The fundamental reason why 2,4-Dinitrophenol (DNP) burns fat is surprisingly complicated. Basically, it intoxicates mitochondria in your cells being their power

The fundamental reason why 2,4-Dinitrophenol (DNP) burns fat is surprisingly complicated. Basically, it intoxicates mitochondria in your cells being their power houses. These organelles create ATP, a universal metabolic energy carrier, by maintaining a proton gradient across its membrane. By means of chemical osmosis this gradient is what drives the ATP synthase enzyme under normal conditions. Now, DNP is capable of shuttling protons along the gradient and short-circuits this process catalyzing the conversion of fatty acids into worthless heat. Interestingly, babies use a controlled variant of this mechanism to help maintain their body temperature thanks to their brown fat tissue. It makes babies look cute and keep warm. :)