Part I: the fat cell

The science behind “fat burning” is extremely interesting, but even though there is detailed scientific knowledge about what happens in our bodies when we change caloric intake, it seems like many of us have an almost “superstitious” idea about body fat. We hear “fat burning” and think that good diet and exercise make fat simply flow away into some imaginary furnace.

What really happens is that our bodies use diet and exercise as keys to unlock a collection of fat cells and stimulate specific chemical processes that actually make fat cells smaller. We don't “lose” fat cells, but instead, we “empty” them.

A more specific scientific explanation goes like this: a fat cell or “adiposyte” stores a product called “tryaglycerol”. This stuff response to some very specific stimuli by getting turned into what's called “fatty free acids” or FFAs. These FFAs are then released into the bloodstream.

That’s how your good diet and exercise pattern works. This stimulus for releasing the fatty free acids is this: the body expands more calories than it has recently ingested. Since there is no caloric energy readily on hand, the body “reaches” for stored caloric energy in the fat cells. Specific enzymes and hormones trigger the changing of tryaglycerol into fatty free acids and it's released into the bloodstream. The primary agent is called Hormone Sensitive Lipase or HSL: as the blood pumps during vigorous exercise, chemical elements like HSL send fatty free acids to where they are needed.

This explains why the equation of exercise plus good diet works: good diet keep your caloric intake down. However, vigorous exercise such as cardio training is the key, as that's when the body ends up needing the stored fat.

Without the specific equation, fat can build up pretty quickly. Throughout the path toward adulthood, it's estimated that the average person's number of fat cells goes up about 500% (from 5 or 6 billion cells in a baby to 25-30 billion in an average adult). However, with excessive caloric intake and without calorie burning, that number can go up by tens of billions, until the obese individual is storing extra calories in up to 60 or 70 billion fat cells.

By researching this, we can see that there is a twofold process to staying thin: individuals have to limit the creation of new fat cells, and find ways to deplete the stored up fat stored in the existing fat cells. We also see that no “fat cell burning” gets done. We find that in order to practice healthy lifelong habits, and individual needs to be vigilant about making sure that excessive calories don't end up creating a vicious cycle of not just “hypertrophy” (more energy getting dumped into fat cells) but also “hyperplasia” (the creation of large additional numbers of fat cells). A better knowledge about how “fat burning” works can lead to much better solutions for controlling weight gain and fighting obesity.

Read part II : burning fat (the intake)