"Eat less for lunch. Also, try to live an active/healthy life style by doing a bit of cardio everyday and to eat properly (lots of fruits/water/etc).
Or take the easy route and drink a lot of coffee, like most people do haha :)"
"When you just had lunch/dinner/whatever and there's food inside your stomach, it goes to work. Your body will focus a bit more energy on your stomach and a bit less on the rest of your body. If your condition is not so good, or the meal is…"