Fat is the most misunderstood macro. The low-fat 90s taught a generation to fear it; the keto wave taught the next to overdo it. The right answer is in between, and it scales with bodyweight and total calories, not with whatever diet is trending.
The numbers in grams
- Minimum: 0.5 g per kg bodyweight (0.23 g/lb). Below this, hormones and absorption of fat-soluble vitamins suffer.
- Standard: 0.8-1.0 g/kg (0.36-0.45 g/lb). The sweet spot for most people.
- Higher-fat diets: 1.2-1.5 g/kg. Fine if you prefer this style and total calories work out.
For a 75 kg (165 lb) adult that's roughly 60-75 g/day at the standard target. The macro calculator sets it to 25% of total calories by default, which lands in the same range for most people.
Why "% of calories" is the more useful frame
At low total calories (1,400 kcal), 25% fat = 39 g. At high total calories (3,200 kcal), 25% fat = 89 g. The same percentage scales sensibly with diet phase. That's why the calculator and most coaches use the percentage approach.
- Cut: 20-30% of calories from fat
- Maintenance: 25-35%
- Bulk: 20-30% (leaves more room for carbs as training fuel)
What happens if you go too low
Below 0.4 g/kg long term: testosterone and estrogen drop, sex drive falls, skin and hair quality decline, joints feel stiff, you stop absorbing vitamins A, D, E and K properly. Extreme low-fat dieting is one of the silent reasons cuts go wrong.
What happens if you go too high
Above 40% of calories from fat, carbs and sometimes protein get squeezed out. For most people that hurts training output, glycogen, and satiety. If you're keto by choice, fine, track ketones and protein. If you're not, there's no upside.
Quality matters too
- Prioritize: olive oil, avocados, nuts, seeds, fatty fish, eggs, dairy.
- Limit: deep-fried foods, industrial seed oils used in excess, ultra-processed snacks.
- Don't obsess: a tablespoon of butter or coconut oil isn't going to hurt anyone.
Putting it on a plate
70 g fat looks like: 2 tbsp olive oil (28 g) + 1 oz almonds (14 g) + 2 whole eggs (10 g) + 3 oz salmon (10 g) + dairy and incidentals (8 g). Spread across the day, every meal has some fat to slow digestion and keep you satisfied.
Run the macro calculator to set fat alongside protein and carbs in one go, that's the easiest way to make sure the total balance is sane.