Onion

Most onion cultivars are about 89% water, 4% sugar, 1% protein, 2% fibre and 0.1% fat. They contain vitamin C, vitamin B6, folic acid and numerous other nutrients in small amounts. They are low in fats and in sodium, and with an energy value of 166kJ (40 kcal) per 100 g (3.5 oz) serving, they can contribute their flavour to savoury dishes without raising caloric content appreciably.

Onions contain chemical compounds such as phenolics and flavonoids that basic research shows to have potential anti-inflammatory, anti-cholesterol, anticancer and antioxidant properties.[medical citation needed] These include quercetin and its glycosides quercetin 3,4'-diglucoside and quercetin-4'-glucoside. There are considerable differences between different varieties in potential antioxidant content. Shallots have the highest level, six times the amount found in Vidalia onions, the variety with the smallest amount.

Nutrition Facts
OnionsOnions, cookedOnions, sweetOnions, yellow, sauteedScallion, Welsh onionOnions
Amount Per 1 slice, thin (9 g)1 tbsp chopped (10 g)1 slice, medium (1/8" thick) (14 g)1 slice, large (1/4" thick) (38 g)10 rings (60 g)1 small (70 g)100 grams1 medium (2-1/2" dia) (110 g)1 cup, sliced (115 g)1 large (150 g)1 cup, chopped (160 g)1 medium (2-1/2" dia) (110 g)

Calories 44
% Daily Value*
Total Fat 0.1 g	0%
Saturated fat 0 g	0%
Polyunsaturated fat 0 g
Monounsaturated fat 0 g
Cholesterol 0 mg	0%
Sodium 4 mg	0%
Potassium 161 mg	4%
Total Carbohydrate 10 g	3%
Dietary fiber 1.9 g	7%
Sugar 4.7 g
Protein 1.2 g	2%
Vitamin A	0%	Vitamin C	13%
Calcium	2%	Iron	1%
Vitamin D	0%	Vitamin B-6	5%
Vitamin B-12	0%	Magnesium	2%
*Percent Daily Values are based on a 2,000 calorie diet. Your daily values may be higher or lower depending on your calorie needs.

Sources include: USDA