Research suggests these magical pulses are one of the closest things we have to a fat-burning pill. For starters, beans are a great source of resistant starch, a type of slow-digesting, insoluble fiber that feeds the healthy bacteria in your gut, triggering the production of the chemical butyrate, which encourages the body to burn fat as fuel and reduces fat-causing inflammation. They're also one of the top sources of soluble fiber. A recent study by Wake Forest Baptist Medical Center researchers found that for every additional 10 grams of soluble fiber eaten per day, a study subject's belly fat was reduced by 3.7 percent over five years. Black beans? One cup boasts an impressive 4.8 grams of soluble fiber.
Caffeine is often included in fat-burning supplements the form of yerba mate or guarana — however, manufacturers may include these substances in amounts they’re rarely used otherwise. Caffeine is a common weight loss ingredient because it often has the effect of dulling someone’s appetite and help increase energy for activity. However, too much caffeine can cause side effects like jitteriness, headaches, insomnia, anxiety, heart palpitations, diarrhea and more.