Rajma glycemic index and load: kidney beans GI explained

The rajma glycemic index used across this site is 45, and it comes from two India-tested entries in the University of Sydney's international GI database. A 1981 study tested boiled rajmah on 6 subjects and recorded a GI of 19; a 1991 study tested kidney beans that had been dried, soaked for 12 hours, stored moist for 24 hours and steamed for an hour, on 12 to 15 subjects, and recorded a GI of 70. The database lists the mean of the two as 45.

The about-GI page of the University of Sydney describes the GI as a ranking of carbohydrates on a scale from 1 to 100 according to the extent to which they raise blood sugar levels after eating. The page's bands put low GI at 55 or less and high GI at 70 or more, so the boiled test sits deep in the low band while the steamed test sits exactly at the high-band line.

Per 100 g, raw rajma (red kidney beans) carries 48.6 g of carbohydrate, 16.6 g of fibre, 19.9 g of protein and 300 kcal (IFCT 2017). Fibre is part of the picture: the Dietary Guidelines for Indians note that dietary fibre delays and retards absorption of carbohydrates and fats and increases the satiety value. The table below sets rajma beside two other common dals; the numbers are per 100 g of the raw food, so a cooked portion weighs more than its dry measure.

Per 100 g raw, edible portion. Composition: IFCT 2017 (ICMR-NIN). GI: University of Sydney GI database. — means not reported. These are average values for the food; the label on a pack gives the values for that product.

Glycemic load (GL) scales the GI to the amount of carbohydrate actually eaten: multiply the food's GI by the grams of available carbohydrate in the portion and divide by 100, where available carbohydrate is total carbohydrate minus fibre. For rajma that gives two useful figures. A katori cooked from 30 g of dry beans carries about 14.6 g of carbohydrate and 5 g of fibre, leaving about 9.6 g available; 45 x 9.6 divided by 100 gives a GL of about 4.3. A fuller plate cooked from 50 g dry carries about 24.3 g of carbohydrate and 8.3 g of fibre, leaving about 16.0 g available, and its GL comes to about 7.2.

The GI stays 45 either way; the GL grows because the portion grows.

The two India-tested entries are a plain boiled test and a soaked, steamed test. Neither came from a pressure cooker, and none of the entries listed for rajma is for canned beans, so 45 cannot be read as a cooker-tested or a can-tested figure. The rajma recipes on this site are pressure-cooked, following the soak and cook steps on how to soak rajma and how to cook rajma, so read 45 as the closest reference point the database offers. There is also no tested GI for rajma curry or a rajma chawal plate as dishes: the database entries are for plain cooked beans, so 45 belongs to the bean, not to a finished plate.

The kidney beans glycemic index, 45, sits above the other pulses in the table. Cowpea (lobia) averages a GI of 37 across 10 entries ranging from 7 to 58, none of them India-tested; bengal gram dal (chana dal) carries a single India-tested GI of 11, from the same 1981 study that tested the boiled rajmah; whole wheat (sharbati) has two India-tested entries, 63 in that same 1981 study and 30 in the 1991 one. The 2021 international tables of GI and GL values reach the same shape: legumes were usually low-GI foods, at 55 or below on the 100-point glucose scale, with consistent values around the world. Rajma's own spread, 19 to 70, is the reminder that the preparation line matters as much as the food line.

The GI is one number in a three-part decision: portion, pairing and preparation. A katori of cooked rajma from 30 g dry lands near 90 kcal and 14.6 g of carbohydrate; a 50 g dry serving lands near 150 kcal and 24.3 g of carbohydrate, so the portion sets how much carbohydrate arrives, not the GI alone. The is rajma good for diabetes page walks through the swaps, and the rajma recipe roundup lists the dishes, from rajma chawal to curry and khichdi. Whatever you cook, the bean's own numbers stay as above; the rest of the plate decides the meal. Everything else about rajma, from types to storage, starts at the rajma beans hub.

Under the international standard method the about-GI page describes, a GI value is determined by feeding 10 or more healthy people a portion of the test food containing 50 g of available carbohydrate and measuring their two-hour blood glucose response, which is then compared with the same people's response to glucose. Two rajma entries tested in India landed 51 points apart: the boiled test scored 19 and the soaked-and-steamed test scored 70. The database lists both, and 45, their mean, is the rajma GI quoted across this site. Boiled beans tested outside India span 9 to 51 across 11 entries with a mean of 30.

What is the glycemic index of rajma?

The rajma glycemic index used on this site is 45, the mean of the two India-tested entries in the University of Sydney GI database: boiled rajmah scored 19 in 1981 and beans soaked 12 hours, stored moist a day and steamed scored 70 in 1991. Low GI runs 55 or less and high GI starts at 70, so the two tests land on opposite edges of the scale. GI is a per-food rating, never a per-100-g number.

What is the glycemic load of rajma?

Glycemic load multiplies the GI by the available carbohydrate in the portion and divides by 100, so it grows with the amount eaten. A katori cooked from 30 g dry rajma, with about 9.6 g of available carbohydrate, carries a load of about 4.3; a 50 g dry serving, with about 16.0 g, carries about 7.2. The full arithmetic is in the glycemic load section above.

Does rajma raise blood sugar quickly?

Rajma's GI is 45, in the low band (the mean of two tests, 19 and 70), and the Dietary Guidelines for Indians note that dietary fibre delays and retards the absorption of carbohydrates and fats from food. A katori cooked from 30 g dry still brings about 14.6 g of carbohydrate, so the portion and the plate shape the rise. If you manage diabetes, ask your doctor or dietitian how much rajma suits you; see is rajma good for diabetes.

How much protein in rajma?

The raw bean holds 19.9 g of protein per 100 g (IFCT 2017). Cooked, a katori from 30 g dry carries about 6 g and a plate from 50 g dry about 10 g. Rajma pairs well with a cereal because, as ICMR-NIN puts it, cereals, millets and pulses complement each other to give good quality protein, and rajma chawal is exactly that pairing on a plate.

Can kidney beans cause gas?

They can: the pulse sugars called galacto-oligosaccharides, raffinose among them, pass through the small intestine undigested and get fermented in the colon, releasing gas, though whether that is the primary source of the gas has recently been questioned. Most people who notice gas at first settle down within a few weeks, provided the pulses stay on the menu. Gas or discomfort that keeps coming back is worth a word with your doctor or dietitian.

What is rajma?

Rajma is the red kidney bean, the dried seed of the common bean plant (Phaseolus vulgaris). Indian kitchens turn it into a spiced curry, served over rice as the rajma chawal plate. Raw, the bean gives roughly 300 kcal per 100 g, plus 19.9 g of protein and 16.6 g of fibre (IFCT 2017).