The Ray Peat Diet, also known as the Peat Diet, is a nutritional approach based on the work of American biologist Ray Peat. This diet emphasizes the consumption of whole, nutrient-dense foods and restricts the intake of processed and refined foods, while promoting a balance of macronutrients and micronutrients.
The Peat Diet is not a fad diet or a short-term weight loss program, but rather a sustainable way of eating that prioritizes the consumption of whole foods. This approach focuses on consuming foods that are rich in vitamins, minerals, and other essential nutrients, such as fruits, vegetables, lean proteins, and healthy fats.
One of the key principles of the Peat Diet is to limit the intake of polyunsaturated fatty acids (PUFAs), which are found in many vegetable oils, nuts, and seeds. PUFAs are known to cause inflammation in the body, and can contribute to a range of health issues, including heart disease, diabetes, and cancer. Instead, the Peat Diet recommends consuming saturated and monounsaturated fats, such as coconut oil, butter, olive oil, and animal fats.
The Peat Diet also promotes the consumption of protein-rich foods, such as grass-fed beef, wild-caught fish, and pastured eggs. Protein is essential for building and repairing tissues in the body, and can also help to regulate blood sugar levels and promote satiety.
In addition to whole foods, the Peat Diet also encourages the consumption of nutrient-dense beverages, such as fresh fruit juices and bone broth. These beverages can provide important vitamins, minerals, and other nutrients that may be lacking in the diet.
The Peat Diet also emphasizes the importance of avoiding processed and refined foods, which are often high in sugar, salt, and unhealthy fats. Instead, the diet recommends consuming whole, unprocessed foods that are rich in fiber and other important nutrients.
Overall, the Ray Peat Diet is a nutritional approach that prioritizes the consumption of whole, nutrient-dense foods, while limiting the intake of processed and refined foods. This approach can help to improve overall health and wellness, while also supporting sustainable weight loss and healthy weight maintenance. However, as with any dietary approach, it is important to speak with a healthcare professional before making any significant changes to your diet.
What Is the Ray Peat Diet?
Explore the ins and outs of the Ray Peat Diet in a U.S. News in-depth review.
This article is based on reporting that features expert sources.
For anyone who’s ever had a chronic, difficult-to-diagnose health condition, the search for answers can lead to years of frustration. Where medical science sometimes fails to offer a definitive answer, anecdotal evidence and experimentation can occasionally lead to a sustainable solution for some people.
That’s been true for Benedicte Lerche, a biochemist, nutritional counselor and thyroid specialist who struggled with a low-thyroid disorder in her 20s before finally finding the Ray Peat diet. She now offers counseling and support featuring the Ray Peat diet via her service, BiochemNordic, based in Copenhagen, Denmark.
Lerche came across the Ray Peat diet concept when she was working as an au pair in Paris. She was living in a “very moldy, dark apartment,”where she says she was always sick. She assigned all of her various, nonspecific symptoms – headaches, digestive issues, menstrual problems, rashes, blood sugar issues and repeated colds and fevers – to her environment, and when she returned to Denmark, she expected that the symptoms would resolve.
But they didn’t.
Thus, she began seeking help from the medical system, but all of her tests came back as being within normal levels. She says her thyroid function levels were a little on the low side “but not alarmingly low,” so the doctors thought the issue might be something else.
Still experiencing symptoms and frustrated with the lack of answers from the medical establishment, Lerche turned to alternative medicine. A dentist in the alternative community suggested that she had low thyroid function and recommended vitamin supplements to address it. She began researching low thyroid conditions and ways to boost function of this important hormone-secreting gland that resides in the neck. She soon came across information about Ray Peat’s sometimes counterintuitive approach to food and health. She found a phone number and dialed. “Very luckily, he just grabbed the phone,” she says.
The two stuck up a correspondence where Peat explained his theories for overcoming hypothyroidism. His recommendations helped Lerche resolve her symptoms. “It was such a relief in a lot of ways,” she says of finally finding the answer to her problems and feeling better.
Inspired by the improvement in her health and overall well-being, Lerche pursued a PhD in biochemistry. Today, she counsels other people struggling with low thyroid conditions to better health via her BiochemNordic platform and a slew of online resources including ebooks, recipes and blog posts.
What Is the Ray Peat Diet?
The thing about the Ray Peat diet is that there isn’t really a set Ray Peat diet. Erin Holley, a registered dietitian at the Ohio State University Wexner Medical Center in Columbus, says that “apparently the Ray Peat diet works to correct hormonal imbalances and improve metabolism through ‘pro-metabolic’ dietary changes.” If that term seems unfamiliar, you’re not alone. “I’m not quite sure what this means because even the people that follow his diet can’t explain it,” Holley says. U.S. News reached out to Peat for an interview but did not hear back.
Peat hasn’t published a book that outlines all the ins and outs of eating to improve thyroid function, and he’s not offering a monthly membership program, cookbooks, recipe lists or simplified lists of foods to eat or avoid in prescribed amounts, like so many other diets out there. Instead, finding the essence of the Ray Peat diet takes a lot of digging and reading into various online networks and forums, some of which include unconventional alternative medicine advice alongside mainstream nutritional and health advice.
Nevertheless, the Ray Peat diet has many staunch followers, such as Lerche, who’ve found freedom and relief in his unconventional ideas. This eating concept draws from the Peat’s research and, to a certain degree, is open to interpretation by the user.
According to information posted on the website raypeat.com, which is attributed to Peat himself, he holds a PhD in biology from the University of Oregon, with specialization in physiology. He has taught at the University of Oregon, Urbana University, Montana State University, National University of Naturopathic Medicine, Universidad Veracruzana, the Universidad Autonoma del Estado de Mexico and Blake Austin College. He has also offered private nutritional counseling.
Peat’s biography notes that he started his work with progesterone and related hormones in 1968. “In papers in Physiological Chemistry and Physics (1971 and 1972) and in my dissertation (University of Oregon, 1972), I outlined my ideas regarding progesterone, and the hormones closely related to it, as protectors of the body’s structure and energy against the harmful effects of estrogen, radiation, stress and lack of oxygen,” he writes. “The key idea was that energy and structure are interdependent, at every level.”
Holley says that while there’s a lot of information online about the Ray Peat diet, most of it comes from people other than Peat himself, and they aren’t always reliable sources. “The info I found online came from non-credible people, such as wellness coaches, functional nutrition therapy practice.
What to Eat on the Ray Peat Diet
If there can be a codification of the Ray Peat method, it would seem to include eating:
- Healthy fats, such as coconut oil and butter.
- Dairy products, with a strong emphasis on milk, cheese and ice cream.
- Lots of fresh fruit and fruit juices.
- Root vegetables.
- Protein from muscle and organ meats.
- Collagen, a protein the body uses to keep bones, tendons and muscles strong and support skin health.
Lerche says there’s plenty of fruit and meat in the Ray Peat diet and that while most dietitians and doctors these days warn people against the use of sugar, “Ray Peat is not afraid of sugar. That’s because the liver needs sugar to activate the thyroid hormones.” She says by consuming simple sugars, you can support your liver in its efforts to stabilize your hormones.
For this reason, she says that “completely normal, white sugar is actually not dangerous. Sugar is basically from nature,” as it’s present in fruits, honey, dairy products and so on. “Natural sugar promotes cellular energy,” she adds, since it’s the fuel that cells run on; the body takes glucose from the foods we eat to fuel cellular function.
Lerche cautions that a more welcoming attitude toward white sugar doesn’t give you a free license to “go out right now and drink gallons of Coca-Cola every day. Because the problem with doing that is that it’s only sugar.” With sweet things like fruit and honey instead, you’re getting some other health-supporting vitamins and minerals.
As such, orange juice is “very big in the Ray Peat diet. There’s always juice with everything,” Lerche says, though she recommends rinsing your mouth out with plain water after drinking orange juice as the sugars can lead to tooth decay.
For her part, Holley says that as a dietitian, she finds this emphasis on simple sugars such as juice and white table sugar “fascinating. These are certainly easy-to-digest sugars and do not cause harm in moderation. But some followers report that Peat has been known to drink a quart of orange juice at a time. I would not recommend that,” as a quart of orange juice can contain more than 450 calories and 83 grams of sugar.
How Much You Can Eat on the Ray Peat Diet
Portion size doesn’t really enter the conversation for many proponents of the Ray Peat diet, and this approach doesn’t typically have weight loss as its primary aim. Fundamentally, followers of this diet have different goals than those trying to lose weight; most of them are seeking relief from underdiagnosed or difficult-to-pinpoint thyroid or other hormone problems.
Focus on Red Light
Light therapy is also a component of the Ray Peat method, with a focus on red light as a possible anti-stress mechanism that can support longevity and reduce the cellular deterioration that comes with aging. Red light, which is a component of sunlight, can penetrate tissues easily and support healing, Peat has suggested. Living in a dark environment without much sunlight can be detrimental to health, he argues. Lerche adds that if you live in a climate where you can’t get enough sunlight daily, it may be worth investing in a light therapy machine to boost your levels.
Eat the Right Kind of Fat
A key tenant of the Ray Peat diet centers around the type of fat you should be consuming if you have a hypothyroid condition.
Polyunsaturated fats, also called polyunsaturated fatty acids or PUFAs, are a type of fat that’s liquid at room temperature. In conventional nutritional circles, PUFAs are considered heart healthy because they contain omega-3 fatty acids, which have been shown to reduce the risk of heart attack and heart disease. Vegetable oils, nuts, seeds and fatty fish like salmon and mackerel are all good sources of polyunsaturated fats.
However, proponents of the Ray Peat diet say that PUFAs are detrimental to health because they inhibit thyroid function. PUFAs also contain omega-6 fatty acids, which can have negative effects on heart health when consumed in excess. One of the omega-6 fatty acids, called linolenic acid, is converted in the body to arachidonic acid, which can promote inflammation and vascular problems, such as blood clots and narrowing of blood vessels.
In addition, Ray Peat diet followers, citing PUFAs’ low melting point, say that it is an unstable type of fat; the claims are that PUFAs can easily oxidize, which causes the oil to go rancid and become toxic. Oxidation creates free radicals, which can cause damage to cells throughout the body.
Examples of PUFAs include:
- Vegetable oil.
- Canola oil.
- Corn oil.
- Soybean oil.
- Walnut oil.
- Cottonseed oil.
- Peanut oil.
- Flaxseed oil.
PUFAs also show up in many packaged and prepared foods including:
- Energy or granola bars.
- Potato chips.
- Commercially raised poultry, beef and eggs. Animals that consume a diet that’s high in corn and soy will have high levels of PUFAs in their products.
- Fast foods and fried foods.
- Fish oil and seafood.
Lerche says that while PUFAs do appear to lower the levels of cholesterol in the blood, which is why conventional nutritional science says they’re heart-healthy, they do so by “actually poisoning the liver in some way so that the cholesterol doesn’t show up in the blood.”
There is some limited evidence that PUFAs could increase the liver’s burden, though the issue seems to come down to the ratio of helpful omega-3 fatty acids to potentially damaging omega-6 fatty acids, and the scientific research has so far been mainly conducted in animals.
Instead of using PUFA-heavy cooking oils, the Ray Peat approach advocates for using more stable, saturated fats for cooking such as:
- Coconut oil.
- Butter or ghee (clarified butter).
Opting for pasture-raised or grass-fed animal products is another way to remove PUFAs from your diet.
However, because these sources of fats are saturated fats, which are solid at room temperature, conventional dietary advice says to avoid them. Saturated fats can elevate the level of LDL cholesterol – that’s the “bad” kind in the blood, and it may increase the risk of heart disease and stroke.
Other foods to avoid include:
- Nuts, seeds and nut and seed butters because of their PUFA contents.
- Low-quality, highly processed foods, such as packaged or fast foods, also because of PUFAs.
- Beans, lentils and other legumes because they are high in fiber, which Lerche says the body isn’t designed to digest readily and can tax the system, leading to reduced thyroid function.
Is There Science to Back Up the Ray Peat Diet?
As a scientist himself, Peat has performed studies of hormones and how diet can influence them. There is some evidence hinting at these ideas, but generally speaking, the concept lies outside the bounds of conventional nutritional advice. It’s also unclear whether the anecdotal results some believers have found with this eating method are actually a result of the diet.
Holley says that while there’s little scientific research to support some of the claims made by devotees of the Ray Peat method, “I do not believe these foods to be harmful either.”
As with many other off-the-beaten-track diets, there’s a mix of good advice and questionable nutritional ideas that have been ascribed to Peat. One that Holley points to is the Ray Peat carrot salad, which recently became a viral sensation on TikTok. Followers claim that the salad balances hormones, such as estrogen. Holley, however, says, “Please do not fall for this. Yes, it’s good to eat carrots, but carrots do not balance hormones.”
Should I Try the Ray Peat Diet?
Bottom line, this approach isn’t necessarily bad or wrong, but if you have thyroid issues, it’s important to seek advice from a medical provider. While it’s true that some thyroid disorders can be difficult to diagnose and that diet can be a powerful tool to support individuals with health conditions, there are treatments available for hypothyroid conditions that don’t require completely revamping your diet or vastly upping your intake of orange juice.
That said, Holley adds, “I really don’t think any of these foods are bad or wrong to include in your diet. But I would not recommend limiting oneself to only the foods that are part of this diet.”
In the end, she says that “the best thing for us is truly getting as much variety as possible. This is how we get more vitamins, minerals, phytochemicals, antioxidants, fiber (and a) variety of prebiotics and probiotics.”
The U.S. News Health team delivers accurate information about health, nutrition and fitness, as well as in-depth medical condition guides. All of our stories rely on multiple, independent sources and experts in the field, such as medical doctors and licensed nutritionists. To learn more about how we keep our content accurate and trustworthy, read our editorial guidelines.
Erin E. Holley, MS, RD, LD
Holley is a registered dietitian with the Ohio State University Wexner Medical Center in Columbus.
Benedicte Lerche, MSc, PhD
Lerche is a biochemist, nutritional counselor and thyroid specialist offering the Ray Peat diet via her service, BiochemNordic, based in Copenhagen, Denmark.