Sounds like insecurity -- either he is mad that there is a part of your life he cannot influence, or that you will lose weight and leave him for another person. Either way, passive agressive whining is the least attractive thing a person can do.
It might be time to sit him down, explain he has no choice in what you do to your body, and that if he can't be supportive, he needs to suck it up and shut up.
Some people are so insecure, that when they cannot control the world around them, they have a temper tantrum and are suddenly reduced to toddlers. The only way to deal with a child is to stick to your guns, firmly, without yelling or negotiating.