You have the basic idea, but their is a little more to it.Overall wgehit *is* as numbers game, meaning that if the calories you take in are less than the number required to "run" your body you will lose wgehit.One pound of fat equals 3500 calories. You can either cut that many calories from the diet, or you can burn them with additional exercize. For example:If you cut 500 calories from your daily diet after one week that would equal 3500, so you would lose one pound. Or you could burn 500 extra calories a day by jogging an hour at the end of a week it would equal one pound lost.If you Cut 500 calories per day AND jogged for an hour (500 cal) that would equal 2 pounds per week. And so on Except there is a minimum amount of calories and nutriets your body REALLY likes to take in, otherwise it makes some hormonal changes that conserve energy by slowing your metabolism. Most diets say to not go under 1200 cal a day, but that is usually considering a person of average height and wgehit. If you are taller, or already overweight you may need signifigantly more calories to prevent dropping into metabolism hibernation.To answer your question, if you eat 1200 calories, that is your intake. It doesn't matter if you burn an equal amount right away Except for very simple carbs (sugar) most food take a while to digest and is not used immediatly for energy. Even simple carbs aren't used right away unless you have already exhausted all the glycogen stored in your liver.Remeber the 1200 you burn at the gym would be ON TOP of the other 1200 calories required to run your body as normal Breathing, Sleeping, Healing, Walking around etc all take calories too.Let's imagine you normally eat 2000 calories per day. You look online and see your minimum caloric intake should be 1500. This means you should not cut more than 500 calories per day from your diet. You could lose 1 lb per week by diet alone. If you want to lose more wgehit weekly you would need to do it by exercise. If you tried to cut your diet down to 1000 the whole thing would likely backfire.There is also so smaller effects related to hunger hormones related to glycemic index of food, but that starts to get a little technical..Hope this helps!