Typically, I hear of situations where folks will lie to make a situation easier for themselves or the other person. However, this situation I see it HARDER to lie than to speak truthfully.
Don't compliment the taste of the food he cooked if you don't like it. Instead, compliment his effort and will to serve.
You don't need to lie and I hope you don't feel like you have to. That would be a sham.
It would be an even bigger shame to hurt his feelings and overall just not worth it. He is an amazing man and I can handle a little sufferage now and then. It is a very small price to pay for all that he does for me.
He doesn't cook as often as I do and usually cooks food I love when he does cook. I am an insanely picky eater and that is not his fault. He makes the most amazing cabbage rolls and shepard's pie
On the other hand, there are times I cook food that he does not like and he does much the same thing I do, eats it, and does not complain. I am (trying) to get better at cooking fish, but I suck at it...royally. He is a trooper and tells me, "not bad," which translates to, "Dear God woman please stop experimenting" LOL
So in the end, what it boils down to is this..
What is more important?
Being 100% honest, which gains no benefits/rewards?
Or keeping the negative comments to yourself and being appreciative that your husband is even willing to cook for you at all?
I prefer to be appreciative for what he does. I don't need to give him a backhanded compliment. Just the compliment.
To me it's like saying, "Not perfect, but it'll do."
"The food sucked, but I appreciate you trying..." Yea, that is a great way to show appreciation.
I once told my husband I liked homemade french fries, but hated cutting them up. So he bought me an attachment for my food processor that cuts french fries for my birthday present. I still haven't used it. There will be NO homemade french fries in my house ever. 
