If you’re dealing with thyroid problems or need to optimize your metabolism, you may want to try the Ray Peat Diet, which claims to have positive impacts on thyroid and sex hormones. To decide if this diet can be a healthy choice for you, you need to learn how it works, its benefits, and its side effects. Let’s learn all about this so-called “pro-metabolic” diet.
Highlights
The Ray Peat Diet focuses on fats, carbohydrates, sugar, and moderate protein.
You can consume carbohydrates, animal protein sources, dairy, eggs, liver, root vegetables, and fats.
This diet is claimed to balance hormonal function and insulin levels.
Consuming high levels of carbohydrates and sugar can cause inflammation, heart disease, obesity, type 2 diabetes, cancer, etc.
Who Is Ray Peat?
Raymond ‘Ray’ Peat 1936-2022 was a PhD holder in biology, focusing on physiology, who researched the human body and hormones since 1960.
Studying hormones affecting energy expenditure and weight loss, Peat started researching progesterone in 1968 and later explored other endocrine hormones, such as thyroid and estrogen, which led to the creation of the Ray Peat Diet.
What Is Ray Peat Diet?
Ray Peat Diet is a set of eating rules to reach metabolic health and hormonal balance through pro-metabolic dietary changes.
To provide these changes, you need to consume healthy fats, moderate protein, carbohydrates, coffee, and moderate white sugar, avoid all PUFAs (polyunsaturated fatty acids), and follow the rules below.
"The primary emphasis should be on nutrients that support oxidative energy metabolism."
Rules
Increase the meals throughout the day and eat more frequently.
Avoid intermittent fasting.
There is no rule for macronutrients or calorie intake, but generally, consuming 2000 calories can lead to caloric deficit and weight loss (men consume 3500-4500 calories daily and women consume 2000-3000 calories per day).
Increase your energy intake gradually.
Consume moderate amounts of protein, no less than 80g daily, from dairy products, gelatin, and low-PUFA seafood. More active individuals can consume about 100g of protein daily.
Consume protein sources with fruits (or other carbohydrate sources) to improve metabolism.
Consume moderate levels of saturated fat sources like butter, coconut oil, and macadamia nut oil.
Use plenty of raw, unpasteurized dairy products like milk and full-fat cottage cheese.
Although the food sources to provide the necessary macronutrients for Ray Peat Diet seem controversial, Ray Peat and his followers believe they can lead to improvements in metabolism and weight loss.
To see how far this claim is true, we need to find out how the diet works and how it affects our bodies.
Tip
A study published in the Journal of the Academy of Nutrition and Dietetics examined the effect of meal frequency on energy intake and found that eating more frequent meals throughout the day was associated with a lower total energy intake per meal. This suggests that increasing meal frequency might help in managing overall energy intake (Source: Speechly DP, Buffenstein R. Journal of the Academy of Nutrition and Dietetics. 1999;99(10):1079-1083).
Join 100,000+ subscribers to get monthly emails on the best science-based tools and strategies for optimal health from Rina.
Thank you! You're now subscribed!
Oops! Something went wrong while submitting the form.
We value your time and send just 1 insightful email monthly.
You'll also get Rina's exclusive Daily Blueprint. In it, Rina shares her daily routine. She also shares practical tools and protocols that you can use to heal inflammation and maximize your health.
By submitting your email to subscribe, you agree to The Primal's privacy policy
How Does the Ray Peat Diet Work?
The pro-metabolic dietary changes that are claimed to cause health improvements in the Ray Peat Diet include putting the body in a safe and proper environment for optimal performance.
[cta-meetings]
According to his website, Peat believes avoiding carbohydrates can disrupt thyroid function and other endocrine systems. So, carbohydrates are one of the important macronutrients in this diet.
Also, unlike many popular diets like Carnivore, Keto, Paleo, etc., the Ray Peat Diet allows sugar, whether natural (from fruits, fruit juice, honey) or industrial sources like soda, as they’re claimed to be insulin activators.
The theory behind consuming sugar is that the body uses glucose (sugar) to do cellular functions. Ray Peat himself consumed over 1600 daily calories (400g Carbohydrates) from sugar and sugary carbohydrates.
So, this diet allows plenty of carbohydrates and fat but moderate levels of protein, as it’s claimed some amino acids - building blocks of protein - suppress metabolism.
Additionally, those on a Ray Peat Diet need to consume more frequently, as it’s believed to increase the metabolic rate.
To eat in a pro-metabolic way providing the macronutrients necessary for a Ray Peat Diet, you need to know what foods to eat and avoid on this diet.
A study published in the Journal of the International Society of Sports Nutrition investigated the effects of combining protein and carbohydrate intake on post-exercise muscle protein synthesis. It concluded that consuming protein with carbohydrates enhances the anabolic response, supporting muscle recovery and metabolism (Source: Kerksick CM, et al. Journal of the International Society of Sports Nutrition. 2017;14:38).
Ray Peat Food Pyramid
The following food pyramid shows the main macronutrient sources of the Ray Peat Diet.
As the above food pyramid suggests, you can consume whole-food sources, including:
[cta-meal-plan]
Healthy Fats: Butter, coconut oil, tallow, etc.
Seafood and Low-Fat Fish: Oyster, cod, crab, sole fish, shrimp, etc.
Starchy Carbohydrates and Root Vegetables: Carrots, yams, potatoes, bamboo shoots, etc.
Fruits and Fruit Juice: Oranges, grapes, papaya, sapotas, mangoes, lychees, cherries, melons, etc.
Sugar Sources: Honey, cane sugar, white sugar, Mexican cola
Coffee (especially with meat, to balance the amino acid profile of lean cuts of meat, i.e., the methionine: glycine ratio)
Home-made popcorn and corn tortilla chips fried in coconut oil
Chocolate and Ice Cream
Water: Should be consumed minimally as the main sources of hydration are milk, fruit, and fruit juice.
However, some other common foods are not allowed in the Ray Peat Diet, especially anything containing PUFAs (polyunsaturated fatty acids), like nuts, seeds, beans, mayo, soy, etc.
Soy (of any sort) is avoided for containing goitrogens and other antinutrients like phytic acid and lectins.
Fermented Foods: Yogurt, apple cider vinegar, and black pepper (as they are considered toxic and carcinogenic)
Above-ground Vegetables: Crucifers, greens, herbs, leafy, and fibrous vegetables like thyme, oregano, and basil
Industrial Fruits: Apples and pears, seed-containing fruits like berries and figs, and grapefruit
Bananas and dates
Grains: Wheat, barley, rye, oats, white rice, and brown rice (as they contain phytic acid and lectin)
Maple Syrup
All PUFAs (polyunsaturated fatty acids), including nuts (walnuts), seeds (sunflower seeds), fish (salmon, mackerel), seed oils (corn and flaxseed oils), and fish oil
One of the important macronutrients in the Ray Peat Diet is fat, which can be provided from different sources, but not plant-based ones.
Dietary guidelines often recommend limiting saturated fat intake to less than 10% of total daily calories. For example, if following a 2000-calorie diet, this would mean consuming no more than 22 grams of saturated fat per day. Moderate consumption of specific saturated fats like those from coconut oil is generally considered safe within these guidelines (Source: Dietary Guidelines for Americans 2020-2025. U.S. Department of Agriculture and U.S. Department of Health and Human Services. 2020).
What Kind of Fat You Should Eat on Ray Peat Diet?
On a Ray Peat Diet, especially if you have a hypothyroid condition, you need to avoid PUFAs (polyunsaturated fatty acids).
[cta-gocarnivore-plans]
Although these fats are known to be heart-healthy, they’re not allowed on the Ray Peat Diet, as they’re believed to disrupt thyroid function.
Also, omega-6 fatty acids in PUFAs can negatively impact heart health when consumed in excess. Linolenic acid, an omega-6 fatty acid, can be converted to arachidonic acid in the body and cause inflammation and vascular problems, such as blood clots and narrowing of blood vessels.
The followers of this diet also believe that PUFAs are easily oxidized, which can cause the oil to become rancid and toxic.
PUFAs can be found in:
Nuts
Seeds
Fatty fish, such as salmon and mackerel
Vegetable and Seed Oils (like canola, corn, soybean, walnut, cottonseed, peanut, and flaxseed oils)
Margarine
Energy or granola bars
Potato chips
Fast foods and fried foods
So, based on these foods allowed and excluded, which groups of individuals can go on this controversial diet?
Generally, anybody can try this diet and even the followers of the Ray Peat Diet believe that it can be an effective approach to managing thyroid function. However, it’s wise to consult a healthcare professional before trying this diet.
But other than this claim, is there any health benefit to following the Ray Peat Diet?
Ray Peat studied physiology and focused on hormones and the effects of eating habits on hormonal balance, and some - not all - of the foods mentioned in his food pyramid are safe to consume based on recent research.
However, the most important point to note about the Ray Peat Diet is that not enough research has been done on this particular eating routine to explore its short- and long-term effects.
So, most of the information on the benefits of this diet comes from personal reports and user experiences. So, you must be cautious about generalizing the results.
Also, critics of this diet believe while consuming salad or carrots is good, it cannot necessarily balance hormones, such as estrogen.
Anyhow, Ray Peat claimed this eating routine can positively impact thyroid hormones and insulin secretion. Then again, it’s best to consult a healthcare professional for personalized advice, especially if you have underlying health conditions.
To decide if the Ray Peat Diet is something to try, you need to learn about its potential side effects as well.
Ray Peat Diet Downsides
Ray Peat Diet is a high-carbohydrate diet, meaning that consuming large amounts of carbohydrates will prevent ketosis, making weight loss too difficult.
Ketosis is a fat-burning state, where the body relies on fat sources to provide energy. But consuming diets high in carbohydrates will put glucose as the main fuel source and the body’s fat reserves stay untouched.
[cta-meal-plan]
Also, consuming carbohydrates and sugar on a Ray Peat Diet can cause the following health problems.
Research shows that diets high in sugar can cause inflammation and increase the levels of triglycerides, blood sugar, and blood pressure, all of which are heart disease risk factors [1] [2].
Obesity
A 2020 study exploring the association between sugar and obesity found that added sugar, often from sugar-sweetened beverages, is one of the main causes of obesity and weight gain [3].
Despite the beliefs of the Ray Peat Diet followers about the positive effects of sugar on controlling insulin, different studies demonstrate that drinking sugary beverages can increase the risk of type 2 diabetes [4] [5].
[cta-gocarnivore-plans]
Increased Mortality
Analyzing various bodies of research has indicated that consuming high levels of carbohydrates can increase the risk of total mortality [6].
Also, a 2023 narrative review on the effects of sugar on human health has concluded that consuming excessive added sugar has various negative impacts on human health and well-being [7].
Mood Swings and Tiredness
Numerous research shows that consuming carbohydrates can negatively affect mood categories, including alertness and tiredness, reinforcing a vicious circle.
Additionally, consuming sugar can lead to metabolic syndrome and subsequently metabolic disease [8] [9].
Increased Hunger
Sugar-sweetened drinks allowed on a Ray Peat Diet, including soda and fruit juice, contain high levels of fructose (a kind of sugar), boosting your appetite for food, which is against the goal of this diet for calorie deficit and weight loss [10].
Also, a 2022 study suggested that consuming fructose in excess can cause leptin resistance, disrupting hunger cues, which can lead to overeating [11].
Consuming high-sugar foods and drinks can lead to obesity and inflammation, which are among the main risk factors for cancer [12] [13].
Also, a 9-year study on over 22000 men concluded that consuming sugar can increase the risk of prostate cancer [14].
Fatty Liver
Fructose, the natural sugar in fruits, is digested and broken down in the liver. In the liver, fructose is turned into energy or stored as glycogen. However, the liver can only store large amounts of glycogen before converting excess amounts to fat.
Consuming too much fructose from fruits and fruit juices causes fructose overload in the liver, leading to nonalcoholic fatty liver disease (NAFLD) [15] [16].
Side effects aside, the main difference between the Ray Peat Diet and other diets is its focus.
What Differentiates Ray Peat Diet from Other Diets?
The main difference between the Ray Peat Diet and similar diets is that it doesn’t categorize foods as good or bad. Rather, it includes all macronutrients but at varying levels.
Instead of focusing on a particular food group, Peat focused on pro-metabolism and suggested foods that boost thyroid and sex hormones to optimize their hormonal balance and energy levels.
He also excluded thyroid-suppressing foods that can disrupt endocrine function.
If you’re interested in diet and think it can align with your health and fitness goals you can use the following sample 7-day meal plan to get started, of course, after consulting a healthcare professional.
Here is a sample 7-day meal plan for the Ray Peat Diet. You can modify the foods based on your specific needs and preferences, but ensure to avoid the foods excluded from the diet.
Day 1
Here are the foods you can eat on the first day of the week on the Ray Peat Diet. The table also shows the carbohydrates, fat, protein, sugar, fiber, and calories you can get from this day's meal.
Meal
Food
Carbohydrates (g)
Fat (g)
Protein (g)
Sugar (g)
Fiber (g)
Calories
Breakfast
Greek yogurt with berries and honey
25
5
15
20
5
300
Lunch
Grilled chicken salad with mixed greens
15
10
25
5
6
350
Dinner
Baked salmon with steamed vegetables and quinoa
40
15
30
5
8
450
Day 2
Here are the foods you can eat on the second day of the week on the Ray Peat Diet. The table also shows the carbohydrates, fat, protein, sugar, fiber, and calories you can get from this day's meal.
Meal
Food
Carbohydrates (g)
Fat (g)
Protein (g)
Sugar (g)
Fiber (g)
Calories
Breakfast
Oatmeal with sliced banana and almond butter
40
10
10
15
6
350
Lunch
Turkey and avocado wrap with side salad
30
15
20
5
6
400
Dinner
Beef stir-fry with broccoli and brown rice
45
20
25
5
7
500
Day 3
Here are the foods you can eat on the third day of the week on the Ray Peat Diet. The table also shows the carbohydrates, fat, protein, sugar, fiber, and calories you can get from this day's meal.
Meal
Food
Carbohydrates (g)
Fat (g)
Protein (g)
Sugar (g)
Fiber (g)
Calories
Breakfast
Scrambled eggs with spinach and whole-grain toast
30
15
20
5
6
400
Lunch
Lentil soup with a side of mixed greens salad
35
10
15
5
8
350
Dinner
Grilled shrimp with roasted vegetables and couscous
50
10
30
5
6
450
[cta-gocarnivore-plans]
Day 4
Here are the foods you can eat on the fourth day of the week on the Ray Peat Diet. The table also shows the carbohydrates, fat, protein, sugar, fiber, and calories you can get from this day's meal.
Meal
Food
Carbohydrates (g)
Fat (g)
Protein (g)
Sugar (g)
Fiber (g)
Calories
Breakfast
Cottage cheese with sliced peaches and honey
25
10
20
20
5
300
Lunch
Chicken Caesar salad with homemade dressing
20
15
30
5
6
400
Dinner
Pork chops with roasted vegetables and sweet potatoes
35
15
25
10
7
450
Day 5
Here are the foods you can eat on the fifth day of the week on the Ray Peat Diet. The table also shows the carbohydrates, fat, protein, sugar, fiber, and calories you can get from this day's meal.
Meal
Food
Carbohydrates (g)
Fat (g)
Protein (g)
Sugar (g)
Fiber (g)
Calories
Breakfast
Smoothie with banana, spinach, and protein powder
30
5
20
15
6
350
Lunch
Tuna salad with crackers
25
10
20
5
4
300
Dinner
Baked cod with roasted asparagus and quinoa
40
10
30
5
6
400
Day 6
Here are the foods you can eat on the sixth day of the week on the Ray Peat Diet. The table also shows the carbohydrates, fat, protein, sugar, fiber, and calories you can get from this day's meal.
Meal
Food
Carbohydrates (g)
Fat (g)
Protein (g)
Sugar (g)
Fiber (g)
Calories
Breakfast
Yogurt parfait with granola and fruit
35
10
15
20
5
350
Lunch
Veggie burger with avocado and side salad
30
15
20
5
6
400
Dinner
Baked chicken with roasted Brussels sprouts and mashed potatoes
35
20
30
5
7
450
[cta-meetings]
Day 7
Here are the foods you can eat on the seventh day of the week on the Ray Peat Diet. The table also shows the carbohydrates, fat, protein, sugar, fiber, and calories you can get from this day's meal.
Meal
Food
Carbohydrates (g)
Fat (g)
Protein (g)
Sugar (g)
Fiber (g)
Calories
Breakfast
Pancakes with maple syrup and fruit
45
10
10
25
5
400
Lunch
Caprese salad with balsamic glaze
15
20
15
10
4
350
Dinner
Spaghetti with marinara sauce and side salad
50
10
20
10
7
450
Conclusion
The Ray Peat Diet is claimed to be a pro-metabolism approach to health and fitness designed by a biologist Ray Peat.
Although the followers of this diet believe it can have different health benefits, from weight loss and hormonal balance to insulin control, not enough research has been conducted on the effects of this diet.
If you wish to try this diet, you should consult a healthcare provider first to ensure the foods included will not negatively impact your health and are in line with your goals.
Every week your favorite Carnivore doctors like Dr Chaffee, Dr Baker, Dr Bright join us LIVE to answer your medical questions and our coaches will help you lose weight and heal inflammation fast.