I'm going to give you the number one secret to optimal fat loss; it is cutting calories. That's it. If you don't get that part right, it's pretty damn near impossible to lose body fat.
But companies and "experts" are still going to talk to you about raising your metabolic rate and speeding up the fat-burning process, through supplements and special diets, but these are false promises.
Based on what we know about the human body and existing research, you cannot hack your metabolism; it is largely determined by your body weight (mainly lean mass) and basal metabolic rate (BMR). And even though some supplements like caffeine, might cause minor increases in BMR, the amount is typically so small it doesn't outweigh the need for calorie control (3).
Fat-burning supplements are often dangerous, ineffective, and expensive.
That's because a majority of them work one of a few ways - increasing your body temperature or your heart rate, in the hopes of helping you burn more calories, or improving fat oxidation - although calorie control is still needed to lose body fat overall (4,5).
Research has yet to conclude that any supplements promote more fat loss than diet alone. The bottom line, if something sounds too good to be true, it probably is.