Ray Peat’s Bioenergetic Theory for Diet & Why Energy is Everything

Healing Concepts
Written By Ivy Ham

More Than Just Calories

Many diets today zero in obsessively on calorie counting or cutting carbs, but what if the secret to true health was something far simpler yet more profound? Ray Peat, the visionary biologist behind the bioenergetic theory of health, argues that energy—not calories—is the fundamental key to wellness. His philosophy turns conventional diet wisdom on its head, shifting the focus from deprivation and restriction to optimizing cellular energy production.

Personally, I've always disliked calorie counting. Constantly weighing and tracking every bite feels tedious, especially since I prefer cooking my own meals from scratch and usually don’t follow a recipe. It turned preparing and enjoying food—something naturally fun and nourishing—into a chore. This made me wonder: how did our ancestors, who maintained strong, resilient physiques, manage without ever counting a single calorie? Clearly, there was something they intuitively understood about health that modern diet culture has overlooked.

In Ray Peat’s bioenergetic model, health revolves around robust cellular energy production, especially ATP, the energy currency produced by our mitochondria. Every vital function in your body—from metabolism and hormonal balance to mood, cognition, and physical resilience—depends on the efficiency of your cells' energy production. Think of your body as a furnace: Ray Peat wants you to stoke that furnace bright and hot, not dim it down through restriction.

This bioenergetic perspective resonates deeply with anyone frustrated by the limitations and diminishing returns of mainstream diets like keto or calorie counting. By embracing a high-energy, metabolism-supporting lifestyle, we work with our biology rather than against it, restoring the warmth, vitality, and overall wellness that traditional dieting methods often undermine.

Who is Ray Peat? – The Biologist Behind the Bioenergetic Theory

Raymond Peat, PhD, is an American biologist whose work spans physiology, endocrinology, and nutrition. For more than fifty years he focused on a practical question: How can we keep the body’s energy‑producing machinery working at its best? His answer—often called the bioenergetic approach—centers on supporting the mitochondria so they can convert food into ample, steady energy.

The Bioenergetic idea

Mitochondria transform carbohydrates, fats, and proteins into adenosine triphosphate (ATP), the chemical energy every cell needs. Peat argues that when ATP production slows, metabolism drags, stress hormones rise, and health declines. Diet and lifestyle choices that favor robust, efficient energy output—adequate carbohydrates, balanced protein, thyroid support, and manageable stress—help maintain body temperature, mood, and overall resilience.

Influence of Gilbert Ling

Peat builds on the work of biophysicist Gilbert Ling, who described cells as structured gels rather than simple fluid‑filled sacs. In this model ATP is more than fuel; its constant presence helps stabilise the cell’s structure. Ensuring a steady supply of energy therefore becomes essential for both cellular integrity and function.

Why people look to Peat’s work

Many readers arrive at Peat after trying restrictive diets that left them cold, fatigued, or anxious. Peat proposes a different route: nutrient‑dense, easily digested foods—ripe fruit, quality dairy, root vegetables, adequate protein—paired with sufficient salt, bright light, and regular meals. The overarching goal is straightforward: support metabolism rather than suppress it.

Peat’s articles are rich with citations from basic science, yet his core message remains clear: when you provide your mitochondria with what they need, the entire system has a better chance to thrive.

Mitochondria, ATP, and “Why Energy is Everything”

Let’s take a little detour back to high school biology class: Mitochondria (aka the powerhouse of the cell) combine nutrients and oxygen to produce adenosine triphosphate (ATP)—the body’s primary energy carrier. In Ray Peat’s model, health rises or falls with how well these “power plants” keep ATP flowing.

When oxygen is available, oxidative phosphorylation turns one glucose molecule into about 32 ATP, releasing only carbon dioxide and water as by‑products. If oxygen, thyroid hormone, or key nutrients run short, cells switch to anaerobic glycolysis, yielding just 2 ATP and excess lactic acid—less energy with more metabolic “clutter.”

Because every tissue depends on ATP, efficient mitochondrial output supports clear thinking, steady mood, and physical stamina. A drop in cellular energy—say after prolonged fasting or exposure to cold—quickly shows up as fatigue, irritability, and brain‑fog. Restoring fuel, warmth, and oxygen lets oxidative metabolism resume and performance rebound.

The Bioenergetic Diet

Ray Peat treats food first and foremost as fuel for your cellular engines. Instead of counting every calorie or avoiding whole nutrient groups, the bioenergetic diet focuses on foods that are easy to digest, rich in vitamins and minerals, and gentle on the thyroid and liver—two organs that set the pace of your metabolism.

1. Carbs Are So Back!!!

  • Choose whole‑food sugars: ripe fruit, fresh orange juice, honey, well‑cooked roots and tubers, and the lactose naturally present in milk.

  • Why it matters: These forms of fructose + glucose refill liver glycogen and keep blood sugar steady, which helps curb that mid‑afternoon cortisol surge. Your brain runs on glucose, so opting for low carb diets can place additional stress on your liver to convert glycogen to glucose. People who eat plenty of fruit often show better insulin sensitivity and lower inflammatory markers.

  • A practical upside: fruit and honey add sweetness without the energy crash that can follow pastries or other refined starches.

2. Saturated Fats >>>> Seed Oils

  • Use: butter, ghee, coconut oil, dairy fat, and the fat that comes with ruminant meats (beef, lamb, etc).

  • Limit / Avoid: soybean, corn, canola, sunflower, and most nut‑seed oils (including most store‑bought mayonnaise, dressings and oil-based condiments).

  • Reasoning: Saturated fats are chemically stable at body temperature. Large amounts of omega‑6 seed oils, by contrast, tend to raise inflammation and can slow thyroid activity over time, negatively impacting hormones and metabolism.

3. Easy to Digest Protein

  • Aim for roughly 80–100 g per day, adjusted to body size and activity.

  • Opt for: dairy, eggs, shellfish, and collagen‑rich foods such as bone broth or gelatin. The glycine in gelatin balances the higher‑methionine profile of muscle meat and is soothing to the gut. Glycine also is supportive for sleep.

4. Micronutrients

  • Liver and shellfish supply copper, zinc, and vitamin A.

  • Milk and cheese deliver highly absorbable calcium, helpful for nerve calm and thyroid conversion of T4→T3.

  • Fruit and coffee (in moderation) provide potassium, vitamin C, and gentle metabolic stimulation.

Together, these foods give mitochondria the minerals and cofactors they need for smooth energy production.

5. What Dr. Peat puts on the back burner

Skipping meals, long fasts, very‑low‑carb plans, and large bowls of raw cruciferous greens. Extended carb restriction can push thyroid hormone (T3) down and leave people feeling cold, sluggish, and easily fatigued. Regular meals that combine natural sugars, quality protein, and stable fats keep the metabolic fire steady.

Here’s a chart showing common foods:

✅ Supports Metabolism ⚠️ Avoid / Use Sparingly
🍊 Fresh fruit & juices 
(orange, pineapple, ripe mango, grapes) 		🛢️ Industrial seed oils 
(soy, corn, canola, cottonseed, grapeseed)
🍯 Natural sweeteners 
(raw honey, maple syrup, date syrup) 		🍩 Refined pastries & desserts 
(doughnuts, iced cakes, packaged cookies)
🥛 Full‑fat dairy 
(whole milk, yogurt, kefir, cheese, ice cream made with cream) 		🥤 Artificial sweeteners & diet drinks 
(sucralose, aspartame, diet soda)
🥩 Ruminant meats, eggs & shellfish 
(grass‑fed beef, lamb, eggs, oysters, crab) 		🍗 High‑PUFA animal options 
(skinless chicken, turkey deli slices, bacon)
🍲 Broth & gelatin 
(bone broth, collagen powder, oxtail stew, pork‑skin gelatin) 		🥜 Nuts & nut butters 
(almonds, peanuts, mixed‑nut bars, almond butter)
🧈 Stable cooking fats 
(butter, ghee, coconut oil, cacao butter) 		🐟 Fish‑oil capsules & PUFA spreads
🥔 Roots & tubers 
(potatoes, carrots, beets, squash, plantains) 		🥯 White‑flour snack foods 
(bagels, crackers, pretzels)
☕ Coffee & dark chocolate 
(≥ 80 % cacao bars, cacao nibs) 		🍫 Candy bars with seed‑oil fillers & HFCS
🦴 Mineral‑rich organs & extra shellfish 
(liver, heart, mussels, clams) 		🥬 Large raw kale / crucifer salads & green‑juice detoxes
⏰ Regular balanced meals & snacks ⏳ Chronic fasting, prolonged keto, OMAD

Hormonal Balance Through Bioenergetics:

Thyroid, Stress Hormones, and More

Thyroid – The Metabolic Master Switch

At the core of Peat’s high-metabolism model is the thyroid gland. Its primary hormone, T3 (triiodothyronine), sets the pace for cellular energy production. When thyroid function is strong, you stay warm, alert, emotionally stable, and metabolically efficient. When it’s underactive, common symptoms include:

  • Cold extremities

  • Fatigue or low motivation

  • Weight gain, slowed digestion

  • Depression or apathy

  • Elevated cholesterol

Peat emphasized tracking morning body temperature and resting pulse as practical indicators of thyroid function. A waking temp below 98°F and a low pulse may reflect reduced metabolic activity, even when standard labs appear “normal.”

Supporting the thyroid nutritionally (e.g., through dairy, shellfish, liver, and sufficient carbs) and minimizing stress load are foundational steps. In some cases, thyroid glandulars are used to restore optimal function—always alongside regular monitoring.

Literature Link: Research shows T3 supports mitochondrial biogenesis, brain development, and neuroplasticity—further validating Peat’s view that thyroid health underpins total body function.

Stress Hormones – Cortisol & Adrenaline

If you like to drink coffee in the morning before eating breakfast, you need to consider how that may be affecting your hormones and thyroid. In a low-energy state, the body relies more heavily on stress hormones to compensate. Cortisol and adrenaline help maintain blood sugar by breaking down tissues (muscle, fat, even bone) for fuel. Over time, this leads to:

  • Muscle wasting

  • Fat gain (particularly visceral)

  • Anxiety, irritability, and poor sleep

  • Suppressed thyroid output

  • Blood sugar instability

Ray Peat viewed chronic stress hormone activation as a sign of metabolic failure, not resilience. He advocated for regular intake of easily digestible sugars (like ripe fruit, fruit juice, honey) to supply glucose directly, reducing the need for cortisol-driven catabolism.

Evidence: Studies confirm that carbohydrate restriction increases cortisol levels, while refeeding with carbs reduces it—supporting Peat’s view that sugar, in context, can be anti-stress.

Sex Hormones – Progesterone, Testosterone, Estrogen, and Prolactin

When thyroid function and blood sugar stability are supported, the body tends to produce higher levels of protective sex hormones:

  • Progesterone – calming, pro-metabolic, supports fertility

  • Testosterone – supports strength, libido, and motivation

  • Estrogen and Prolactin – regulated to healthy levels, preventing excess

Peat associated excess estrogen and prolactin with inflammation, tissue growth disorders, and stress physiology. Many women using Peat’s principles report better menstrual cycles and mood stability. Men often notice improved drive, lean mass retention, and emotional steadiness.

Dopamine vs. Serotonin – Metabolic Influences on Mood

Peat challenged the mainstream narrative that serotonin is always “good.” He argued that elevated serotonin can reflect chronic stress, inflammation, and low energy availability—similar to a hibernation state.

Dopamine, by contrast, is associated with movement, focus, and reward. In well-nourished, high-energy states, dopamine tends to rise while serotonin normalizes. The result: clearer thinking, improved motivation, and emotional resilience.

Mechanistic Insight: Metabolic health influences neurotransmitter dominance—supporting Peat’s broader theory that energy availability regulates not only hormones but also brain chemistry.

Lifestyle Choices for a High-Energy Life: Beyond Diet

A truly high-energy lifestyle goes beyond what’s on your plate—it’s also about how you move, rest, and interact with your environment. Ray Peat emphasized that stress is one of the most potent suppressors of metabolism, and the way you live each day plays a huge role in your body’s ability to produce and maintain energy.

Manage Stress & Ensure Recovery

Chronic psychological stress can impair mitochondrial function, dragging down your cellular energy output. One of Peat’s key insights was that stress and mitochondrial health are deeply connected. That’s why he recommended prioritizing rest, sleep, and activities that help your nervous system unwind.
Instead of extreme workouts that spike cortisol, opt for slow walks, afternoon naps, or creative hobbies. These activities downshift your body from a stress-dominant mode into a more restorative, energy-efficient stat where healing and vitality flourish.

Temperature and Environment

Feeling cold all the time? That’s often a sign your metabolism is underperforming. Ray believed that warmth supports energy production, and cold stress does the opposite. Simple steps like wearing socks, layering up in colder months, or avoiding icy environments can reduce your metabolic burden.
Some followers even use warming tools—like infrared lamps directed at the thyroid or warm baths—to support circulation and energy. These aren’t essential, but they can be effective for those needing a gentle metabolic nudge.

Light and Circadian Rhythm

Light is one of your body’s most powerful metabolic regulators. Morning sunlight helps synchronize your circadian rhythm and naturally lowers daytime melatonin levels—prepping you for better sleep at night.
Peat also spoke highly of incandescent and red-spectrum light, which have been shown in studies on photobiomodulation to support mitochondrial function. Try sitting by a sunny window in the morning or switching to red lights in the evening to help restore your natural rhythms.

Breathing and CO₂

Peat took a unique view on carbon dioxide—not as waste, but as a vital product of healthy energy metabolism. CO₂ improves oxygen delivery to tissues and has calming effects on the nervous system.
To increase CO₂ naturally, practice slow, diaphragmatic breathing, like what you’d find in yoga or meditation. In more advanced cases, Peat even suggested “bag breathing,” but the principle is simple: relaxed breathing = better oxygenation = more energy.

Avoid Toxins & Anti-Metabolic Stressors

Living a high-energy life also means avoiding common metabolic blockers. This includes cutting out seed oils high in polyunsaturated fats (PUFAs), limiting exposure to xenoestrogens in plastics and personal care products, and avoiding overtraining.
Instead, choose moderate resistance training to build muscle and boost resting metabolism. Most importantly, build a life you enjoy—because consistent joy and fulfillment lower stress hormones naturally.

Bioenergetic Theory vs. Conventional Diets

From Restriction to Nourishment

Conventional dieting often revolves around “eat less, move more,” but long-term it leaves many cold, tired, and frustrated. Ray Peat’s research is so interesting because it totally changes the idea around how to lose weight: nourish the body to raise metabolic rate so you burn more at rest. Chronic dieting raises cortisol and can suppress metabolism—Peat’s approach does the opposite by supporting energy production.

For the Low-Carb Burnouts

Low-carb and keto can work short-term, but many hit a wall—fatigue, low mood, hormonal issues. Peat invites people to reintroduce fruit, juice, dairy, even sugar (in context) to restore energy and thyroid function. The result? More warmth, better moods, and often easier fat loss once stress hormones drop.

Holistic, Not Reductionist

Rather than demonizing nutrients like sugar or fat, Peat focuses on metabolic context. Sugar isn’t the problem—pairing it with junk and bad fats is. His view resonates with those tired of oversimplified “good vs bad” nutrition advice.

Why It Sticks

There’s a growing movement of ex-dieters crediting bioenergetics for better energy, skin, mood, and metabolism—not just weight changes. It’s not about just calories anymore—it’s about feeling good.

Putting Bioenergetics into Practice

Eat Balanced Meals Frequently
Don’t run on empty. Regular meals with protein, carbs, and fat keep blood sugar steady and stress hormones low. Think: eggs and orange juice for breakfast, milk or cheese as a snack, and fruit or root veggies over plain bread.

Daily Pro-Metabolic Foods
Incorporate foods that support metabolism and lower stress:

  • Orange juice – boosts liver function and provides easy carbs

  • Raw carrot – helps detox estrogen and other hormones and supports gut health

  • Bone broth/gelatin – rich in glycine, soothing for digestion

  • Coconut oil – easy-to-metabolize fat

  • Oysters – high in zinc and selenium for thyroid support
    Even dark chocolate can help—magnesium, sugar, and pleasure all reduce stress. Oysters are probably not for every day, maybe once per week or so.

Support the Thyroid
Get iodine and selenium from dairy, eggs, seafood, and Brazil nuts. Avoid extreme low-carb—your liver needs glycogen to convert thyroid hormone (T4 → T3). If needed, track waking temp/pulse or consider natural thyroid support with a practitioner.

Optimize Daily Habits
Manage stress with light movement, sunlight, warm baths, and good sleep. Breathwork or calm mornings raise CO₂, which helps oxygenation and energy. Moderate, enjoyable movement (like a walk) beats high-stress workouts.

Track Biofeedback
Dr. Peat promoted simple tracking: Morning basal body temps near 98.6°F and pulse 75–90 bpm suggest good thyroid function. Better digestion, libido, warmth, and restful sleep are all green lights. Adjust food, salt, or protein if your blood sugar feels unstable.

Individualize It
Ray Peat’s principles aren’t dogma. It’s important to listen to your bodys signals always. Coming off keto? Add carbs back in gradually. Can’t tolerate dairy? Use fruit, roots, and gelatin. The goal: sustainable, nourishing choices that energize your cells and reduce stress.

Final Thoughts

Ray Peat’s bioenergetic perspective encourages a shift from restrictive, stress-driven approaches to one that prioritizes cellular energy and metabolic support. Rather than seeing food as something to limit, this view recognizes nourishment—especially in the form of pro-metabolic foods, rest, warmth, and light—as essential to healthy function.

The research supporting this energy-first model, alongside Peat’s own insights, suggests that when we focus on supporting mitochondrial function and metabolic rate, we often see broader improvements—in hormone balance, mental clarity, and overall resilience.

If you’re curious, you don’t need to overhaul everything. Something as simple as tracking your morning temperature or reintroducing fruit can offer insight into how your body responds. The idea is to build awareness and work with your biology, rather than against it.

Whether you're questioning past dietary advice or just looking for a more sustainable foundation for health, the bioenergetic framework offers a useful lens—one centered not on deprivation, but on supporting life at its most basic level: through energy.

Ivy Ham

I’m Ivy Ham, a clinical herbalist dedicated to blending traditional healing wisdom with modern science, and revealing how nature’s remedies can enhance everyday wellness. Through my blog, I share insights on herbal solutions, nutrition, and holistic practices to guide you toward a more balanced, vibrant life.

Next

Is Red Meat Healthy? Here’s What “The Science” Says