It also might be that you're mistaking the process and body signs of digestion for hunger. There is still food in your stomach after one hour, veggies don't digest that fast! But especially with fibrous foods your body will make gurgling, growling sounds as it breaks them down.
What other signs of hunger do you have? Lightheadedness, thoughts of food, weakness, shakiness?
I'm just throwing ideas out there and you can take them or leave them, but it might be that you're not hungry--just digesting.