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Onion Slice Calories
Fresh, low-calorie, source of vitamin C
CALORIES
GI
POTASSIUM
FIBER
Onion Slice Nutrition Facts
Selected: 100 g
40
KCAL / 100G
Carbs
9.3g
· 88%
Protein
1.1g
· 10%
Fat
0.1g
· 2%
Fiber
1.7g
Onion Slice Vitamins & Minerals
Vitamins
Vitamin C
7.4mg · 8% DV
B6
0.12mg · 7% DV
Folate
19µg · 5% DV
B1
0.05mg · 4% DV
Minerals
Phosphorus
29mg · 4% DV
Potassium ⭐
146mg · 4% DV
Calcium
23mg · 2% DV
Magnesium
10mg · 2% DV
Onion Slice Glycemic Index
GLYCEMIC INDEX
GLYCEMIC LOAD
Accounts for portion size — a more realistic measure than GI alone.
Is Onion Slice 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 Onion Slice Contain Allergens?
No known major allergens
Which Diets Is Onion Slice Good For?
Vegan
✓ Suitable
Vegetarian
✓ Suitable
Gluten-Free
✓ Suitable
Dairy-Free
— Not suitable
Mediterranean
✓ Suitable
Paleo
✓ Suitable
Whole30
— Not suitable
DASH
— Not suitable
Keto
— Not suitable
Low FODMAP
— Not suitable
Onion Slice Fat Profile
SATURATED
0.03g
MONOUNSATURATED
0.01g
POLYUNSATURATED
0.02g
Omega 6:3 ratio 2:1
Below the ideal 4:1 — a good omega balance.
Foods Similar to Onion Slice
Onion Slice — Frequently Asked Questions
How can sliced onion be cooked without turning bitter?
Cook it slowly over medium-low heat with a little oil or water. Very high heat can scorch the onion and create a bitter flavor; a small pinch of salt helps it release moisture.
How long does sliced onion keep in the refrigerator?
Store it in an airtight container in the refrigerator for up to about 7 days. Keep it tightly sealed so its odor does not transfer to other foods.
Can sliced onion be frozen?
Yes, sliced onion freezes well. It becomes softer after thawing, so it is best used in soups, sauces, omelets, and cooked dishes rather than fresh salads.
Is raw onion or cooked onion the better choice?
Both can fit into a healthy diet. Raw onion has a sharper flavor, while cooking makes it sweeter and may make it easier for some people to digest.
Do you need to add sugar to caramelize onions?
No. Onions develop a naturally sweet, browned flavor when cooked slowly over low heat; added sugar may speed up browning but is not necessary.
What foods pair well with sliced onion?
It pairs well with eggs, legumes, yogurt-based dishes, meat or plant proteins, tomatoes, and mushrooms. Lemon juice or vinegar can balance its sharp flavor in salads and side dishes.
Does onion cause bad breath?
Yes, especially raw onion, because it contains sulfur compounds that can temporarily affect breath. Drinking water, brushing your teeth, and eating fresh herbs such as parsley may help reduce the odor.
Does onion cause bloating for everyone?
No, but it can trigger gas or bloating in some people, particularly those with irritable bowel syndrome or FODMAP sensitivity. Smaller portions, thoroughly cooked onion, or the green tops of spring onions may be better tolerated.
Can onion cure a cold?
No, onion is not a cure for the common cold. It can be part of a nourishing diet, but rest, fluids, and medical advice when needed remain important for managing illness.
Is onion better before or after a workout?
Onion is not usually a stand-alone workout fuel, but it can be included in a post-workout meal with eggs, yogurt, legumes, or another protein source. People with a sensitive stomach may prefer to avoid raw onion before exercise.
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Nutrition data compiled from USDA FoodData Central and scientific sources.