What is the Pro Metabolic Diet & Is it Here to Stay?

In my most recent blog post, “Eating for Energy”, we explored the concept of “metabolism” not as a measure of how easy or difficult it is for us to lose weight, but as defined by how efficiently our cells can convert potential energy from food into usable fuel for our bodies.

This idea shares some cross-over with the principals of something called the “Pro Metabolic Diet”.

Rapidly gaining popularity, the Pro Metabolic Diet is built on the work of author Ray Peat, and is based on the idea that the body needs a certain balance of protein, fats, and carbohydrates to function optimally. Essentially, it is a nutrition approach that balances these macronutrients in a particular way in order to optimize metabolic health (again, “metabolic” in this instance, refers to cellular function).

The science behind Pro Metabolic Eating is based on the fact that our bodies require energy to perform, and that energy is created by the foods we eat. Our cells break down (or “metabolize”) proteins, fats and carbohydrates to produce ATP (adenosine triphosphate), which is then used throughout the body as its primary chemical energy source.

But how sound are the principals of Pro Metabolic Eating? Is it one of the rare diet trends that could actually withstand the test of time?

Let’s explore some of the pros and cons together.

What We Like…

In many ways, Peat’s dietary approach is the antithesis to so many others out there that encourage people to restrict calories, specifically carbohydrates. In evolutionary times, our bodies would down-regulate our metabolic rate by inhibiting thyroid and endocrine functions to conserve energy during times of scarcity.

Peat believed (rightly so) that providing our bodies with abundant energy in the form of food allows chronic dieters to come out of “energy storage” mode and increase their metabolic rate. The body perceives food abundance as a time of safety, thyroid and sex hormones begin to function optimally, energy levels increase, and healing and regeneration can ensue.

Specific foods that Peat believed to be “Pro Metabolic”, and which he encouraged people to eat without restriction included:

• Easy-to-digest carbohydates like fruit, fruit juices and honey
• Collagen-rich animal proteins like skin-on, bone-in meat and bone broth
• Liver (weekly)
• Full-fat dairy including raw/unpasturized milk and cheese
• Whole eggs (including the yolk)
• Starchy root vegetables like potatoes, squash and carrots
• Low-PUFA cooking fats including butter, tallow, lard, and coconut oil

Some dietary practices that Peat also encouraged were eating frequent, smaller meals throughout the day, as he believed this “stokes the metabolic fire” and always consuming protein with an easily-digestible carbohydrate, to optimize metabolic efficiency.

Where the Pro Metabolic Diet Takes it a Bit Too Far…

Like any fad diet on the market, Pro Metabolic Eating has more than few cracks in its foundation, particularly when taken to the extreme.

As much as I align with any dietary approach that champions ancestral ways of eating (grass-fed and pastured, bone-in meats, organ meat, egg yolks, real-food cooking fats, etc.), some proponents the Pro Metabolic Diet build on Ray Peat’s principals to concoct recipes that our ancestors definitely would not have eaten, like homemade gummies made with gelatin powder and fruit juice, high-sugar “adrenal cocktails”, and even ice cream.

Let’s get one thing straight: I do not believe we should fear carbohydrates. The low-carb movement had its 15 minutes of fame, but the research has long-since established that our bodies need glucose from carbohydrates to convert the inactive T4 hormone into the active T3 form that allows our thyroid to function optimally. When carbohydrate intake is restricted, thyroid function declines, causing our metabolic rate to down-regulate, alongside a host of other potential health implications. If you’re interested in reading more in-depth on this topic, check out my previous blog post, “We Need to Talk About Carbs”.

Having said that, carbohydrates that have been stripped of their natural fiber content (also termed “acellular carbohydrates), such as those found in fruit juice and ice cream, have been shown to spike blood sugar too much too quickly, increasing the risk for inflammation, insulin-resistance, energy crashes, brain fog, and weight gain.

Fiber helps to anchor blood sugar. That is to say, it slows the release of glucose from carbohydrate-rich foods into the blood stream, giving our bodies a chance to metabolize it in healthier way – the way our cells have evolved to do. For this reason, I believe we’re much better off including sources of complex or cellular carbohydrates into our diet, like sweet potatoes, quinoa, beans, and whole natural fruits.

And speaking of fiber, the original tenants of the Pro Metabolic Diet would have us avoid a whole range of high-fiber and anti-oxidant-rich foods such as green and cruciferous vegetables, tomatoes, berries, grapefruit, apples and pears, as Peat considered these to be “toxic”, an idea which is not only completely unfounded, but which, if adapted, could cause us to miss out on a wide variety of important nutrients.

Furthermore, the Pro Metabolic Diet advises against consuming Omega-3-rich nuts and seeds, and even fatty fish, because of their “PUFA” content (poly-unsaturated fatty acids). While it’s true that PUFA’s from industrialized seed oils like canola and soybean oil can have inflammatory (even carcinogenic) effects, we now know that the Omega 3 fatty acids found in wild-caught salmon, almonds and walnuts, for example, have anti-inflammatory, health- and longevity-promoting properties that far outweigh any potential threat from their (much smaller) PUFA content.

Lastly (and this is perhaps the biggest misstep of the Pro Metabolic Diet), many people adopt this way of eating as a means to lose weight.

Again, this is where we see the confusion around what “Metabolic Health” actually means come into play. The belief that adopting the Pro Metabolic Diet will help “heal our metabolism” after years of chronic dieting, in turn making it easier to reach a weight-loss goal, is missing the point at best, and the propagation of misinformation and a disordered food culture at worst.  

As we’ve already established, “Metabolic Health” has, at most, only marginal and indirect implications for weight management. What it actually is, at its core, is the ability of our cells to produce energy.

By providing our mitochondria with enough high-quality fuel from Pro Metabolic foods, we increase their ability to function optimally, which allows our tissues to function optimally, which allows our organs to function optimally, ultimately resulting in our entire body functioning optimally.

Over a looooong period of time, if we were to make this the foundation of our relationship with health (our “lifestyle” or “way of being” as opposed to a “diet” with a start and end point), it would improve our metabolic rate, making it possible to take in more fuel without gaining weight. The one important caveat here, which many people overlook, is that, in order to enjoy the benefits of the Pro Metabolic Diet, we must consume a surplus of fuel (in the form of calories and macronutrients) to keep the body in a positive energy balance.

This is the whole point.

Simply from a mathematical standpoint, existing in an energy surplus would make weight-loss impossible, and may even lead to weight gain in the short-term.

But this does not mean that fueling our bodies properly with an abundance of high-quality, nutrient-dense foods is something to be avoided. Metabolic Health (that is, total-body health) and weight loss are two completely different things. Either one, under the appropriate circumstances and with the right intentions and methods, can be a path to improved health.

It all depends what your goals are.

The Bottom Line?

While certain tenants of the Pro Metabolic Diet are outdated and may allow for more than a few nutritional gaps, the overarching principals would likely result in better health outcomes than the majority of fad diets out there today. And its rising popularity may even help to move the needle away from diet culture, and away from the widespread misconception that weight-loss always equals health.