Many people do not have nervous hunger problems until they go on a diet : of course, you will tell me, if you are on a diet you eat less, so you get hungry because in general you are used to eating more. This is indeed true, but it is not the only aspect to consider , for two reasons.
The first is that thanks to a strategy known as the volumetric diet, foods that are less dense in calories but also very bulky such as vegetables can replace some of the foods that are dense in calories.
And this strategy is somewhat typical of many low calorie diets.

I’ll give an example with a plate of pasta: if we eat 60 from 120 grams and add no more spoonful of sauce but 350 grams of cauliflower, I can reduce calories and still get a satisfying dish. And light foods? A skimmed dairy product will be slightly less satisfying than a whole one (and undoubtedly less digestible or nutritious): however, light yogurt and light cheeses are widely used by dieters, and the volume of food is the same.
In ketogenic diets, on the other hand, or low carb, it is the massive presence of either proteins or fats that favors the sense of satiety : yet many people have experienced the sense of hunger even during these diets, especially when the ketogenic diet had to work need a low calorie ceiling, almost like a balanced diet.

So the sense of hunger triggered by diets is not a question of greater food shortages or it is not just this. Here are two important reasons why your appetite is triggered: both have to do with adipose tissue.