@hungryhungryhortence Eating compulsively all day long, the way you describe it, sounds like it could be addictive behavior or disordered eating. The way you’ve described the problem, it doesn’t sound like just offering useful advice on how to keep from being hungry might not be enough – it seems like your friend may be eating as a way to escape from problems or deal with stress. Perhaps your friend might benefit from seeing a counselor or therapist.
In answer to your question, for me it really depends on the kind of hunger. If you pay attention to your body for a while, you’ll notice that you have many different kinds of hunger. If it’s just a desire to eat, chewing something helps, or I’ll have a small snack (to satisfy the need for tastiness) along with a lot of water, tea or coffee (to fill up my stomach). Sometimes, I get hungry because I’m craving something particular, like protein, and listening to my body has taught me how to know what that feels like and how to resolve it.