Fat Is Fuel for Life – Why Your Brain, Energy and Longevity Depend on It

Let’s get one thing straight:
The body’s primary energy system is aerobic.
And the primary fuel for the aerobic system is fat, period.

If it weren’t for fat, humans would never have evolved into what we are today.

🧠 Fat and the Brain

Our brains only make up about 2% of our total body weight, yet they consume 20–25% of our total energy.
Fat is not only the most energy-dense nutrient—but animal fat in particular is also nutrient-dense.
Our brains started growing in size and complexity the moment we gained access to dietary fat.

🥇 My Top 5 Fats for Health and Energy

1. Marrow fat / Tallow

A beautiful spectrum of fatty acids:
50% monounsaturated fat, 20% stearic acid, plus linoleic acid, CLA, and vitamins K, A, D, and E.

2. Butter

Another diverse fat profile, with:
Butyrate (supports gut flora and immunity), CLA, and fat-soluble vitamins K, A, D.

CLA (conjugated linoleic acid) deserves special mention: it’s anti-inflammatory, supports fat metabolism, and helps preserve muscle. I also take it as a supplement.

3. Fish Oil

Rich in essential fatty acids (EPA + DHA) crucial for brain and heart function.

4. Olive Oil

Contains 70–80% oleic acid (monounsaturated) and potent polyphenols with antioxidant effects.
Studies have shown that when two groups eat the same number of calories—but one consumes more olive oil—they tend to lose more weight.

5. Dairy (especially from sheep/goat)

Loaded with vitamin K2, CLA, and high levels of short-chain and some MCT fats.
Particularly rich in pentadecanoic and heptadecanoic acids—two lesser-known fats associated with longevity (just look at Sardinia).
So yeah, if you’re wondering why I eat so much pecorino and feta… 🙄

🫧 Honourable Mention: Coconut