For thousands of years, practitioners of traditional Chinese medicine have used glucomannan treat asthma, coughs, and other common health problems. In recent years, the fiber-rich substance (extracted from the root of the konjac plant) has gained popularity as a natural weight loss aid. To date, few studies have looked at whether taking glucomannan as a dietary supplement can help you lose weight. While there's some evidence that glucomannan may promote weight loss by increasing feelings of fullness, it's too soon to recommend glucomannan supplements to people attempting to slim down. Still, it's possible that fiber sources in general may help support weight loss when incorporated into a healthy diet and combined with regular exercise. To boost your fiber intake, turn to foods like flaxseed, oatmeal, and whole grains.