YOUR diet should be much more than A diet. It's not a short-term fad plan, it's a lifestyle. Try to eat reasonably healthily, limit fats and sugars, focus on leaner meats and veggies, limit starches and carbs (which turn into sugar while you are still chewing them up). Your diet should be driven like your finances - by a budget that you plan and control. If you want to spend more in one place (eat more of one thing), then you have to balance it out over time or across other spending (eating) categories. Unlike a budget, though, there are calories that are more valuable for the same denomination than others. A silver dollar is worth the same as a paper dollar at the store, but 300 calories of Twinkies are not worth the same as 200 calories of grilled chicken and broccoli or green beans or asparagus. At your tender young age (or at least when I was that age) you might well be able to pretty much whatever you want and in whatever quantities sound good at the time. You will find that if you live long enough (into your late 20's or 30's) that the habits you form now, including eating habits, will not change much, while your metabolism will tend to slow down significantly. A healthy diet (with occasional Twinkies, but not at every meal, and not a box at a time) along with steady endurance/aerobic exercise (running, biking or swimming for example) and some strength training (weight, nautilus machines, or my favorite body-weight exercises like pushups, pullups, and crunches) will help keep your metabolism running a little more quickly, which means both more calories you can take in and more things in life that you'll be able to do. You don't have to live on chia seeds and water, but you need to manage your diet as closely as you manage your money (which you also need to start paying close attention to if you haven't already). Basics here, but the details are largely up to you and your body.