I looked it up and it appears there were 2 studies, both in Cameroon in the past 4 years. Both studies were extremely small which really means that further study is required. It appears that it is high in fiber, which can help make you feel full and contains some vitamins. Although I see recommendations that you shouldn't take it for more than 4 weeks at a time, it doesn't necessarily look harmful but then again, caution is always recommended.
You can't out-exercise poor eating habits.