Believe it or not, nagging is highly inefficient at motivating men. It just makes us hate you, wanting to spend less time with you and retract emotionally. If you love and respect someone you don't treat him like a kid, which is what nagging is. Try preparing only healthy food, saying you are not attracted anymore and restrict sex, even permanently (it's important not to just restrict sex but openly tell him why before doing it). We men tend to react better to direct and basic behaviour.