It's everywhere and we can't escape. That's not the point either. Also having food thoughts is ok, it is when food begins to control you and be an obsession. When your thoughts are always on food and nothing else.... when all yiu think about is calories or macros, recipes, food you can or can't eat, baking food, eating food, buying food. When food is always on your mind in someway, then it's not normal and is often a sign of starvation. The body is so starved and so desperately wants food and so you just think about food as your body is telling you to feed it.
But how much is normal to think about food? Well it depends.... I mean if you are a chef or work with food then you will obviously think about food more than someone who is studying or not working with food.
How much you think about food varies from day to day. Somedays you need to think more about it such as if you are busy all day and you know you need to make lunch boxes and pack snacks. Or for example if I do alot of exercise then I know I need to eat alot and think more about what I eat than days where I just do a normal workout. But also if I'm baking or food shopping or making meal boxes for the week then I need to think about food, but that is planning and not an obsessive thinking about food.
If you are free from obsessive food thoughts you will know the difference. Do the thoughts control you? Can you think of other things and focus on other things rather than just food? Do you have other hobbies in life than just food related ones? Can you eat meals with picturing them or writing them down.... do you spend all day thinking about your next meal or planning what you are going to eat right down to the detail, if it is not necessary? Because sometimes you do need to plan your days and what food you will eat, for example when you have time to eat, what you can eat etc but if it's just an everyday thing where you need to plan precisely, when you could infact use that time and energy on other things and not just on food.
So food thoughts are also part of a normal life and healthy thoughts but they are more in the sense of planning and the thoughts aren't controlling and don't take up the whole day. A person doesn't just yhink about food and might just think about food or what to eat when they are craving it, rather than thinking on Friday evening I will eat this and on Saturday evening I will eat that.
Usually you know yourself whether the thoughts are controlling or just random food thoughts.