Pretty sure caffeine speeds up the Central Nervous System, increases fat metabolism by initiating the release of Free Fatty Acids, and reduces carbohydrate oxidation oxidation during exercise...delaying the onset of fatigue and exhaustion. So if these things happen when caffeine is ingested, how...
How about getting off your butt and going for a walk up an incline, or jogging, or running even (probably can't do that because you are too heavy)