Primal Cycles: The Science They're Not Connecting

Contents:

1. The Randall Cycle

2. Sugar Isn’t the Villain

3. Plants—Not Evil

4. Bringing it All Together

GLYCATION & THE RANDALL CYCLE: THE METABOLIC TRAFFIC JAM

If you've spent any time in diet debates online, you've heard the arguments:

"Carbs make you fat and sick!" "No, fat clogs your arteries!" "Keto is the answer!" "No, plant-based is the answer!"

Here's what they're both missing: it's not that fat OR carbs are bad. It's that eating high amounts of PROCESSED fats and REFINED carbs together, chronically, while sedentary, creates a metabolic traffic jam.

The Randall Cycle: Fat vs. Sugar (pick one… or choose wisely)

Your body has two primary fuel sources: glucose (from carbs) and fatty acids (from fat). It can burn either one efficiently—and when you're eating whole foods in natural combinations, it handles both just fine.

But here's where things get messy.

When you eat high amounts of both refined carbs AND industrial fats at the same time, they compete for oxidation in your muscle cells. This phenomenon was first described by Randle et al. in 1963 as the "glucose-fatty acid cycle"—now commonly called the Randall Cycle.

When glucose and fatty acids flood your system simultaneously in unnatural amounts, neither gets burned efficiently:

What happens:

• Glucose can't get burned efficiently, so it stays elevated in your blood

• Fat can't get burned either, so it gets stored

• Over time, this leads to:

  • Insulin resistance

  • Chronic inflammation

  • Fat accumulation (especially around your organs)

  • Energy crashes and cravings

But here's the key distinction: this is primarily a problem with hyperpalatable processed foods, not natural food combinations.

Glycation: When Sugar Gets Sticky

Here's the other piece of the puzzle: glycation.

When you eat sugar (or refined carbs that spike blood sugar), glucose molecules in your bloodstream start sticking to proteins and fats in your body. These sticky compounds are called AGEs (Advanced Glycation End Products), and they're exactly as bad as they sound.

Research shows that AGEs accumulate in tissues and contribute to cardiovascular disease, kidney damage, neurodegeneration, and accelerated aging (Singh et al., 2001; Vlassara & Uribarri, 2014). This is why diabetics—who have chronically elevated blood sugar—often look older and suffer complications like kidney failure, vision loss, and poor wound healing.

AGEs cause aging:

• Stiff, damaged blood vessels

• Wrinkled, sagging skin (glycated collagen)

• Kidney and nerve damage

• Brain fog and cognitive decline

In nature, sugar was seasonal. Our ancestors would encounter ripe fruit and honey in late summer—brief, intense sugar loads paired with high activity (foraging, running, climbing). The rest of the year? Definitely less, although it should be noted they would seek out carbs every chance they got.

Today? We eat sugar multiple times a day, every day. Breakfast cereal, bread, pasta, soda, "healthy" smoothies loaded with fruit. Chronic high blood sugar = chronic glycation = accelerated aging.

The Real Culprits: Processed Foods

The modern problem isn't eating an apple with some nuts. It's eating foods that combine:

• Refined carbs (white flour, sugar, high-fructose corn syrup)

• Industrial fats (seed oils, trans fats, processed dairy)

• In amounts that never exist in nature

Examples:

• Donuts (refined flour + sugar + seed oils)

• Pizza (white flour crust + industrial cheese + seed oil)

• Fries (starchy potatoes deep-fried in seed oil)

• Ice cream (sugar + industrial dairy fat)

• Pastries, cookies, cakes (refined flour + sugar + butter/margarine)

• "Balanced" meals cooked in seed oils (chicken, rice, vegetables all fried in inflammatory oils)

These combinations:

• Spike insulin AND flood your system with fat simultaneously

• Contain no fiber, no micronutrients, no satiety signals

• Are engineered to be addictive (hyperpalatable = you can't stop eating)

• Are consumed chronically, year-round, multiple times daily

This is what wrecks your metabolism. Not eating steak and berries in the same meal.

Natural Food Combinations are FINE and (Possibly?) Optimal

Here's what the Randall Cycle fear-mongering gets wrong:

Traditional cultures have been eating natural combinations of fat and carbs for millennia—and they were metabolically healthy:

• Hadza tribe (Tanzania): lean game + honey (they get 15-20% of calories from honey during peak season, paired with lean meat and organs)

• Coastal tribes (Pacific Northwest, Polynesia): fatty fish + fruit (salmon with berries, fish with tropical fruit)

• Mediterranean cultures: olive oil + fruit/vegetables + lean protein

• Inuit (in summer): lean caribou + berries (when available)

Why these combinations work:

✅ Whole foods, not processed (no refined carbs, no seed oils)

✅ Natural satiety signals (fiber, water content, micronutrients tell you when to stop)

✅ Paired with activity (foraging, hunting, walking, swimming—not sitting at a desk)

✅ Paired with sunlight (vitamin D optimizes glucose metabolism)

✅ Mostly seasonal (not eaten year-round in the same amounts)

✅ Moderate amounts (you can't overeat whole foods the way you can processed foods)

Meat & fruit, for instance, is a fantastic long-term strategy—even year-round for some people. It combines many of the benefits of carnivore (nutrient density, gut healing, satiety), primal (whole foods, nose-to-tail), and paleo (evolutionary alignment) diets.

Does it suffer from some of their drawbacks? Maybe. Some people might do better with more seasonal variation. Some might need more fat in winter or fewer carbs year-round. Each individual needs to monitor how they're reacting over weeks, months, and years—not just momentary feelings.

But the idea that you can't eat meat and fruit together because of the Randall Cycle? That's dogma, not science.

NOTE: keep in mind these populations are exceptionally active. This is a key factor that often gets overlooked in modern nutrition circles.

The Real Issue: Chronic Consumption + Processed Foods + Sedentary Lifestyle

The Randall Cycle becomes a problem when you combine:

❌ Processed, hyperpalatable foods (refined carbs + industrial fats)

❌ Chronic, year-round consumption (no variation, no cycling)

❌ Sedentary lifestyle (sitting at desks, in cars, on couches)

❌ Artificial light (disrupts circadian rhythm and glucose metabolism)

❌ No seasonal variation (eating the same foods in the same amounts year-round)

Remove those variables, and the Randall Cycle is a non-issue.

Eat whole foods. Move your body. Get sunlight. Cycle your fuel sources seasonally (or find a natural combination that works for you long-term). Listen to your body over weeks and months, not just hours.

Why Cycling Still Makes Sense (but isn’t the Only Way)

Here's what seasonal cycling gives you:

• Spend winter eating high-fat, low-carb (carnivore) → your body becomes efficient at burning fat

• Shift to moderate carbs in spring (pescatarian with some fruit) → you maintain metabolic flexibility

• Ramp up carbs in summer (fruit, honey, lean meat) → your body burns glucose efficiently because you haven't been doing it year-round

• Fall brings balance (fattier meats + starches) → smooth transition back to fat-burning

You never get stuck in one mode long enough to develop insulin resistance OR thyroid down-regulation.

Your body stays flexible. Your metabolism stays responsive. You avoid the pitfalls of chronic anything.

But is it the ONLY way? No.

Some people thrive on year-round meat & fruit. Some people do best with year-round carnivore (adding carbs only around training). Some people need more seasonal variation.

The key: Whole foods. Activity. Sunlight. Self-awareness. Experimentation over time.

This is how our ancestors ate—not by following a rigid plan, but by responding to their environment and listening to their bodies.

Randall Cycle Wrap-up

• The Randall Cycle is real—fat and carbs compete for oxidation when both are present in high amounts

• The problem is PROCESSED foods (refined carbs + industrial fats in unnatural combinations)

• Natural food combinations are fine (meat & fruit, fish & berries, etc.)—traditional cultures ate this way and thrived

• Chronic consumption + sedentary lifestyle is the real issue—not the foods themselves

• Seasonal cycling is ONE strategy—but not the only one (meat & fruit year-round works for many people)

• Monitor yourself over time—weeks, months, years (not just how you feel after one meal)

• Whole foods + movement + sunlight + self-awareness = the foundation

Don't let Randall Cycle fear-mongering scare you away from natural, ancestral food combinations. The science is being misapplied.

Sugar Isn't the Villain (Context Is)

Sugar has been demonized. Keto and carnivore communities treat it like poison. And I get it—chronic sugar consumption IS wreaking havoc on modern health.

But here's what they're missing: the problem isn't sugar itself. It's eating it year-round, in massive quantities, while sitting on our asses under artificial light. When you’re already metabolically f*cked and inflamed, of course carnivore is the answer for that person and in that moment.

Short-Term Sugar Floods Are Actually Healthy (Gasp!)

Our ancestors didn't avoid sugar. They gorged on it—when they could find it.

Stumble upon a beehive? Consume pounds of honey in one sitting. Find a grove of ripe fruit in late summer? Eat until your stomach hurts. Then go weeks or months without seeing another gram of fructose.

This isn't a glitch. It's a feature.

Acute sugar spikes (when paired with activity and sunlight) actually:

• Refill muscle glycogen rapidly

• Improve insulin sensitivity (when you cycle in and out of carbs, not stay chronically high)

• Boost serotonin and mood

• Support thyroid function (T3 conversion improves with strategic carb intake after low-carb periods)

The difference? These sugar loads happened in context:

• Peak sunlight (12-16 hours of summer sun)

• Maximum activity (foraging, climbing, running, swimming)

• High energy demands (your body NEEDED that glucose)

Today? We eat sugar:

• Year-round (mangoes in January, bananas shipped from Ecuador)

• Multiple times daily (cereal, sandwich bread, snacks, dessert)

• While sedentary (sitting at desks, in cars, on couches)

• Under artificial light (which disrupts glucose metabolism)

Your body is built to handle sugar spikes followed by sugar droughts. What it CAN'T handle is the relentless, year-round drip.

The Vitamin D Factor

Here's something most people don't connect: your ability to process sugar is directly tied to sunlight.

Vitamin D (which your skin produces from sun exposure) acts as a hormone that regulates insulin sensitivity. Multiple studies confirm this: vitamin D deficiency is directly linked to insulin resistance and impaired glucose tolerance (Mitri & Pittas, 2014; Berridge, 2017). When your D levels are high—like they would be in summer—your body handles glucose efficiently. When they're low—like in winter—your insulin sensitivity drops.

When your D levels are high—like they would be in summer—your body handles glucose efficiently.

The natural pattern:

• Summer: Maximum sun → high vitamin D → body thrives on fruit and honey

• Winter: Minimal sun → low vitamin D → body shifts to fat metabolism

The modern disaster: We eat the same carbs (or more) in December as we do in July, but our vitamin D levels are in the basement. We're asking our bodies to process glucose without the hormonal infrastructure to do it.

Summer sun? High carbs. Winter darkness? High fat. Your hormones follow the light.

Sugar Fasting: The Reset Button

Here's a concept most people miss: periodic sugar restriction restores insulin sensitivity.

When you go weeks or months without sugar (like you would in winter on a carnivore approach), your cells become "hungry" for glucose again. Insulin receptors upregulate. When you DO reintroduce carbs (spring/summer), your body responds beautifully.

Contrast this with year-round sugar consumption: Your cells are constantly bathed in insulin. Over time, they stop listening (insulin resistance). You need more and more insulin to get the same effect. Eventually: type 2 diabetes, metabolic syndrome, chronic inflammation.

The seasonal approach:

• Summer: eat fruit and honey liberally (2-3 months)

• Fall: transition to starches, reduce simple sugars

• Winter: near-zero sugar (carnivore reset, 2-3 months)

• Spring: reintroduce moderate natural sugars

NOTE: this idea is based on temperate climates, adjust according to the weather patters!

You never feel deprived. You never "cheat." You just follow the rhythm.

Modern Fruit Isn't Ancient Fruit

One more thing: the fruit you buy at the grocery store isn't what your ancestors ate…

Wild strawberries are tiny, tart, and rare. Modern strawberries are huge, candy-sweet, and available 12 months a year.

Wild apples are small and sour. Modern apples have been bred for sugar content.

Bananas didn't even exist in their current form until human cultivation and they’re all clones of one strain!

This doesn't make fruit bad—but it does mean we need to be smarter:

• Eat local, in-season fruit only (no tropical imports in winter)

• Watch quantity (a handful of berries ≠ a smoothie with 3 bananas and mango)

• Pair with activity (not as a desk snack)

HOWEVER, there is also an argument to be made that we have simply optimized these fruits and that survival in nature / historically didn’t equate to the healthiest states humans can achieve. I think this point often gets overlooked by zealots of low carb circles.

Bottom line: sugar in its natural form, in short bursts, paired with sunlight and movement, is not only safe—it's beneficial. The problem is we've removed all the context and turned it into a year-round staple.

Cycle it. Respect it. Don't fear it.

Plants—Not Evil, Just Complicated

Let's talk about vegetables. The mainstream narrative is simple: plants = good, meat = bad. Eat more salads. Drink green smoothies. Load up on fiber.

But if you've ever felt worse after eating "healthy" foods—bloated after a kale salad, joint pain after spinach, gut distress after beans—you're not crazy. And you're not alone.

This paradigm has led many in the carnivore community to make a blanket admonishment of all plant foods and I don’t blame them—I was exposing this idea in the beginning of my journey too.

Here's the truth: plants aren't evil. But they're not the panacea of health we've been told they are.

Modern Plants Aren't Ancient Plants

Almost every vegetable you eat has been selectively bred over thousands of years to be bigger, sweeter, and more palatable.

Wild cabbage became broccoli, kale, cauliflower, and brussel sprouts (all the same species). Wild carrots were thin, bitter and purple. Corn was a small grass called teosinte with hard kernels. Wheat has been hybridized so heavily that modern gluten is, structurally, completely different from ancient einkorn.

Perhaps this is a good thing, just like fruits which we’ve “optimized”.

What this means: some of these plants contain higher concentrations of certain compounds and have been optimized for yield—NOT nutrient density or digestibility.

Your genetics may be adapted to the plants your ancestors ate 10,000 years ago, but NOT to the Franken-vegetables bred in the last century.

Plant Defense Chemicals (Why Plants Fight Back)

Here's something they don't teach in nutrition class: plants don't want to be eaten.

Unlike animals (which can run or fight), plants evolved chemical defenses to discourage predation. These aren't "toxins" in the acute sense—you won't drop dead from eating spinach. But they CAN cause problems, especially if your gut is already damaged.

Research shows that compounds like lectins can increase intestinal permeability in susceptible individuals (Freed, 1999), oxalates contribute to kidney stones and joint issues (Mitchell et al., 2019), and phytates significantly reduce mineral absorption (Schlemmer et al., 2009). The dose—and the state of your gut—makes the poison.

The main offenders:

Lectins:

• Proteins that bind to your gut lining and can cause intestinal permeability ("leaky gut")

• Found in: beans, lentils, grains, nightshades (tomatoes, peppers, eggplant)

• If your gut is healthy: you might tolerate them fine

• If your gut is damaged: they can trigger autoimmune reactions, inflammation, and digestive chaos

Oxalates:

• Compounds that bind to minerals (calcium, magnesium) and form sharp crystals

• Can contribute to kidney stones, joint pain, and mineral deficiencies

• Found in: spinach, chard, beet greens, almonds, sweet potatoes

• If your gut is healthy: you excrete them efficiently

• If your gut is damaged: they accumulate in tissues and cause problems

Phytates (Phytic Acid):

• "Anti-nutrients" that bind to minerals (iron, zinc, calcium) and prevent absorption

• Found in: grains, beans, nuts, seeds

• Traditional preparation (soaking, sprouting, fermenting) reduces phytates

• Modern shortcuts (instant rice, quick-cook oats) leave them fully intact

The dose makes the poison.

Small amounts, occasionally, with a healthy gut? Probably fine. Large amounts, daily, with a compromised gut? Chronic inflammation, nutrient deficiencies, autoimmune flare-ups.

The Gut Health Variable (This Changes Everything)

Here's what most people miss (if your gut is healed and your microbiome is balanced):

• You produce enzymes that break down plant compounds

• Your gut lining is intact (no leaky gut)

• You tolerate fiber well

• Plants can provide beneficial antioxidants, polyphenols, and prebiotic fiber

If your gut is damaged (leaky gut, dysbiosis, IBS, autoimmune conditions):

• Plant defense chemicals slip through your gut lining into your bloodstream

• Your immune system attacks them (and sometimes your own tissues by mistake)

• Fiber ferments and causes bloating, gas, pain

• You feel WORSE eating "healthy" salads and vegetables

This is why some people thrive on plant-heavy diets and others feel like death. It's not about the plants themselves. It's about the state of YOUR gut.

This is also why the carnivore reset works: you remove all plant compounds, heal your gut lining, restore your microbiome balance. THEN you can strategically reintroduce plants and see what you actually tolerate.

If you're reacting to everything, your gut isn't ready. Heal first. Experiment later.

Seasonal Plant Consumption (The Ancestral Pattern)

Your ancestors didn't eat the same vegetables year-round. They ate plants when available, in season, and often after careful preparation.

The natural rhythm:

• Winter: almost no plants (maybe some fermented vegetables, stored root vegetables)

• Spring: early greens, shoots, wild herbs (small amounts, nutrient-dense, often bitter)

• Summer: leafy greens, some vegetables, abundant fruit

• Fall: starchy tubers, squash, root vegetables (energy-dense for winter preparation)

The modern disconnect: We eat the same vegetables 365 days a year, often raw, often in massive quantities (because "eat more plants").

We're eating out-of-season produce shipped from across the globe. Spinach in December. Tomatoes in February. Kale smoothies every single morning.

The pattern becomes clear:

• Winter carnivore phase: gives your gut a complete break from plant compounds, heals the intestinal lining, reduces systemic inflammation

• Spring reintroduction: once your gut is healed, you can tolerate (and benefit from) small amounts of early greens and herbs

• Summer variety: with a healthy gut, seasonal vegetables and fruits provide antioxidants and fiber without the inflammatory response

• Fall starches: root vegetables and squashes provide glucose and comfort without the lectin/oxalate load of year-round leafy greens

You're not avoiding plants forever. You're eating them when your body is ready and when they're naturally available.

Preparation Matters (What Traditional Cultures Knew)

If you're going to eat plants, how you prepare them is just as important as which ones you choose. Traditional cultures understood this instinctively:

• Fermenting (sauerkraut, kimchi, sourdough) = breaks down plant defenses, adds probiotics, increases bioavailability

• Soaking (beans, grains, nuts) = reduces lectins and phytates significantly

• Sprouting (seeds, legumes, grains) = neutralizes anti-nutrients, increases vitamin content

• Cooking (especially pressure cooking) = deactivates many lectins and makes nutrients more accessible

Modern food culture skips all of this:

• Canned beans straight from the can (not soaked, not fermented)

• Instant rice and quick-cook oats (no preparation)

• Raw kale smoothies (lectins and oxalates fully intact)

• Almond milk made from unsoaked almonds (phytates and oxalates concentrated)

If you're going to include plants in your seasonal rotation, prepare them the way your great-grandmother would have:

• Soak your beans overnight before cooking

• Ferment your vegetables

• Cook your greens (don't just eat them raw)

• Pressure cook high-lectin foods like beans and nightshades

Plants in Perspective

1. Plants aren't poison. But they're not a panacea either.

2. If your gut is damaged: plants (especially raw, unprepared, high-lectin plants) can make things worse. Start with carnivore. Heal your gut. Then experiment.

3. If your gut is healthy: seasonal, properly-prepared plants can add variety, flavor, and beneficial compounds to your diet—especially in spring and summer when they're naturally abundant.

4. But here's the key: you don't NEED plants to be healthy. There's no essential nutrient in plants that you can't get from animal foods (and often in more bioavailable forms). Plants are optional. Meat is not.

5. Think of plants as a seasonal bonus, not a dietary foundation. eat them when they're in season. Prepare them properly. Listen to your body. If something makes you feel like garbage, don't eat it—no matter how "healthy" the internet says it is.

6. Your gut gets the final vote.

BRINGING IT ALL TOGETHER: THE SCIENCE BEHIND SEASONAL EATING

Now you understand the mechanisms.

The Randall Cycle isn't about fearing natural food combinations—it's about recognizing that processed foods combining refined carbs and industrial fats create metabolic chaos. Meat and fruit? Fine. Donuts and fries? Disaster. The difference is whole foods vs. processed garbage, activity vs. sedentary lifestyle, and seasonal variation vs. chronic consumption.

Glycation and AGEs show us why chronic sugar consumption accelerates aging—but also why short-term sugar floods paired with sunlight and activity are perfectly healthy (and even beneficial). Your ancestors gorged on honey and fruit in summer, then went months without it. Your body expects this rhythm.

Sugar isn't the villain—context is. Eat it seasonally. Pair it with sun and movement. Cycle in and out. Your insulin sensitivity will thank you.

Plants aren't evil—but they're complicated. If your gut is damaged, they can trigger inflammation. If your gut is healthy, they provide variety and micronutrients. The ancestral pattern? Almost none in winter (gut reset), moderate amounts in spring/summer (when your gut is healed and they're naturally available). Prepare them properly. Listen to your body. They're optional, not essential.

The Pattern Emerges

Do you see it now?

Every piece of the puzzle points to the same truth: Your body is designed to CYCLE, not stay static.

• Cycle between fat-burning and glucose-burning (avoid chronic reliance on either)

• Cycle between animal foods and plant foods (not 100% of either, year-round)

• Cycle between feasting and fasting (abundance and scarcity)

• Cycle between high activity and rest (summer output, winter recovery)

The modern world removed all variation. We eat the same foods, in the same amounts, at the same times, every single day—under artificial light, in climate-controlled buildings, with zero connection to the seasons.

And we wonder why we're sick.

Seasonal eating restores the rhythm your biology expects.

What’s Next?

You understand the WHY (Article 1: the diet wars, why every diet fails, why seasonal eating solves it).

You understand the SCIENCE (Article 2: Randall Cycle, glycation, sugar, plants).

Now it's time for the HOW.

In the next article, I'll break down the complete seasonal eating framework:

• Winter: The Carnivore Phase (what to eat, why it works, what to expect, how long to run it)

• Spring: The Pescatarian/Transition Phase (cleansing, renewal, reintroducing variety)

• Summer: The High Carb Phase (fruit, honey, peak performance, maximum sun)

• Fall: The Balanced/Preparation Phase (bridging abundance and scarcity, preparing for winter)

You'll learn:

• Exactly what to eat in each season (with real-world examples from my own experiments)

• Why each phase works (tribal examples, modern application)

• What to expect (energy, digestion, training, common issues)

• When to transition (signs your body is ready for the next phase)

This is where theory becomes practice.