🧅
Red Onion Calories
Antioxidants, low calorie, fiber source
CALORIES
GI
POTASSIUM
FIBER
Red Onion Nutrition Facts
Selected: 100 g
40
KCAL / 100G
Carbs
9.3g
· 88%
Protein
1.1g
· 10%
Fat
0.1g
· 2%
Fiber
1.7g
Red Onion Vitamins & Minerals
Vitamins
Vitamin C
7.4mg · 8% DV
B6
0.12mg · 7% DV
Folate
19µg · 5% DV
B1
0.04mg · 3% DV
Minerals
Phosphorus
29mg · 4% DV
Potassium ⭐
146mg · 4% DV
Calcium
23mg · 2% DV
Magnesium
10mg · 2% DV
Red Onion Glycemic Index
GLYCEMIC INDEX
GLYCEMIC LOAD
Accounts for portion size — a more realistic measure than GI alone.
Is Red Onion Processed?
NOVA 1
Unprocessed
1. Unprocessed
2. Minimally Processed
3. Processed
4. Ultra-Processed
NOVA classifies foods into 4 groups by industrial processing. NOVA 1 (unprocessed) is the healthiest.
Does Red Onion Contain Allergens?
No known major allergens
Which Diets Is Red Onion Good For?
Vegan
✓ Suitable
Vegetarian
✓ Suitable
Gluten-Free
✓ Suitable
Dairy-Free
— Not suitable
Mediterranean
✓ Suitable
Paleo
✓ Suitable
Whole30
— Not suitable
DASH
— Not suitable
Keto
✓ Suitable
Low FODMAP
— Not suitable
Red Onion Fat Profile
SATURATED
0.02g
MONOUNSATURATED
0.01g
POLYUNSATURATED
0.03g
Omega 6:3 ratio 2:1
Below the ideal 4:1 — a good omega balance.
Foods Similar to Red Onion
Red Onion — Frequently Asked Questions
How many calories are in red onion, and is it diet-friendly?
Red onion has 40 calories per 100g. As an unprocessed vegetable, it fits many eating patterns including vegetarian, vegan, Mediterranean, paleo, keto, pescatarian, flexitarian, and gluten-free diets.
Does red onion have a high glycemic index?
No, red onion has a glycemic index of 15, which is considered low. Per 100g, it provides 9.3g carbs and 1.7g fiber.
Have another question about Red Onion?
Ask the AI nutrition coach — calories, portions, alternatives and more, answered in seconds in the app.
Scan calories with your camera
Instant AI nutrition analysis
Nutrition data compiled from USDA FoodData Central and scientific sources.