you need some protein in your lunch. ideally you should divide your calories into four small meals a day so if you calories for the day is only 400 then a small apple and water is a good lunch, if you need more calories than that figure out what you need in calories for a day and divide by 4. I usually eat yogurt and a small handful of nuts for lunch. but I eat a after work snack of about 200 calories at 4 pm. maybe some hummus and wasa cracker. don't skimp on lunch then gourge the rest of the evening that is not a good habit to get into.