I would have to say the most unhealthy group of people would have to teenagers. We eat so much junk food because its there and ready and no effort required. Now some of us do take the healthy option of subway or sumo salads or even some of those health food stores that they have in shopping centres. But for the majority its either Mc Donald's, KFC, pizza or hungry jacks. with some of the food sold at these stores its calorie intake is enough for 3 or more days- clearly not good for you. But being teenagers and staying up late at night and waking up just in time to shower and get on the bus for school we neglect making ourselves a sandwich or grabbing an apple, instead we would rather buy from the school canteen which in most cases isn't the most healthy option either. So if we must continue buying from the school canteen try something healthy like a salad or a piece of fruit because they are there. But if not at school eat one or two when u get home make some balance in your diet. You will find u will feel a lot better when you wake up in the mornings and when you do things in general, healthy food is the key to a long and enjoyable life.