I don't know where you've got the idea bread is unhealthy from! But it's bonkers!
As for dh's influence on you - you could have an influence on him or just make a decision not to be influenced by him. You're an adult you don't have to have what he does!
Truly there are no bad foods only bad diets. Almost all food has nutritional value.
Even chocolate has calcium, iron, protein.
Crisps vitamins and minerals.
A healthy, balanced diet includes all food groups in the right proportions.
Why on earth would you no longer be compatible if you were slim?! You'd still be the same personality! Or is that a not so subtle way of saying you think you've settled for dh and could do better? 🤔
It's actually not that hard to "tweak" meals to suit you both. I'm veggie and dd and exh are not. They're also both quite fussy in different ways - exh by far the worst in this. I eat a far wider variety of items than the 2 of them together!
I've been "tweaking" for over 20 years as a result.
Eg if you're having chicken breast and salad, he has chips and peas with his chicken, you make a casserole he has 2/3 you have 1/3 and he has extra carbs of whatever form, if you're having spag Bol you have less pasta maybe no cheese on top, he has extra pasta, larger portion of mince and cheese on top.