Lunches for 400 Calories or Less. What does a 400-calorie lunch look like? Most people will lose weight on a daily diet of 1,500 calories, which is the total calorie count for all the food pictured here. And keeping your lunch to 400 calories, or less, will help you keep your diet on track. These light lunch menus deliver some protein and fiber to keep you feeling satisfied, yet leave room for a healthy mid-afternoon snack. Download a Free Low-Calorie Lunch Cookbook!