Key facts
- The most calorie-dense macro at 9 kcal per gram.
- Essential for hormone production, including testosterone.
- Needed to absorb fat-soluble vitamins (A, D, E, K).
- Don't drop it too low — around 0.5–1 g per kg is a sensible floor.
Fat is essential — your body cannot make some fats and must get them from food. It builds cell membranes, produces hormones, and carries the fat-soluble vitamins A, D, E, and K. Because it provides 9 calories per gram, more than double protein or carbs, it's energy-dense and easy to over- or under-eat.
On a diet, fat shouldn't be slashed to nothing: very low fat can impair hormone production and nutrient absorption. A practical floor is around 0.5–1 gram per kilogram of bodyweight per day, prioritizing unsaturated sources like olive oil, nuts, and fish, which also supply beneficial omega-3s.
Frequently asked questions
Does eating fat make you fat?
No — excess calories cause fat gain, regardless of source. Fat is calorie-dense so it's easy to overeat, but it isn't uniquely fattening.
How little fat is too little?
Dropping below roughly 0.5 g per kg of bodyweight for long periods can impair hormones and vitamin absorption. Keep fat at a sensible minimum even when cutting.
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