I do think that body smell has much to do with the diet. Personnally, when travelling the backpacker way, my own odor changes after a few weeks on local low-meat/high-cheese diet. My sweat changes its usual smell to a sour smell, like old yogurt. It disturbs me until I get back to my usual high-meat diet. My traveller friends do not notice this and laugh at my ‘nosal illusions’.