Anyone know what is a healthy lunch for a teenage during summer?

Light. A balanced meal with complex carbohydrates, not high in fat and with some protein would be ideal. Include some fruit if possible. Avoid lots of simple sugars and excessively spicy food. This could upset the stomach if exercising or doing sports.
Good question. I will not suggest a menu today, but common sense dictates - no overeating (if you feel the first sign of stomach fullness, you must stop). Also, there is a number of "unhealthy foods" that i recommend to avoid - coke products, high calorie foods - pizza/french frieds, chips, dressings, certain meats - pork, bacon, friend foods. I'm not saying here not to eat those at all, but to limit those.