Last year, two nieces of mine drank a particular brand of coffee ( i forgot the name. ) which is marketed as a coffee to get you slim. It was effective for them. But when they stopped taking it after a few months, they got back their lost weight so fast that they are now a little heavier before they started to drink that coffee. And based on their stories, they experienced migraines and headache that's why they stopped drinking it. Based on this, It is still best to exercise and eat proper diet continuously in losing weight.