Dump him. Change the locks. Leave his stuff out on the lawn. Even if he’s concerned about your health, he’s being a jerk about it. His constant complaining is ruining your self-esteem and not helping. I’m going to guess he isn’t exactly Jake Gyllenhaal in Prince of Persia either. Chances are, he can stand to cut down on the pizza-flavored Doritos and hit the gym every once and a while.
Why do you need someone like him in your life? It’s one thing to support you with life changes and encourage exercise and a healthy diet. Being a little whiny b-word and making snipe-y comments is counterproductive. He’s damaging your self-esteem and not helping you to improve your life.
You don’t need this negativity in your life. Weight loss should be something you do for your health and happiness, not to please your douche-troll boyfriend. I’ve got news for you: even if you lose weight, he’s going to complain. He’s looking for something to be unhappy about. It’s his way of showing he’s not happy in the relationship. Move on. It will be better for both of you. Find someone nice and supportive. Take care of yourself. This guy is a mental drain and a waste of oxygen.