Grapefruit
One of the lowest-GI fruits; the fiber and acidity give it a gentle glucose response and a low glycemic load.
FatTonic Facts
Grapefruit · per serving 1/2 medium (120g)
Excellent · strongly supports fat-burning
| Factor | Amount | Points |
|---|---|---|
| Start | 100.0 | |
| Glycemic load | 3 | −6.6 |
| Sugar (g) | 8 | −6.4 |
| Processing | whole | 0.0 |
| Fiber (g) | 2 | +3.2 |
| Protein (g) | 1 | +0.7 |
| Glycemic index | no published test found | |
| Carbs (g) | 13 | |
| Fat (g) | 0 |
Score model v1
Nutrients: USDA FoodData Central, record 174673 (Grapefruit, raw, pink and red, all areas), public domain, checked 2 Oct 2026.
Glycemic index: no published test found. Searched 28 Oct 2026 in Atkinson et al., International Tables of Glycemic Index and Glycemic Load Values: 2008: Table A1 tests only canned grapefruit segments (no. 986); FatTonic's record is raw grapefruit. The score still uses 25, a value with no recorded source, until a test is found.
Per 100 g (USDA record; serving 120 g): carbs 10.7, sugar 6.9, fiber 1.6, protein 0.8, fat 0.1 g.
What this means for fat-burning
Why this score: glycemic load 3 set it, −6.6 points. Source: USDA FoodData Central, FDC 174673.
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Among the 200 rated foods
Grapefruit scores 91, rated Excellent. It scores higher than 66% of the 200 rated foods.
Rated foods per band: Avoid 0–19: 11; Poor 20–39: 23; Moderate 40–59: 34; Good 60–79: 45; Excellent 80–100: 87.
Frequently asked questions
Does grapefruit spike insulin?
Glycemic load 3 for 1/2 medium (120g); FatTonic Score 91/100 — it strongly supports fat-burning.
Is grapefruit good for fat loss?
Excellent (91/100): grapefruit strongly supports fat-burning.