When glucose (or another source of energy) is degraded, it releases protons and energy. Those protons are stored in the inter-membrane space. When those protons go through the internal membrane of mithocondria, they make ATPase work, and so ATPase takes that energy to produce ATP. If anything prevents protons to go through the internal membrane of mithocondria, then they can’t make ATPase work, and that energy will be released as heat. The body will “feel” that it needs more ATP, so it’s like: “oh it seems that I haven’t degraded enough glucose, so let’s degrade more glucose”. And that will make you loose weight.