweat and urine mainly. Thus, too much protein can overload our kidneys, and some studies even show that it can be detrimental to our bones. Too much unnecessary protein is not healthy.
Getting protein from animal sources is efficient, but not the best way. Many animal products can be pro-inflammatory, specially if they are processed. If one of the goals of the diet is to reduce inflammation, animal products might not be ideal. Furthermore, animal products have no fiber, a fiber is the second tenet of the plan. Therefore, getting protein from plants can be a better way to get your 90 grams, reduce inflammation and ge the 30 grams of fiber. Beans, tofu, tempeh, seeds, nuts, grains, all have protein. Seitan is extremely high in protein, but it is high in gluten too and can be considered pro-inflammatory. So it’s something to be included occasionally only.
Each gram of protein provides 4 kcal, therefore this plan is asking us to ingest at least 4 x 90 grams = 360 kcal of protein.
Conclusion: protein
Thumbs down.
- The 90 g recommendation is too generic and certainly too high for some groups.
- Instead of a fixed number, opt for a range based on the official recommendations. Standard ratio for healthy adults is 0.8x per kg or weight. I am an active person and do both strength and cardio exercise, and personally I try to stay between 1.2x-1.5x per kg.
- Plant-based protein should be the priority to lower inflammation and increase fiber intake (and for environmental reasons, but that’s another topic), Animal protein can be the backup.
- Physical exercise is needed to make the most of the protein intake, and not waste it, overloading our kidneys.
- Spread protein consumption throughout the day.
30 grams of fiber
The diet recommends consuming at least 30 grams of fiber daily, for gut health, blood sugar control, satiety and slower digestion, food waste cleaning, and “detoxification” (notice the buzzword).
My point of view: fiber
I fully agree on the importance of fiber for optimal health; not only for the obvious (gut health), but also for cardiovascular or even mental health, as a result of the bio products generated during its transit through our intestine.
Current recommendations are 21-25 grams for women and 30-38 grams for men, so I think 30 grams is a good generic target goal, on the high end.
But still, I am missing something: hydration.
Fiber alone can be problematic if not taken with enough hydration. Things need to flow down, if you know what I mean. We don’t want too much of debris to get stuck. That’s why, in my opinion, the fiber recommendation should be provided with a hydration recommendation.
There’s no official recommendation for water intake but generally, the 8×8 rule, which means 8 oz of water, 8 times a day, suffices for most people. This should be increased in warm weather, and if perspiration is heavy, like after intense exercise or taking a sauna.
If you are not used to eating this much fiber, start slowly to avoid discomfort, and increase amount over time. As always, prioritize whole foods instead of fiber supplements. I usually double and triple this minimum recommendation by eating plenty of fruits, veggies, whole grains, nuts and seeds. If you focus on plant-based sources of protein like beans or tofu, and you’ll get more bang for your bite: protein and fiber.
There are multiple types of fiber (basically soluble and non-soluble), and some of them provide some caloric value. But for simplification reasons, we will assume that fiber does not contribute to our caloric intake noticeably.
Conclusion: fiber
Thumbs up, with some conditions:
- drink enough fluids, preferably water,
- start and progress slowly,
- prioritize whole foods, not supplements
50 grams of healthy fats
The plan recommends the consumption of at least 50 grams of healthy fat per day. The reason is that fat is needed for hormone balance and blood sugar regulation. It also improves flavor and texture of food. Fat is digested slowly, and help us feel satiated for longer. Kassis even states in the masterclass that “fat does not make you fat, it burns fat”. She also mentions that she aims for about 1500 kcal per day, and makes occasional references to energy in the class.
My point of view: healthy fats
Yes, we do need fats for health, especially Omega 3 and 6 fatty acids.
But – they can be a double edge sword, because:
- With 9 kcal per gram, fats are are extremely high in energy (kcal). And Kassis seems to take calories into consideration. So, fat can actually make you fat, and if weight management is your goal, it makes sense to consume fats mindfully, not freely.
- Some forms of fats (oils in particular) have low nutrition density, that is, they provide many kilocalories for the amount of nutrients provided. They do not provide either protein or fiber. Thus, they are not a big nutritional bang for your bite. But still a big calorie bang.
- Some fats are detrimental to our health (saturated and trans fats). Kassis recommends healthy fats, so she has this covered.
- Fats might make you burn fat if you enter ketosis, like you would do on a strict keto diet. But Kassis does not limit carbohydrates, therefore this might never happen on the 90-30-50 plan. So what she’s stating about fat helping burn fat is not inaccurate, but would rarely apply to her plan.
The best way to consume fats is from healthy sources and in their natural form. This means most plant sources and whole foods: nuts (like walnuts, almonds, pistachios), seeds (like sunflower, chia, flax, hemp) and fruits (avocados, olives). Tropical oils and fruits like coconut and palm are high in saturated fat and therefore do not fall under the category of healthy fats. There is not conclusive evidence about the health benefits of medium-chain fatty acids (MCFAs), abundant in coconut, but there’s plenty of evidence that coconut oil rises blood cholesterol levels. Thus, we want to avoid coconut products, like coconut oil or coconut milk.
The 50 grams of diet result in 9 kcal x 50 grams = 450 kcal from fats per day.
Current recommendation for fat consumption is 20-35% of daily calorie intake. Therefore, if you need to consume at least 450 kcal of fat, your diet should be between 2250 and 1300 kcal.
Conclusion: healthy fats
Thumbs up and down.
- Focusing on healthy fats is the right thing to do.
- However, they are very high in calories and should be used in moderation, especially if weight loss is your goal.
- It’s preferred to consume fats in their whole form: nuts, seeds, fruits.
- Oils should be used in moderation and as a condiment, like in dressings or for drizzling; not as the main cooking vehicle: avoid frying, sauteing is fine.
- Fat won’t make you burn fat unless you follow an extremely low carb, high fat, moderate protein diet (keto diet). But the 90-30-50 diet does not necessarily follow the keto schema, although it could probably be tweaked to approach keto by:
- Eating protein along with fat, to reduce the insulin release.
- Eating small to moderate amounts of low Glycemic Index (GI) carbohydrates.
- Taking a fiber supplement.
What about added sugars?
Added sugars are not only the sugars added to the processed foods, but they are also found naturally in fruit juice, honey, agave, maple syrup, and most table sugars. Nowadays, we know that these sugars are a prevalent cause of chronic disease and metabolic alterations: pre-diabetes and diabetes, high triglycerides, obesity, chronic inflammation and more.
The current recommendation is to limit added sugars to 10% of daily calories, ideally to 5% . For example, a 2000 kcal diet should not have more than 25-50 grams of added sugar (5-10%).
The 90-30-50 diet does not mention added sugars, nor imposes any limit. Even if the diet approach is to focus on nutrients that promote health, I think that for the best outcomes, one should be mindful of added sugar consumption.
What about sodium?
Like added sugars, excessive sodium consumption can be negative for our health. It can cause high blood pressure, edema and other complications. Our main source of sodium intake is not the table salt, but the processed foods we eat. Even an apparently innocent jar of marinara sauce packs tons of sodium per serving size.
Current recommendation is to limit sodium to 2300 mg daily, or 1500 mg for more susceptible population groups.
The exception are situations that cause heavy sweating, like exercising for a long time in the heat, or regular sweat therapy (sauna). In this case, replacing the sodium lost through sweat is required and high sodium intake may be appropriate for health.
The 90-30-50 plan does not mention sodium. Again for the best outcomes, one should be mindful of sodium consumption, especially if dealing with high blood pressure, edema or other metabolic issues, and lifestyles that might require sodium replenishment.
Final thoughts
To me, both the strength and the weakness of the 90-30-50 plan lays on its simplicity and generalization.
Strength, because the 90-30-50 pattern is simple and might be a good starting point for most healthy people from western cultures.
Weakness, because we are all unique in our needs, our lifestyle, our goals, and we come from different cultures and backgrounds.
As human, we like simple answers to complex problems and the 90-30-50 plan does just that, provides an easy recipe to the uniqueness of our nutritional needs. That, with also the promise of weight loss and chronic conditions management. And this might be enough in the 80% of the scenarios, or if your diet is really off right now.
But if your goal is optimal health and wellness, you need to take care of the additional 20%. You are going to need a more customized approach, that takes into account your specific lifestyle, how much you exercise, your taste, your background, your culture, how much time you have to cook, your age and gender, your individual goals and much more.
This doesn’t mean you need to be perfect 100% of the time. Knowledge is empowerment that allows you to make informed decisions. If, for example, you are training for a marathon, you might want to stick to the 100% as much as possible. Instead, you might want to relax to 80% (or less!) during a vacation trip.
The (1.2-1.5) (30+8×8) (20-35) (5-10) (1500-2300) diet
Perhaps, I would reformulate the diet as (1.2-1.5) (30+8×8) (20-35) (5-10) (1500-2300).
Which means daily intakes of:
- Protein: (1.2-1.5) grams per kg body weight
- Fiber: 30 grams of plus 8×8 oz of water
- Healthy fats: (20-35) % of daily calories
- Added sugars: (5-10) % of daily calories. 5% is best.
- Sodium: (1500-2300) mg. 1500 is best, except for some lifestyles.
But unfortunately this diet name would not be so catchy 🙂
Your call to action
If you are currently following the 90-30-50 diet, I invite you to make it even better by watching your water, added sugars, and sodium intake as I have outlined in this article.
If you are not following the diet, but are interested in improving your nutrition, losing weight or managing chronic conditions, I invite you to talk to a nutrition professional for advice, to get custom recommendations. If they clear you for the 90-30-50 diet, excellent, go ahead. You might also want to watch your water, added sugar and sodium intake, as directed by the nutrition professional.
In any case, any step we give towards a better nutrition is always a step in the right direction. Like Hippocrates said:
“Let food be thy medicine and medicine be thy food.”
As always, I read you in the comments.
Be well,
Isabel
thrivebytheslice.com 