Starving!

I’ve been trying to eat healthier and smaller portions, but it’s been difficult for me. If I go too long without eating or if I don’t eat enough I get hunger pangs which can get pretty painful, so I usually eat something like a small sandwich and a glass of milk to get full or just snack on something little. Any tips on how to keep the hunger pangs at bay? I already go on walks around my neighborhood every night when I get the chance, but diet is just as important to weight loss and healthier lifestyle as exercise is.