Is a high protein diet right for PCOS?

Hello everyone,

How is 2025 going?

Today I want to discuss high-protein diets. They have been “the thing” in diet world for a bit now. You can tell what’s cool in the diet industry by how many products you can see on the aisle on the supermarket screaming at you: high protein, high fibre, low fat etc.

The question is: is a high protein diet superior for our condition? and if yes, how much protein do we need?

Let’s deep dive into it.

In this newsletter:

1. What is the scientific evidence for high protein diets for PCOS?

2. Does it help with weight-loss?

3. Does it help with insulin resistance?

4. Does it help with lowering testosterone?

5. Is it better for PCOS?

6. How much should protein do I need to eat high protein?

7. 6 high protein meal ideas for breakfast, lunch, snacks and dinner

   

A systemic review published in 2024 “Effects of high-protein diets on the cardiometabolic factors and reproductive hormones of women with PCOS” starts with the sentence: “The optimal dietary regimen for polycystic ovary syndrome (PCOS) has not been identified.” This is important for all us to remember when PCOS influencers start recommending specific diets for our condition. I am a strong believer in finding the right diet that works for you. I also think there is no such thing as the “right universal diet”. Evolutionary speaking humans ate what was available to them at any given time. Not knowing what is healthy for us it’s a modern problem caused by the abundance of food. Science has helped us understand what nutrients we need for optimal health. The way those nutrients are obtained highly depends on your culture, food availability and geography. Back to the high protein topic.

A systematic review is like a comprehensive research project that includes finding, evaluating, and synthesising all relevant studies. It’s a way of looking at all of the studies on a subject and make a judgement on a topic.

This specific systemic review looked at 8 RCT that involved a total of 300 participants. Not a very big pool of people considering you need two control groups.

They compared the following:

1. A high protein diet (30% protein, 40% carbohydrate, and 30% fat)

2. A higher carbohydrate, lower protein (15% protein, 55% carbohydrate, and 30% fat)

Let’s look at Sophia and Ana. They would have been on these two diets at the same time for 4-12 weeks.

It’s important to note that both are on restricted calories. This means that both groups followed a specific caloric restriction, typically 20-25kcal/body weight/day.

This is what happened:

Effect on weight loss

Calorie restriction is more important than the macronutrients when it comes to weight loss. This means the balance of macronutrients (like protein, carbs, and fats) doesn’t seem to impact weight loss much.

However, being on higher protein diet seems to:

• maintain more of the muscle mass during weight loss - this is important for PCOS for two reasons: 1) insulin resistance and 2) bigger muscles means more calories are burned when we are not moving

• keep us fuller for longer so the experience of calorie restriction might be more bearable

• when we eat protein we burn more calories digesting it. We spent 30% of the calories we eat on digesting protein, compared to only 10% carbs and 5% fat.

The results for weight and BMI showed the tendency for high protein diet to lead to more reduction of weight and BMI but it was not statistically significant. However maybe if done for more than 12 weeks it would show different results.

Effect on Insulin resistance

This is where it get interesting. High protein diets were more effective than the normal protein diet in reducing insulin resistance, especially when it was followed for more then 12 weeks. This is why:

• Protein and amino acids stimulate insulin secretion, but they also boost insulin clearance, leading to lower overall insulin levels in the blood.

• The higher protein diets usually means we will consume less carbohydrates which can improve insulin sensitivity, support better pancreatic β-cell function, and enhance the body’s natural insulin clearance.

Testosterone levels

Both Ana and Sophia experienced less testosteorne levels markers. This highlights that, regardless of whether a high-protein diet is used, restricting calorie intake is helpful for improvements in hormonal balance.

A word of caution with high protein diets

While concerns have been raised about potential risks like osteoporosis and kidney damage with HPDs, no serious adverse events were reported in the studies analysed in the systemic review above. These are some concerns:

• Bone Health: High protein diets may increase urinary calcium loss, but they also improve calcium absorption and balance other factors (e.g., insulin-like growth factor-I), so bone health is not negatively affected.

• Kidney Stones (Nephrolithiasis): High protein diets might increase the risk of kidney stones due to higher calcium excretion, but weight loss from the diet may reduce risks associated with metabolic syndrome. Screening for kidney health is recommended before starting eating too much protein.

Overall, they are safe for most individuals, but medical history and kidney function should be evaluated beforehand. If you have a family history of these diseases I would proceed with caution. It’s always a good idea to discuss your diet with a nutritionist if possible.

My other concern with high protein diets is the quality of protein. Unfortunately it requires to eat quite a bit of meat, which we must pay attention to. This topic deserves its whole article so I will stop here.

Should I eat a high protein diet?

Overall it seems like a higher protein diet might be beneficial for us when it comes to insulin resistance. If you are trying to lose weight, upping your protein levels might make the experience better and preserve the muscle mass which is very important for our aging process and overall health.

According to this recent analysis and my nutritionist judgement on this one, I think it’s a good idea to increase our protein levels. For our sanity I wouldn’t measure it gram by gram like some of they gym bros. I would keep a food diary for 4 days and assess what your protein levels are right now and take it form there to add more protein slowing. However I know increasing protein is not easy as protein sources are usually more expensive, harder to find easily on the go and require cooking.

Let’s see what we can eat to achieve a higher protein diet.

Before you look into what you’d need to eat to achieve a high protein diet, let’s calculate how many grams that would be, given we want to be in a calorie deficit.

How much protein do I need to eat in order for it to be a high protein diet?