processed foods are easy to make appetizing.
you basically just need to remove fiber and add sugar, salt, carbs, fats, MSG, some flavoring and maybe a few narcotic-like substances like Cheese or drugs like Caffeine or Cocoa.
science has found the most irresistible foods are the ones that mix fat with carbs - pizza, donuts, potato chips, ice cream etc - they all fall into this category.
what is notable is such foods are almost nonexistent in real world. as most fruits and vegetables lack fat and most animal foods lack carbs.
the few exceptions like nuts are seasonal and are well known to be the foods that break people's diets.
one dude i used to speak to on Twitter was trying to make this observation into a diet but it didn't catch on, and besides pretty much all other diets are in effect already exploiting this. as whether you're on a low fat or low carb diet you're eliminating these Fat+Carb combos.
anyway appetizing foods is how you get fat. bland is what you actually want for weight loss.