Black beans are rich in both soluble and insoluble fiber. It is also a very good source of magnesium, manganese, thiamin, iron and potassium. Black beans also have phytonutrients especially the coating has polyphenols. When it comes to carbohydrates content, Black beans are akin to legumes which contain slowly digesting carbohydrates. Black beans contain resistant starch that slowly gets converted into glucose. This starch does not get absorbed into the small intestine. When you take more of slowly digesting carbohydrates like legumes they are absorbed into the blood stream slowly thus controlling diabetes.
Even weight loss programs like Nutrisystem and Medifast recommend diet meals that are low in carbs and calories. Nutrisystem provides black beans and rice as one of their diet meals which contains about 210 calories. To burn this amount of calories you will have to walk about 55 minutes. Medifast also recommends its dieters to include lots of fresh fruits and vegetables in to their daily diet. Check http://jane-seymour.com/ to go through a comparison review on the two diet planners.
The glycemic index of black beans totally depends on how you prepare it. If you boil the black beans after soaking it for some time, the glycemic index is low measuring up to 25. When you pressure cook the black beans or use canned beans, the glycemic value ranges from 45 to 65 which is moderate. The full glycemic load is evaluated taking glycemic index and the serving size into account. Half a cup of cooked beans offers about a glycemic load of 7 which is low.
Besides, the black beans contain a very little fat and majority of its fat is polyunsaturated. Half a cup of black beans contain 90 mgms of omega-3 fatty acid and 108 mgms of omega-6 fatty acid. The same serving contains about 7 grams of protein. If you are on low carb diet, you can still eat black beans but pay attention to the portions.