I find it really interesting how many responses revolve around husband being a saboteur, insecure, disprespectful, etc, etc. And I know people are joking, but it's also interesting how lightly the threat of violence or punishment (ie, witholding sex) is offered.
I don't mean to sound sanctimonious, but relationships aren't quid pro quo. And certainly they shouldn't be based on the idea that if someone does something that doesn't further your own goals, you should "get back at them" in someway.
Can we maybe look at this as two people with their own complexities and baggage and history and conditioning, instead of assuming that one is out to get the other? Sometimes, we do things, and other people do things, and they are related only in so much as they are about the same thing but aren't actually about disrespect.
I can imagine too, that there are things you do that frustrate him and yet you keep doing it anyway because it's habitual (or really, not a problem for you?). Behavior is a really complex thing.
The bigger issue I think is that you are serious about 5:2 and your husband doesn't seem to understand your seriousness. I would suggest finding a time (not when there is food around or you are fasting or anything) and sitting him down and saying, "Hubby, I feel very strongly about this way of life and sometimes I think you don't understand how serious I am about it. It would mean a lot to me if you could be a little more supportive of it. What can we do to make that happen?"

And if he responds by totally dismissing your concerns, then stab him with a fork.