The Ray Peat Diet: A Unique Pro-Metabolic Approach

Ray Peat’s Bioenergetic Diet has caught on like wildfire in some circles lately, like veganism, paleo, keto, and carnivore.

It’s become the go-to choice for those looking to heal and find a unique approach to their nutritional needs, especially for those who’ve ventured into carnivore territory and found it lacking.

If you’re intrigued by optimizing your metabolism, increasing your energy levels, and achieving lasting fullness, you’re in for a treat. Ray Peat’s dietary philosophy is a refreshing departure from the typical diet trends that focus on avoiding specific foods or macronutrients. Instead, it’s a complex yet fascinating approach centred around “pro-metabolic” eating.

In this article, we’ll take a deep dive into Ray Peat’s unique dietary principles, explore the foods he recommends (and those he advises against), and dissect the pros and cons of his approach.

If you’ve ever wondered about the science behind metabolic optimization, the role of sugar and fats in your diet, or how to strike the right balance between carbohydrates and proteins, this article is your ultimate guide.

So, are you ready to unlock the secrets of the Ray Peat Bioenergetic Diet and find out if it’s the optimal way for you to eat?

Let’s dive in!

Who Is Ray Peat? 

Before we dive in, let’s look at who Ray Peat was.

Raymond ‘Ray’ Peat was born in 1936.

Sadly, Peat passed away on 24 November 2022 at age 86.  

Peat has a PhD in biology, with a specialisation in physiology through the University of Oregon.  Since the 1960s, he taught at many universities and engaged in research, which led to his world-renowned ‘Ray Peat diet’.

Peat’s research focused on the endocrine system and the hormones that drive energy expenditure and weight loss.  Peat began studying progesterone in 1968 and later moved on to other endocrine hormones like thyroid hormone and estrogen. 

What Diet Does Ray Peat Recommend, and Why?

Peat constructed his ‘bioenergetic’ and ‘pro-metabolic’ diet based on his research findings. 

Peat’s dietary approach differs from some of the other WOEs we are used to that usually avoid a particular ‘bad food’ (e.g., carbs, fats, plants, animals etc.) — it’s a bit more complex.

Instead of targeting a food group, macronutrient, or compound, Peat recommends foods he believes to be ‘pro-metabolism’.  When someone’s thyroid and sex hormones are optimised, energy levels increase, and healing and regeneration will ensue.

Subsequently, Peat avoids thyroid-suppressing foods and compounds that can inhibit endocrine function, including a wide array of plant foods and some animal foods.

What Is the Ray Peat Diet, and What Is Pro-Metabolic Eating?

There are many moving parts and theories to a Ray Peat lifestyle.  However, the core of Peat’s approach is to ensure the body feels like it’s in a safe and plentiful environment (i.e., out of starvation) to perform optimally.  This is how it has been coined ‘pro-metabolic’. 

In evolutionary times, our bodies would downregulate their metabolic rate by slowing the thyroid and ceasing reproductive function to save energy if we faced scarcity.  Of course, this was temporary, but it allowed us to survive.  

In many ways, Peat’s dietary approach is the antithesis of many dietary approaches that encourage people to restrict carbohydrates, particularly sugar and restrict their eating window.  So, it’s no wonder many people who get burned out and keto, carnivore, and fasting end up gravitating to Peat’s teachings. 

Providing our bodies with abundant energy from carbs and fats allows the body to come out of ‘energy storage’ mode so the metabolic rate can increase.  The body perceives a time of food abundance, and regular functioning can ensue (at least, in Peat’s theory).

Peat believes that depriving the body of carbs can inhibit the function of the thyroid and other endocrine systems.  Peat believes that a key pillar of eating should be incorporating abundant amounts of all macronutrients, especially carbs.

Unlike other popular diets like carnivore, keto, Paleo, and veganism, Peat’s WOE emphasises lots of sugar (i.e., fruit, fruit juice, honey, raw sugar, and even soda) AND fat.   

While Peat is very pro-carb and pro-fats, he isn’t as big of a proponent of protein, believing some amino acids suppress metabolism; hence, we should avoid them.

In addition to WHAT you eat, Peat believes that eating small meals very frequently ‘stokes your metabolic fire’.  This is also a foundational principle of eating during bodybuilding prep, but it is built around different macronutrients depending on the time of day.

What Types of Foods Are Allowed on Ray Peat’s Diet?

Unfortunately, there is no definitive food list or approved recipes for Ray Peat’s diet, making it difficult to know what is and isn’t ‘Ray Peat-approved’.  As a result, followers are left to design their diet based on Peat’s theories, articles, forum posts and interviews. 

Most infographics floating around the interwebs are based on the guideline posts outlined on the Ray Peak forum. 

We’ve tried to summarise some of the key principles of the Ray Peat diet. 

• Eating more frequently is recommended for metabolic health.  Time-restricted eating and fasting are discouraged. 
• There is no definitive macronutrient or calorie intake; users are recommended to increase their energy intake gradually.  However, Peat explains most people can burn fat on 2,000 calories per day, even if sedentary.  It seems men consume anywhere from 3,500 calories if they are less active to 4-5,000 calories if they are more active, and women consume 2,000 to 3,000 daily calories.
• Protein intake is moderate and should be at least 80 grams per day.  If you are more active, this is preferably 100 grams.  This should mainly come from dairy, gelatine, and approved ‘low-PUFA’ seafood.  Protein from muscle meat, liver, and eggs should be included but enjoyed sparingly compared to his other preferred protein sources.
• Consume your protein sources with fruit or carbs for efficient metabolism.
• A moderate amount of healthy fats is recommended, mainly from saturated fat sources like butter, coconut oil, and macadamia nut oil.
• Raw, unpasteurised dairy products like milk and full-fat cottage cheese are encouraged in abundance. 

• Fresh fruits, dried fruits, and fruit juices from tropical fruits, citrus, cherries, and melons are staples and should be enjoyed abundantly.  Overall, sugar from honey, white sugar, juice, and fruit should make up a large percentage of the diet.  Ray Peat himself eats more than 1,600 calories (400 grams of carbs) per day from sugar and sugary carbs alone (see interview here).
• Starchy carbs like cooked young squashes, white potatoes, sweet potatoes, and carrots can be enjoyed plentifully. 
• Coffee can be enjoyed without restriction.
• It is encouraged with every meal or snack, especially if you consume a large portion of lean meat.  This is recommended to balance the amino acid profile of leaner meats, particularly the methionine:glycine ratio.   
• Supplementing with white sugar, honey, and Mexican Coca-Cola (which, until recently, contained sugar rather than high fructose corn syrup) is recommended to give the body continuous sources of easy energy.

• Seafood is encouraged.  However, it is limited to low-fat fish like cod and sole, shellfish, and molluscs, and it is advisable to avoid consuming too many fatty omega-3-rich fish.
• Liver is also included, but it’s limited to occasional consumption because it is said to depress the thyroid.
• Chicken and eggs are included but limited to only once every ten days or so.  Per Peat, you also need around 10 ounces of orange juice to balance each egg because they’re such powerful ‘insulin activators’.
• Haagen Daz ice cream, or other ‘clean’ ice creams free of gums, vegetable oils, and other additives, is recommended because it is a good source of sugar and dairy.
• Although beans and legumes are avoided, hummus is allowed in small amounts.

• Pork rinds, popcorn popped on the stove, and corn tortilla chips fried in coconut oil are encouraged for a fatty, salty snack.
• Corn flour (Masa harina) is allowed.
• Chocolate without additives is encouraged.
• Morton’s canning and pickling salts and sulphite-free vinegar are included.
• Generous amounts of real honey are recommended to consume alongside protein or as a snack.
• Water should be kept to a minimum as all the liquids someone needs can be acquired from juice, milk, and fruit.

What Foods Aren’t Allowed on Ray Peat’s Diet?

Now that we know of the ‘do’s’ of a Ray Peat lifestyle let’s look at some of the ‘don’t’s and why these foods are prohibited.

• Like many other whole food approaches, polyunsaturated fatty acids (PUFAs) from seed oils are excluded for their inflammatory, liver-clogging properties.  However, so are whole food omega-3s from fatty fish like herring, salmon, anchovies, sardines, and tuna —which are also PUFAs.  Peat believes omega 3 is equivalent to seed oils and he believes ‘there is no such thing as an essential fatty acid’.

• Muscle meats like lean poultry, beef, pork, veal, and organ meats (i.e., liver) are recommended to be minimised because of their iron, tryptophan, cysteine, and methionine contents.  Consuming gelatine alongside lean meat is recommended to ‘offset’ any adversities that can arise from amino acids, and consuming mineral chelates like caffeine is advised to protect against excessive iron levels. 

• Soy of any sort is excluded due to goitrogens and other antinutrients like phytic acid and lectins.
• Fermented foods like yogurt, apple cider vinegar and black pepper are prohibited as Peat considers them carcinogenic and toxic.

• ‘Above-ground’ vegetables (i.e., nightshades minus potatoes, crucifers, greens, etc.) and herbs that are green, leafy, and fibrous (i.e., thyme, oregano, basil) are excluded because they contain ‘toxins that far outweigh the benefits, even if cooked’.
• Industrialised fruits like apples and pears, seed-containing fruits like berries and figs, and grapefruit are not allowed for various reasons.  Bananas are on the ‘no’ list because they are said to promote serotonin, and dates and dried fruit are discluded because they are estrogenic.  Peat warns against both compounds.
• Grains like wheat, barley, rye, oats, white rice, and brown rice aren’t advised because of their phytic acid and lectin contents.
• Absolutely no beans or legumes are included due to their high antinutrient content.
• Maple syrup is also prohibited.

Pros of the Ray Peat Bioenergetics Diet

With dos and don’ts covered, let’s look at what we believe are some of the benefits of Ray Peat’s approach. 

Minimally Processed Foods

Firstly, it’s good to see Ray Peat mainly recommending whole and unprocessed foods. 

While eating plain table sugar, orange juice, or Mexican Coke might be a bit hard to swallow if you are coming from a whole food-based diet, everything else seems to come from natural whole foods. 

Avoidance of Industrial Seed Oils

Although mainstream nutrition still considers some seed oils ‘heart-healthy’, our analysis has also shown that they’re positively correlated with obesity, overeating, and metabolic disorders. 

Spreading the message that these oils are bad news is definitely a win!  Avoiding foods with industrial seed oils as an ingredient will automatically exclude most modern ultra-processed foods. 

There is plenty of debate around the pros and cons of saturated fat vs monounsaturated fat vs polyunsaturated fat.  But the reality is that our intake of industrial seed oils, mainly monounsaturated fat, has exploded over the past century! 

Today, we’re consuming around 700 extra calories of energy from fat per person per day than we did a century ago.  This increase has come mainly from monounsaturated fat and polyunsaturated fat.  These refined oils are super cheap and super profitable ingredients for ultra-processed foods. 

For more details, see Monounsaturated Fat: Is It So “Good” After All?

Animal Based Protein

While Peat isn’t as big of a proponent of meat-based protein, he still recommends consuming protein from animal sources like dairy.  There is no avoidance of ‘animal protein’ as is often prevalent in some low-fat plant-based circles.  Protein from meat, seafood and dairy are complete proteins or protein sources that provide all the amino acids in one place. 

Because protein and the amino acids that compose it are the most critical nutrients for satiety, we must get enough of ALL of them. 

There are also benefits in getting adequate glycine (a conditional amino acids prevalent collagen and connective tissue) to balance methionine (which is prevalent in muscle meat).  It’s ideal to get twice as much glycine compared to methionine. 

For more on what food components promote satiety, check out The Nutritional Cheat Codes for Optimal Satiety and Health.

Balance Between Fat and Carbs

When the body feels like it is in a state of scarcity—whether from an all-out lack of food, too much fasting, a self-inflicted calorie deficit, or hyper-focusing too much on one macronutrient—the body perceives starvation.  Subsequently, it may downregulate the output of organ systems less essential for survival, like reproduction. 

Additionally, the thyroid might minimise energy output to conserve energy.  When combined, this puts the body in a suboptimal energy state.  This is what Peat is trying to counter.

Similar to autumn, when animals have an abundance of fats and carbs to fatten up for winter, unlimited access to sugar and fats communicates to the body that ‘it’s safe’, food is plentiful, and energy is abundant.  In a food environment like this, the body has access to the raw ingredients it needs for optimal energy output—given the right foods are chosen.  However, it could also make you fat and lead to many modern metabolic diseases related to energy toxicity!

If you have followed my blog for a bit, you may have found some of my writings on Bruce Ames’ Triage Theory, which states that the body will only execute functions essential for survival without certain nutrients.  These ideas are similar, although Peat focuses more on energy than micronutrients.  A nutrient-dense approach focuses on plenty of micronutrients with adequate energy from fat and/or carbs. 

Peat’s avoidance of processed industrial seed oils is good.  Plant-based oils have contributed significantly to the increased energy availability, particularly in refined ultra-processed foods.  Unfortunately, thanks to food manufacturers slipping them into our food, we are now consuming an extra 800 calories per person per day in fat.

As the chart below from our satiety analysis shows, reducing fat nearly linearly aligns with a lower calorie intake. 

Finally, Peat’s diet provides a substantial amount of potassium and calcium from all the fruit and milk it contains.  These nutrients are just behind protein in those most critical for satiety.  

As shown in the charts below, we consume significantly fewer calories when our diet contains more of these minerals. 

Cons of the Ray Peat Diet

Building on our work around managing blood glucose, nutrient density, and satiety, we wanted to highlight some data-driven points on some conflicts that we found with Ray Peat’s diet.

Carbs and Fat

Peat recommends a high-carb, moderate-fat, and lower-protein diet.  While this may seem foreign for people from a low-carb or keto background, many people find that a high-carb, low-fat diet can be an improvement from their baseline diet.  

As shown in the chart below, we tend to eat more when our diet contains about 45% non-fibre carbohydrates, with most of the rest of the energy coming from fat.  We tend to eat less when our diet avoids the danger zone of 40-50% carbs. 

So, a high-carb, low-fat diet tends to be hard to overeat.   But unfortunately, most of us tend to gravitate back to the combination of fat and carbs.  While possible, our data from Optimisers shows that very few people maintain a very low-fat diet. 

Interestingly, we see that, somewhat in line with Peat’s teachings, that a very low-carb diet (i.e., less than 10% energy from non-fibre carbohydrates) is not necessarily better for optimising satiety.  It seems that we actually eat more when our energy from non-fibre carbs is below about 10% of calories. 

While the average population carbohydrate intake is 43% of carbs, your body needs some glucose.  In line with Peat’s teachings on glucagon, it may not be ideal to force your body to create all your glucose from protein.   

It’s no wonder that many people who have burnt out on hard-core keto or carnivore find Peat’s teachings a refreshing change. 

The Dangers of the Fat+Carb Combo

Because we are wired to eat based on what season our body thinks it is based on sunlight and food availability, eating a LOT of carbs and fat and a little protein has our bodies thinking we’re stuck in perpetual autumn.  In autumn, we would be trying to fatten up to have energy for the impending winter.

While Peat recommends some protein-rich foods, they’re not foundational, and it is easy to overconsume fat and carbs in relation to protein.  This is especially true when you are consuming dairy (i.e., cow’s milk for its calves), a beverage produced by a mama cow to make her young grow and develop.

Our satiety analysis shows that mixing carbs AND protein OR fat AND protein tend to increase satiety.  However, mixing fat and carbs together—even from whole foods—often leaves us with a hyper-palatable conglomerate that we are prone to overeating. 

So, one of the risks with Peat’s open-ended guidelines is that people will end up combining lots of carbs with enough fat to put them in the hyperpalatable fat+carb zone that tends to lead us to eat the most. 

Blood Glucose and Insulin Management

Thanks to our analysis of the food insulin index, we also know that carbs raise blood glucose over the short term and fats slightly over the long term.  Hence, combining the two often keeps blood sugars and insulin high for longer than if these foods were consumed independently or with protein. 

For more on the food insulin index, check out Making Sense of the Food Insulin Index.

Peat’s approach prioritises constant energy availability, particularly from refined carbohydrates, to avoid stressing the body.  Meanwhile, keto advocates try to minimise glucose and insulin by avoiding carbohydrates.  However, we believe a more optimal approach is to tailor carbohydrate intake to maintain glucose levels in a healthy range.  

If you want to lose weight, them lowering glucose can be a helpful first step to allow your body to tap into your stored body fat.  But trying to drive glucose and insulin to zero while giving dietary fat a free pass may not be optimal for hormonal function or long-term fat loss from the body.   

For more details on finding the balance, see Glucagon vs Insulin: The Accelerator and Brake Pedal for Your Metabolism.

Protein

Aside from focusing on carbs and fat, followers of Peat’s bioenergetics diet are encouraged to minimise their intake of high-protein foods, particularly from animal sources.  This is because amino acids like cysteine, methionine, and tryptophan are said by Peat to be thyroid suppressive.  Additionally, tryptophan is converted to serotonin, which Peat warns against.

We could not find any research to back up these claims, especially in whole animal foods where the amino acid profile is balanced, and we are not taking amino acid isolate supplements. 

Our research has shown that protein is the most critical nutrient for satiety.  Hence, we eat more until we get enough of it.  We tend to eat a lot more when our diet consists of less protein and more energy from carbs and/or fat.  The key here is not to maximise protein, but rather get enough protein while moderating energy from both carbs and fat. 

Aside from providing satiety on its own, high-protein foods tend to provide a complete array of other vitamins and minerals that our analysis showed are critical for satiety, like zinc, iron, thiamine, riboflavin, niacin, cholesterol, and saturated fat, shown towards the bottom of the following nutrient fingerprint chart.

For more on the top vitamins associated with satiety, check out:

• Best Vitamins for Weight Loss and Satiety, and
• The Effect of Minerals on Appetite, Hunger, and Satiety.

Compared to the other macronutrients, protein is the most blood sugar-stabilising macronutrient.  In fact, some people find that blood sugar drops their blood sugar.  However, this is something that Peat warns against, which he finds to be stressful and ‘anti-metabolic’ because low blood sugar triggers the release of glucagon and other stress hormones. 

We talk about that a little more in the article Glucagon vs Insulin: The Accelerator and Brake Pedal for Your Metabolism.

Blood Sugar Stability

One of Peat’s focal points is that blood glucose should always remain stable, which he addresses by feeding with foods like honey, juice, and sugar.  However, there are a few questionable thoughts here that we want to break down.

First and foremost, some glucose variability is necessary for a healthy metabolism; insulin helps energy flow into the body, whereas glucagon promotes the outflow of energy when blood glucose goes low. 

This is why so many people who use CGMs to flat-line their blood glucose find themselves fatter than when they started.  Healthy people have stable blood glucose levels, but the converse of that statement is not valid: you do not get healthy from manipulating your blood sugars into stability!

We can think of insulin as an anti-catabolic hormone that works like the brake pedal to your metabolism and glucagon as the accelerator.  Insulin slows the flow of stored energy from your liver and body fat so you can use up the fuel coming in from your mouth, and glucagon accelerates the release of glycogen and fat stores in the absence of food.

A healthy metabolism balances energy in and energy out.  When you eat, insulin rises to hold your stored energy in storage until you use up all the energy you just consumed.  Then, between meals, insulin drops, and your pancreas produces glucagon to push out stored energy.  

To maintain a healthy energy balance, we need both hormones.  It’s not that insulin is inherently bad (as some people in the keto community believe) or that glucagon is bad (as Peat’s followers often believe).  The key is to find the balance between the two. 

If we have too little food (i.e., starvation or fasting), we end up relying too much on glucagon, which results in us liberating too much stored energy from our liver glycogen, fat tissue, and eventually our muscles, organs, and bones. 

This is a normal part of releasing stored energy, which is critical to weight loss.  But over the long term, remaining in a glucagon-dominant state is a ‘stressor’ that Peat warns against.

In contrast, if we have too much food and are constantly eating, we are hitting the brakes (i.e., insulin) too much, meaning we will be storing more energy than we will be using.  The more energy (i.e., body fat or the excess food you just ate) you have pilling on, the more insulin you require to hold back all your energy reserves in storage.  Essentially, this is how you become fat and insulin resistant.

Aside from the need for some glucose variability, we also need to consider the magnitude at which the foods Peat is recommending can raise our blood sugars. 

Erratic and extreme swings from high and low blood glucose can put someone on a blood sugar rollercoaster.  Extreme highs can cause oxidative damage and systemic stress.  Low blood glucose, below what your body is used to, can trigger a stress response that results in anxiety, fatigue, and cravings to provide the body with nutrient-poor foods that quickly raise someone’s blood sugar. 

In all three instances, hormonal and thyroid imbalances are known to result.

We know from our work on the food insulin index that high-glycemic carbs like sugar, honey, fruit juice, and cola all tend to spike blood glucose high and fast and plummet not long after. 

In contrast, fat tends to raise blood glucose slightly over the long term.  But combining the two, with minimal protein and fibre, increases the area under someone’s blood glucose curve, meaning their sugars stay higher for longer.

If we ‘try and keep blood glucose stable’ by constantly eating high-glycemic, high-fat carbs throughout the day when our energy storage tanks are already full, our blood sugar won’t have a chance to return to baseline.

When your blood glucose remains high, with no glucagon to balance the insulin, you begin storing body fat, and the symptoms of hyperglycaemia and diabetes may appear.

In our Data-Driven Fasting Challenge,  participants use their blood glucose to guide when and what to eat to ensure they don’t swing to extremes.  This keeps people out of the lowest lows that Peat warns against!

Energy Balance

Dr Peat seems to emphasise that people can continue to increase their metabolic rate by slowly increasing the number of calories they consume over time. 

There is some truth to what he recommends — this is often known as reverse dieting.  However, while you can increase your metabolic rate by optimising your thyroid function through diet, there is a limit. 

Thyroid output is catalysed by nutrients like selenium, iodine, B12, copper, iron, folate, vitamin A, vitamin D, and zinc (amongst others).  If we aren’t getting adequate amounts of these nutrients (i.e., iron) or we consume a ton of nutrient-poor foods like sugar and honey in place of more nutritious ones, we won’t be able to increase our thyroid output.

Peat also recommends his followers consume supplemental thyroid hormone and hormones like pregnenolone and progesterone—regardless of whether there is a proven physiological need or deficiency. 

While these recommendations extend a bit beyond the scope of Optimising Nutrition, it’s worth pointing out that you could theoretically take a ton of thyroid hormone to compensate for your excessive energy intake. 

This would literally raise your ‘calories out’ so you could increase your ‘calories in’, but it might also leave you with a ton of side effects from taking unneeded thyroid meds and self-induced hyperthyroidism!

For more on whether or not calories in and calories out matter, check out Is Counting Calories and Caloric Balance a Waste of Time?

Sugar Emphasis

Peat strongly emphasises supplementing glucose as snacks and alongside meals.  While a small dose of glucose can be a helpful tool that someone with diabetes can use to bring their blood sugar back into range, consuming a lot of it consistently can put someone on a blood sugar rollercoaster.

Because of a principle known as oxidative priority, we must burn off dietary carbohydrates—and alcohol, ketones, excess dietary protein, and fatty acids—before we can use up dietary fat or even dip into our fat stores.  

For more on oxidative priority, check out Oxidative Priority: The Key to Unlocking Your Fat Stores.

Hence, consuming a LOT of glucose to ‘keep blood sugar stable’ will keep sugars from returning to baseline.  This means you will not be accessing stored energy, which can contribute to weight gain, high triglycerides, and high cholesterol. 

As we mentioned earlier, some glucose variability is an important part of our healthy hunger signals!   Eating more glucose more frequently will push sugars high and lead to weight gain, whereas fasting too long too often can contribute to muscle mass loss and a taxed metabolism. 

Aside from blood sugar instability, a high emphasis on juice and fruit can tax the liver.  We know that fructose in high amounts can contribute to conditions like Non-Alcoholic Fatty Liver Disease (NAFLD), which can cause damage over time.  Fruit, honey, and fruit juices are some of the highest sources of fructose.

Some fruit is OK, and is an improvement from ultra-processed food, but moderation is key!

Energy Density

Providing your body with an abundance of carbs and fat can add up pretty quickly, and it can be even harder to turn down if satiety is low and you’re eating low protein.  Hence, this WOE can be relatively energy dense if you’re not careful.  Because calories in always equal calories out, it can be easy to gain weight.

Nutrient Density

Aside from energy density, the Ray Peat diet encourages his followers to avoid many nutrient-dense plant foods because of antinutrients and other compounds that have ‘anti-thyroid’ effects. 

Our nutrient density analysis shows that some of the most nutrient-dense foods—or foods with the most significant amount of nutrients per calorie—are green and leafy vegetables.  But on Peat’s diet, we are advised never to eat most vegetables and green leafy things because ‘no way of preparing them could make them edible or safe’.

You can check out our Low Energy Density Foods and Meals article for more.

Furthermore, animal foods like fish that contain the omega-3 fatty acids docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA) are put on the hot seat.  While these fatty acids are consumed by some of the healthiest populations in the world and are beneficial in thousands of studies, Peat seems to equate them to seed oils.  Seafood not only contains omega 3 but many other beneficial nutrients that many people struggle to get enough of. 

Seed oils do contain omega-3 fatty acids but in the alpha-linolenic acid form.  Unfortunately, this form of omega-3s is not bioavailable to humans, as it must be converted into EPA and DHA.  The conversion rate is only about 3-5%, which is why there is no recommended plant source of omega-3s.

Although Peat thinks otherwise, omega-3s are essential for human life; we need them to make cell membranes, create bile acids, regulate inflammation and blood clotting, and produce hormones.  Without them, we can experience cognitive decline, inflammation, blood sugar dysregulation, poor memory, and mood disorders.

Aside from vegetables and fatty fish, Peat does not recommend regular consumption of liver and muscle meat.  He believes that amino acids like tryptophan, methionine, and cysteine, which are plentiful in these foods, inhibit thyroid function.  However, we could not find any research that supported this claim, and these amino acids are essential for human life.  Additionally, foods like milk contain a substantial amount of tryptophan and cysteine, which is confusing.

In addition to its amino acid content, Peat also warns of consuming too much muscle meat because of its high iron content.  Peat believes we consume too much iron, which contributes to oxidative stress and conditions like haemochromatosis.

The truth is that we need iron to live.  The problem with iron usually comes from an array of other factors, like pre-existing liver conditions, a genetic predisposition, a mineral imbalance, and (or) a reliance on heavily-processed foods that are fortified with iron.  Simply eating meat—especially if it’s balanced with other nutrient-dense whole foods from animals AND plants—should not be the sole cause of iron toxicity. 

Many people today are also concerned about low levels of iron, particularly if they are not consuming a lot of animal-based foods.  However, the amount of iron in the food system has been increasing, particularly from fortified foods.  If you’re concerned about too much iron, the best place to start is by reducing foods like processed breakfast cereals that contain supplemental iron.

Fermented foods

Fermented foods have been used daily for millennia and have been critical for human survival.  To date, no studies have proven that these foods are toxic.  In fact, many have been shown to have beneficial properties, like the ability to fight infection and cure diseases like scurvy.

Last, it’s essential to understand that many foods Peat recommends are nutrient poor.  In other words, ‘staple’ foods like honey, sugar, gelatine, and juice contain very few vitamins, minerals, essential fatty acids, and amino acids per calorie. 

While these foods may contain some, they do not include the complete complex of nutrients like whole food do.

Contradiction and Lack of Credible Resources

Peat says he avoids animal-based protein sources like muscle meat, eggs, and liver because they contain too much methionine, cysteine, and tryptophan, which are ‘anti-thyroid’. 

While these foods contain ample amounts of these essential and conditionally essential amino acids, we could not find any credible resources to back up these claims.  Interestingly, foods like milk and dairy contain a substantial amount of these amino acids.

Peat also warns of the harms of ALL PUFAs, including essential fatty acids like EPA and DHA in seafood.  While light is being shed on the disadvantages of seed-oil-based PUFAs, thousands of studies have backed omega-3s from fish oil for decades, and some of the healthiest populations rely on seafood.  To date, we could not find any studies pointing to the harms of omega 3 besides the blood thinning effects they can have if taken in high doses.

For time’s sake, we’ll limit this to one more.  Peat excludes fermented foods like yogurt, kefir, sauerkraut, and other probiotic-rich foods because their lactic acid contents are ‘toxic’ to the human body.  However, we could not find any literature discussing any ill effects of these foods.  In fact, we encountered the opposite and found that many were associated with positive outcomes, and some were even used as successful treatment modalities in various conditions.   

Digestion

To close things up, Peat’s recommendation to eat small meals more frequently is not exactly ideal for human digestion.

Our digestive system relies on something known as the migratory motor complex (MMC) to food through the digestive tract.  This cyclical pattern occurs in the stomach and small intestine in the absence of food (i.e., in between meals).  Here, food empties approximately every three to five hours. 

Food interrupts the MMC.  As a result, food can ‘pile up’ and contribute to conditions related to microbiome imbalances like small intestinal bacterial overgrowth (SIBO) and candida if someone is constantly eating, eating, and eating.  Just like the human hosts, it can be beneficial to have a balance of feasting and fasting to prevent overgrowth. 

Typical Meal Plan Analysis

Now that we know some of the theoretical benefits and shortcomings of Ray Peat’s diet, let’s see how it holds up in terms of nutrient density.

We had a tough time digging up a formal Ray Peat meal plan, so we took it to the Ray Peat Inspired Facebook group to get something to analyse.

A follower commented with his regular food consumption on a Ray Peat lifestyle, which we entered into Cronometer.  We got the following:

In terms of macronutrients, this ends up being 12% protein, 53% net carbs and 34% fat. 

The Cronometer snip below shows the micronutrient content in terms of the Optimal Nutrient Intakes. 

This diet supplies plenty of calcium, potassium, vitamin C and a moderate amount of all B vitamins except niacin.  Per our satiety analysis, we know that potassium and calcium are just behind protein in nutrients critical for satiety. 

But as we can see, the per cent of total calories from protein (protein %) is just 12%.  This leaves our calories from fat and carbs at 35% and 52%, respectively, which aligns with the hyper-palatable fat-and-carb danger zone that is the least satiating.  This is pretty close to the hyperpalatable micronutrient profile of ultra-processed foods like a doughnut or cookie, which provides tons of energy but leads most people to overeat and gain fat. 

Nutrients like niacin, selenium, manganese, omega-3 fatty acids, omega-6 fatty acids, vitamin E, and vitamin K are tough to come by overall.  This is because the predominant sources of these nutrients are plant foods, seafood, and ‘banned’ animal foods like muscle meat.  Hence, avoiding these whole foods can run you into deficiency if you’re not careful.

Does the Peat Diet Provide Enough Protein?

Per our analysis of these two ways to do the Peat diet, we may not be consuming enough protein to support optimal satiety.  As shown in the chart below, Optimisers who consume a higher protein % tend to consume fewer calories.  The 12% protein of the Ray Peat meal plan aligns with the highest overall calorie intake.   

Again, satiety is not really about eating more protein, but rather finding the right balance between protein and energy from fat and carbs.  In our Macros Masterclass, we walk our Optimisers through dialling up their protein and fibre intake while dialling back their fat and carb intake to optimise their satiety and nutrient density. 

Although these two approaches to a Ray Peat lifestyle may not have provided enough protein for optimal satiety, we may be able to if we prioritised more approved seafood, meat, cheese, milk, and other approved dairy.  These higher-protein foods are allowed; it just depends on how you build your plate!

How Could We Optimise the Ray Peat Diet? 

If you’re a firm believer in Ray Peat’s principles for thyroid health but want to optimise your nutrient density, there are a few things you can do to ensure smoother sailing.

First, prioritise approved foods that contain more protein, like dairy products, shellfish, and approved seafood.  Additionally, ensure you get your allotted muscle meat and liver portions each week.  Starting by dialling in your protein intake is the best way to get all the nutrients you need to feel your best, allowing you to eat fewer calories while staying full.

You could also try and swing towards one macronutrient extreme or the other, meaning you would consume EITHER more fat OR more carbs, depending on what you prefer.  It is not fat or carbs that cause weight gain, but the combination of fat and carbs together.

Instead of eating 5, 6, 7, or even eight meals per day, you could try and condense your meals into 3 or 2 using your blood glucose as a guide, as we do in our Data-Driven Fasting Challenges.  Not only is this beneficial for digestion, but it can also help support healthy blood glucose levels and regulate body weight.  If you already have a blood glucose meter, you can get started with our DDF app using your glucose to guide your meal timing.   

Lastly, it could be helpful to try minimising high-sugar isolates like orange juice, Mexican Coke, and honey.  While these foods contain a lot of sugar (i.e., energy), they are not significant sources of nutrients.

To put this into perspective, we included a Cronometer snapshot of the nutrients in 100 grams of honey.

100 grams of sugar:

And four cups (one quart, about one litre) of orange juice:

While orange juice still provides some nutrients, we would still be missing a ton of critical nutrients if it made up 60%, 40%, or even 25% of our calorie intake.

Top 5 Ray Peat Best Foods (Based on Nutrient Density)

While some of the most nutrient-dense foods are prohibited on Peat’s diet, there are others we could prioritise to optimise our nutrient density.  We’ve included our top five most nutrient-dense Ray Peat-approved foods below.

• Liver.  Liver is recognised as a superfood amongst many popular diet and nutrition crowds.  However, it is only allowed sparingly on Peat’s diet.  We recommend ensuring you don’t miss out on your 2-3 allotted servings per week!   The Cronometer snip below shows the nutrients in 150 g of beef liver.  You don’t need a lot of it to get heaps of vitamin A, B12, copper and a range of other nutrients that people following the Ray Peat diet may be missing out on. 

Just one 150-gram serving provides you with a large chunk of your protein goal and a substantial amount of B vitamins (including niacin), vitamin A, folate, copper, and zinc, a few nutrients the meal plans had a difficult time providing.

We know that when we get more protein, zinc, and B vitamins like folate and riboflavin, we are more likely to be able to eat fewer calories and still feel fuller.

• Oysters. 
• Oysters are a nutritional powerhouse if one ever did exist.  While oysters provide a moderate amount of protein, cholesterol, selenium, and omega-3 fatty acids, they also offer heaps of zinc, copper, B12, and iron, which are critical for satiety, thyroid function, and sex hormone synthesis.  Some of these nutrients were harder to come by on the other meal plan examples.  150 grams of canned oysters in olive oil provides heaps of B12, copper and zinc. 

• Mussels.  Like oysters, mussels are another superfood of the sea.  Because they are shellfish, Peat allows them.  Their high B12, omega-3, manganese, selenium, iron, niacin, and protein content make them excellent additions to any Ray Peat-style diet.  150 grams of mussels provides:

• Eggs.  Although Peat recommends eating eggs sparingly, we had to include them for their superior nutrient density.  Eggs provide bioavailable protein, B vitamins, selenium, and iron.
• Cottage cheese.  Cottage cheese is a low-calorie, high-protein source that fits Peat’s approved food criteria.  Aside from being an efficient source of all the essential amino acids, cottage cheese also supplies a good bit of phosphorus, magnesium, calcium, selenium, B vitamins, and a bit of zinc.

Overall, some of the nutrients this diet lacked the most were vitamins B3, E, K, selenium, manganese, omega-3s, and omega-6s.  While eating more of the foods listed above helps provide more dietary B3 (niacin), manganese, selenium, omega-3s, and omega-6s, there aren’t any foods that provide a substantial amount of vitamins E or K1 on a Ray Peat lifestyle.  The best sources of these nutrients are nuts and greens, respectively.

Who Would the Ray Peat Diet be Suitable For?  

If you already have excellent blood glucose control, are trying to gain weight or demand a lot of energy for a high activity level, some of Ray Peat’s principles may be helpful to move you towards your goals.  The ratio of carbs, fat, and protein found within a Ray Peat diet is excellent for promoting appetite so you can eat more which may be helpful if you are already lean and very active. 

Are Sugar and Fructose Good Sources of Energy?

Sugar, like honey, is commonly available in nature and would have been consumed evolutionarily—but only if you were willing to fight a swarm of angry bees for it!  While it is a good fuel source, we wouldn’t have unlimited access to it if we were back in primitive times. 

Fructose boosts blood glucose less dramatically than pure glucose and starch.  However, that does not necessarily mean we should consume more of it.  This sugar makes up a large part of foods like fruit, sugar, and honey and converts more easily to fat in the liver if eaten to excess.  While these foods used to be more readily available in autumn when nature wanted us to get fat, we now have unlimited access to them thanks to globalisation.

Sugar, fructose, and the many foods that provide these ‘nutrients’ are good energy sources for lean and active people who need to refuel.  However, the overconsumption of glucose and fructose whenever you want can contribute to problems over time, and it is akin to the carb-and-fat combo that can contribute to overeating and obesity. 

Is Ray Peat’s Diet Sustainable? 

With easy energy from ultra-processed food available, it’s hard to sustain any extreme diet unless it’s part of a rigid belief system and community. 

To abide by a strict Ray Peat lifestyle, you might have to have a bag of gelatine, honey, and sugar on-hand to supplement your pro-thyroid lifestyle.  Additionally, you might have to keep your activity levels up to avoid some ill effects of the diabolical hyper-palatable, fat-and-carb combination!

Nonetheless, there are some great principles we can take away from Peat’s diet.  It can be sustainable; it just depends on how you build your plate and eating schedule!

Summary

• The Ray Peat diet is designed to provide plenty of energy from fat and carb. 
• It is attractive to many who have become burned out on keto, carnivore or extended fasting approaches.  It may be helpful for someone already lean and very active but is unlikely to be ideal for someone less active or trying to lose weight. 
• Avoiding industrial seed oils is a significant plus of this diet as it will exclude most modern ultra-processed foods.
• Many foods provide fast-acting energy foods like orange juice, honey, sugar or Coke.  While these will tell the body that there is plenty of energy available, they tend to contain fewer proteins, fewer micronutrients, and thus less satiety per calorie. 
• In contrast to keto, the Ray Peat Diet tries to elevate blood glucose.  However, rather than swinging from one extreme to another, it may be better to use your blood glucose to ensure you are getting enough, but not too much, energy. 
• Rather than swinging to extremes, it’s ideal to ensure you get plenty of nutrients with enough, but not too much energy, based on your goals and context. 

More

• Glucagon vs Insulin: The Accelerator and Brake Pedal for Your Metabolism
• Data-Driven Fasting: How to Use your Blood Glucose as a Fuel Gauge
• What Are Macros in Your Diet (and How to Manage Them)?
• How to Make the Most of Your Continuous Glucose Monitor (CGM) Data
• What is Nutrient Density (and Why It Matters)?
• Micros Masterclass