Beans might have a reputation as "the magical fruit" for less-than-savory reasons, but they're actually a nourishing addition to your healthy diet. Beans come loaded with essential minerals like magnesium and potassium, as well as vitamins like folate. Beans also have several properties that make them beneficial for weight loss, so including beans in your diet can help you drop pounds, as well as boost your overall health.
Nutrients From Eating Beans
Beans are packed with beneficial nutrients, including protein and fiber -- a one-two punch for weight loss. Simply eating more fiber -- 30 grams per day -- helps with weight loss, even if you aren't sticking to a strict diet, according to an Annals of Internal Medicine study published February 2015. And protein also helps you shed pounds. It boosts satiety -- so you feel more satisfied after a high-protein meal -- and it's relatively hard to break down, so you burn more calories during digestion.
The specific amount of protein and fiber you'll get per serving depends on which type of bean you choose. A cup of boiled soybeans, for example, has 31 grams of protein and 10 grams of fiber. A 1-cup serving of boiled black beans has 15 grams each of fiber and protein, while an equivalent serving of canned kidney beans has 13 grams of protein and 11 grams of fiber.
Choose Low Glycemic Foods to Lose Weight
Beans have a low glycemic index, which makes them beneficial for weight loss. The glycemic index, or GI, is a measure of how foods impact your blood sugar -- foods that have a subtle, sustained effect on blood sugar have a low GI, while foods that trigger blood sugar spikes have a high GI. When you eat a high-GI food, that spike in blood sugar triggers the rapid release of a hormone, called insulin, that lowers your blood sugar again. Because this all happens so fast, the rush of insulin actually causes a blood sugar crash, which leaves you feeling hungry.
If you want to lose weight, sticking to a low-GI diet can help -- it'll keep you fuller longer and help you eat less later in the day than high-GI foods, according to the Linus Pauling Institute.You won't experience those dramatic blood sugar changes that trigger hunger.
Beans fall significantly under the cutoff for a low GI, which is 55. For example, soybeans have a GI of 15, chickpeas have a GI of 10, and black beans, kidney leans and lentils all have a GI under 30. Even baked beans -- which sometimes contain added sugar, like maple syrup -- have an average GI of 40.
Evidence for Beans and Weight Loss
There's some research linking beans to weight loss -- as well as improved health as you lose weight. One review, published in Obesity Research in 2014, reports that using legumes in place of meat can help you shed pounds. The review also found that small changes like eating more beans might be very effective for weight loss since they're easy to stick to over time. Another study, published in the Canadian Journal of Dietetic Practice and Research in 2015, found that eating canned navy beans has weight-loss benefits. The researchers studied overweight women and men who ate 5 cups of canned navy beans weekly and found that they reduced their waist size over the course of four weeks. The men and women who ate beans also experienced other benefits, including lower cholesterol levels -- as well as lower levels of the harmful cholesterol linked to heart disease. While these studies don't necessarily mean that beans are your magic bullet for weight loss, they do show that it's beneficial to include beans in your weight-loss diet.
Serving Beans in a Weight-Loss Diet
Keep canned beans on hand for convenient, weight-loss-friendly meals. Use hummus in place of mayo on your sandwiches, add a handful of black or kidney beans to vegetable soups or top your salads with a serving of chickpeas.
You might get extra benefits by pairing your beans with whole grains, according to a 2014 study published in the Journal of Agricultural and Food Chemistry. The study authors found that the nutrients in grains and beans seem to work synergistically, and eating both foods can lower your chronic disease risk more than eating one or the other. Try mixing brown rice and black beans with vegetables or serving bean chili with whole-grain toast to combine beans and grains.
- Linus Pauling Institute: Legumes
- Harvard Health Publications: Extra Protein Is a Decent Dietary Choice, But Don’t Overdo It
- Annals of Internal Medicine: Single-Component Versus Multicomponent Dietary Goals for the Metabolic Syndrome
- Linus Pauling Institute: Glycemic Index and Glycemic Load
- Harvard Health Publications: Glycemic Index and Glycemic Load for 100+ Foods
- Canadian Journal of Dietetic Practice and Research: Canned Navy Bean Consumption Reduces Metabolic Risk Factors Associated With Obesity
- Obesity Reviews: A Review of the Nutritional Value of Legumes and Their Effects on Obesity and its Related Co-Morbidities
- Journal of Agricultural and Food Chemistry: Whole Grains and Pulses: A Comparison of the Nutritional and Health Benefits
- USDA National Nutrient Database: Nutrient Lists