If i eat 1200 calories a day, will i lose weight no matter what?

Yes. Work 0ut your BMR (Google search) which is the amount of calories your body burns just with metabolic processes (heartbeat, digestion etc) NOT physical activity. Eat less than that, your body has to burn fat to fuel these processes = weight loss.

There are a lot of factors involved, but yes, most people will eventually lose weight if they eat a diet of 1,200 calories a day. If you can bump it up to 1,400 or 1,500 calories and exercise consistently, that would be healthier. You might lose weight slower this way, but you'd be more likely to keep it off.

You would, but you would find yourself getting sick. Your body needs nutrients to function well, and if you are still growing, you will not grow properly and as a consequence will have health problems when you get older. These things won't be apparent now, but you could regret bad eating habits in your later years. Eating well NOW will also make you feel great. Try to get your calories from healthy foods high in nutrients. http://www.sparkpeople.com is a website that helps people lose weight while establishing a healthy lifestyle that will help them keep it off for good. If you end up being too young for it, it will suggest some other sites geared just for young teens and pre teens. I highly suggest you check them out, they are very informative and helpful, and you will learn a lot, probably enough that you won't have to ask questions here again! I know your question about junk was hypothetical, but don't let yourself get tricked into thinking that it's okay to eat junk for a day as long asyou keep your calories down. It's perfectly okay to treat yourself to "junk food", but you should be smart about it when you do it. Try to be good to your body and give it what it needs to keep you healthy! :) Take care, and good luck to you

Yes and no. The main rule is, burn more calories than you put in your body and you'll loose weight. But if you fill your body with empty calories, such as sugars, you won't be able to burn those calories very efficiently. Also, if you eat a bunch of fats and carbs before bed and your body will convert it into fat instead of burning it for energy. "starvation" diets rarely work. It might bring short term weight loss but in the long wrong your metabolism will adjust and you'll be right back where you started. Eat right not less.

Im pretty sure you would. I learned in health that the key to losing weight is to burn off more calories then you consume, and since the human body generally burns 1,800 calories on it's own due to bodily functions, plus the calories from any sort of physical activity you might be doing, you would lose weight (it may not be very fast though, and belly fat is the last to go). The girls on my school's Competition Cheerleading Squad who are 1-3 pounds overweight get put on strict diets of no more then 1500 calories a day. if you are too overweight, then you are put on Drill Team or as a Base for Freshman squad. Im on Varisty as of now, and I find that whole diet thing rude, stupid, and shallow.