Perhaps surprisingly, it isn't particularly difficult to circumvent a Pokémons metabolism willingly - with natural instincts always favouring a plentiful food source, most pverfed pokemon like this fennekin subject will in fact wear their low hanging guts with a semblance of pride, instead of disgust! This of course, is to be encouraged at all opportunities, a positive attitude will only reinforce your 'mons association of gaining being good!
It shan't be long before your own darling can be strutting about, showing off their stuff not with shame, but pride, confident in the belief that their gut is simply built to stick to the floor, brushing sensitively across every surface it traverses!