In very basic terms, we eat to live.
And each of us will have an individual ideal calorie intake each day that will give us just enough of the 'good' stuff like nutrients, vitamins and minerals and energy to keep our bodies functioning as they should, and allow us to do just that...
live.
Eat less than you should and you may well get sick, eat more than you should (or eat the wrong stuff) and you'll gain weight...
and that may also result in you getting sick.
If you are taking in too many calories on a regular basis, then your body has to work out how to deal with that excess.
If you lead a sedentary lifestyle where you don't get much exercise at all, then you won't see many of these calories actually being burned up or used by your body.
You're far more likely to see them stored, and the problem here is that your body doesn't just store them as easily accessible items to use up later - it will convert them and store them as fat, in all the wrong places.
In a way it's really quite easy to work out whether you are burning calories each day or storing them.
If you take enough exercise to burn up the right amount of calories and therefore match your calorie intake, then the chances are you won't have too many (if any) problems with your weight.
On the other hand if you aren't getting any or enough exercise relative to how much you eat, then you'll know that you're storing excess calories because your weight will be higher than it should, and there will be a few extra flabby lumps and bumps around your body...
on your stomach, hips, thighs, back, neck, arms, legs, ankles for example.
There are various ways to deal with this "match up your calories" issue.
Some people, for example, will simply take the approach of working out what their ideal calorie intake should be and then make sure that what they eat each day doesn't exceed that total of calories.
Others will simply exercise enough every single day to try and make sure that their calorie intake doesn't have the chance to turn to fat in the first place.
They will burn up all they eat, and sometimes more.
Many people who do manage to maintain a healthy weight take the view that their best route to success here is to count their calories every day and to make sure that they get enough exercise to burn off any excess.
This may also give you the added bonus of knowing that you can occasionally add a high calorie treat to even a low calorie diet and use extra exercise as a solution to burn up the excess.
So, are you burning calories or storing calories? Is your weight growing each month, or is it at a steady level, or declining? If it's heading in the wrong direction for you and your health, it might be a good idea to take some action.
Now! And remember, your lifestyle (the amount of exercise you get) plays as much of a part in the way that your body responds to what you eat as the actual number of calories you eat.
So, if you are already at the right weight, you could (as an example) maintain your optimum weight by simply taking time to work out how many calories you should limit yourself to, taking your lifestyle or exercise into consideration...
and sticking with those.
Most of us however are probably in the "storing calories" part of the equation.
We therefore need to take some action today, increase our exercise and decrease the amount (or change the type) of food we consume.
Then we'll see results.