drink 8 10 ounce glasses of water (minimum) and stop all the sugar. pick mild foods and eat them alone and see if your body odor changes (white rice, chiccken breast/turkey beast with mild seasoning like hot sauce, no garlc onion strong spices etc) in a while see if your smell changes. use something to increase you bowel movements with some kind of exlax. if no change get your kidneys and liver checked at a doctor and tell them about it.
you could try body powder or baby powder to kil some of the sweat stench but in the end if the sweat is bbad smelling it will come out anyway
usually its coming from your sweat which is more than likely an internal issue with diet, hormones, gastrointestinal or liver kidney issue