Originally Posted by
GravelMN
Study be damned, if you burn more calories than you consume, you will lose weight, it is physiologically impossible to do otherwise as energy cannot be created, it can only change form. If the potential energy from your food = the kinetic energy of work performed, your fat stores will remain constant (notice I didn't say weight as weight can also include water/electrolyte issues). If our potential energy < the kinetic energy then additional potential energy from your glycogen and fat stores will be tapped and your fat stores will be depleted. The inverse is also true, that if your potential energy > the kinetic energy exerted, your body will store the excess as glycogen and fat.
You are right, but most people cycle their glycogen store endlessly and that's why they have such a hard time losing fat.
To lose fat, you must burn off your glycogen in your liver and muscles and not replenish it. When it doesn't have easy sugar to burn, your body will eventually start to burn fat. Your body will hate this and make you hungry, hungry, hungry for sugar. After a week or so of eating protein and green vegetables, the cravings will stop and you will start to lose fat. Very few people are willing to really cut sugar and starchy carbs for any length of times. Add to that the fact that people are told to replenish carbs when exercising and they stay fat forever.