This might be old news to a lot of people, but this is how you lose weight.

When you eat more calories than you burn in a day, your body stores those calories in some form, usually padding your body with fat.

When you eat fewer calories than you need to burn for the day, your body works on the 'reserves'.

Simple, right? So the answer looks very simple when you narrow it down to this.

Your body burns a certain amount of calories per day.

You eat a certain amount of calories per day.

When you can figure out the math, you can control your weight loss.

That's the secret. Nutrisystem, Jenny Craig and all the other programs work on the basis of controlling how many calories you take in during the day. They might have prepared meals, meal plans, recipes and suggestions. In some cases, you can take these programs, lose weight, and not even have to count a calorie or think about what you are doing. You just eat the food and go.

However, you could also follow the programs to a T and not lose weight, or lose weight really slowly.

You could also jump off the diet and gain all that weight back, and then some.

There's a reason for this: simple mathematics and genetics.

The genetics: Your body isn't the same as other people's. Your body might burn more or less calories during the day than other people.

The math: When you don't know how many calories you can take in a day to either lose weight or maintain it, how can you be expected to lose weight, or move forward after you have finished losing the weight?

Check back tomorrow for help on figuring out this formula.