Potato vs White rice: nutrition per 100 g

IFCT 2017 lists potato as the fresh tuber and rice as raw, dry grain. Potato holds 80.7 g of water per 100 g; raw rice holds 9.9 g, about 8.2 times less. So 100 g of dry rice is a concentrated food with 356 kcal and 78.2 g of carbohydrate, while 100 g of fresh potato has 70 kcal and 14.9 g. Once rice is boiled, it soaks up water and its energy per 100 g of cooked rice falls a long way, closer to boiled potato. The fair comparison is the plate you actually eat, not the raw weights.

Both are starchy staples. Raw rice ranks 2nd of 256 foods for carbohydrate; potato is a moderate source because of its water. Rice has more protein, 7.9 g per 100 g dry against 1.5 g in fresh potato, covering 15 per cent of a man's daily need. Fibre is low in both: 2.8 g in rice and 1.7 g in potato, which ranks last of 10 roots and tubers. Neither is a fibre food, so dal, vegetables and salad need to share the plate. Nutritionally, potato behaves more like a staple grain than a green vegetable, which is worth remembering when an aloo sabzi is counted as the meal's vegetable.

Potato has 541 mg of potassium per 100 g, about 5.0 times the 108 mg in raw rice, ranking 2nd of 10 roots and tubers. Potassium helps the body balance sodium and maintain normal blood pressure. Potato also supplies 23.2 mg of vitamin C, covering 29 per cent of a man's daily need, while IFCT lists none for rice. Folate is 16 micrograms against 9, and magnesium 24 mg against 19 mg. Boiling potatoes in their skins and not overcooking them keeps more of the vitamin C.

Rice leads on zinc, 1.21 mg per 100 g dry against 0.28 mg, about 4.3 times as much, and on phosphorus, niacin and riboflavin. Iron is low in both, 0.65 mg and 0.57 mg. In many Indian homes the two are eaten together rather than instead of each other: aloo posto with bhaat in Bengal, aloo bhujia with rice in Bihar, aloo fry with sambar rice in the south, and potato in biryani in Kolkata. In such meals, the total amount of starch is what deserves attention.