Fat Burning Stack. The fat attack stack is the combined fat burning effects of using the xpedite® and aerobitine® products together. Caffeine is an alkaline, organic substance (specifically a methylxanthine) found abundantly in coffee beans, coca, tea leaves, and other foods/plants. A great product, utilizes an interesting liquid capsule approach and effective combination of ingredients! Being a supplement expert and an industry expert for almost 20 years, i know who makes the best fat loss ingredients. Sale $89.95 regular price $110.00 tax included. One of the starting blocks of a fat loss stack is the fat burner. Yes bold claim i know, but not one single company has put together the fat burning stacks that i have put together.