Wouldn’t say there are complete no nos (except for sodas/soft drinks except soda water or tonic water fir my gin 😁) though there are things I avoid or eat rarely. I don’t eat bread, rice or pasta as they tend to sit heavily & are simple carbs. Apart from fruit & vegetables, I eat 2 serves of multi or whole grain carbs a day (multi grain crackers & rolled oats). Potatoes tend to sit heavily too especially mashed, baked/roasted aren’t as bad but I rarely have them.
I rarely eat sweet things like cakes, desserts, chocolates, etc. except on special occasions. Like I have dessert at Christmas & may have a small piece of cake or dessert at a special event like a wedding (couple of times a year). Generally avoid foods with artificial sweeteners or sugar substitutes & I know those that do like my yoghurt & protein bar. My added sugar intake is less than 10g a day usually only about 5g.
I don’t use pre prepared sauces except Asian ones like hoi sin, oyster, etc. & gravox.
I still enjoy a drink every now & again just not every night like I used to & one glass is usually enough.
I prep & cook most of what I eat myself to keep my foods primarily no or low processed.
I used to enjoy a dessert when I went out or something sweet like a biscuit or cup cake after dinner & 4 or 5 meals a week were rice or pasta & ate bread every day before surgery but I really don’t miss them now & I think I’m better without them. Sometimes it would be a little easier when I go out but there are always alternatives or work arounds. Mind you it’s harder to avoid chilli or heavily spiced foods (have a sensitivity to them) when I go out than avoid pasta, rice & bread.
This is what I learnt worked for me. Your way of eating in maintenance may be different to mine and that’s okay. It just has to work for you. As I said you have to be flexible, you can’t control every thing every day. And you have to accept that sometimes you might go off piste & that’s okay.