17yr old male thanks You losein kitchen. Diet. There's no such thing as "spot reduction." In other words, you have no say in where you store or lose body. That's solely down to genetics Diet is 90% of the work. Lower your calorie intake. The moreyou lose, the more you'll see an improvement on your belly and chest. So basically you loose weight if youless calories than you need and you can't control where you loose the weight at all However if your pretty thin and only have a slight bigger or not flat belly, some abs can definitely help, tiding everything up and will make your belly look more flat even though theis still there.