The amount of calories needed per day is determined by such factors as your level of physical activity (daily calorie expenditure), your state of health, and whether you want to gain weight, lose weight, or maintain weight.
Calories can make you gain weight, but it depends mostly on two things: the amount of exercise you do a day, and the amount of calories you are consuming. I watch my calorie intake and what I eat, and I run 3 or 4 times a week, and I'm losing weight... so it really depends.
It depends on the type of calories you are eating, avoid processed food and things such as fast food. You should focus on eating a healthy diet and not necessarily on counting calories.
An average person might burn around 480 calories per hour playing football. However, it depends on such things as your weight, your degree of fitness, and how hard you are playing.
It depends on which things you do, and for how long :)
by simply eating one certain food group and doing a good amount of exercise
It depends on many things and can take just a few years or many centuries.
Your weight, age, gender, general health, how active you are, and even how much you think (since the brain consumes a relatively high amount of glucose).
There is no way to answer how long it will take to lose weight because it depends on the calories that are being eaten daily. Three things a day may have more calories than six or ten things a day. Losing weight depends on one thing: calories in = calories out.
Calorie intake depends on a lot of things, like height, weight, gender, age, activity level, muscle mass, and frame size.
Depends on a lot of things, but maybe 300 calories.
It depends on the person. It vaires greatly based on things like gender, age, body type, weight, and a variety of other factors.
It depends on what you mean. Calories give you energy and energy helps you move, talk, and do other things so in a way, yes you do need calories to grow.