It's also very variable on the individual level and you have to know your body. For example if I eat even a little in the morning it's impossible for me to fast

It's also very variable on the individual level and you have to know your body. For example if I eat even a little in the morning it's impossible for me to fast and I'll be hungry mad by midday. But if I only drink coffee and have a lot of work to do the day can pass smoothly without feeling hungry. Also dependent on the type of food for me, food dense in proteins and fats can feed me for the day, while with carbs I'll be hungry a few hours after.