I dont want to offend anyone, but fark it - the greatest truths are offensive.
This is my job, 12 hours a day, 6 days a week I do this. I no longer train clients how to get into shape, I train trainers how to get their clients into shape. I am good at this.
It all comes down to carbohydrates. Sorry, its just true.
As carbohydrate intake raises, insulin rises, as insulin rises fat storage goes up, and fat burning almost completely stops. On the same key, as insulin rises, hunger for carbohydates increases, and as hunger for carbohydates increases, cabrohydrate intake does as well.
Its a cycle Eat Carbs = store fat, stop fat burning, increase hunger, repeat.
Eating a lower carb, higher fat, higher protein diet forces the body to use ketones, body fat, as fuel, decreases hunger, yet increases fat burning rate (known as lipotic thermogenisis - this comes from the increase of fat burning hormones that occurs during a low carb high fat diet).
The truth is, my clients consistently eat more calories per day then they should be buring, yet loose body fat, build muscle, and increase metabolism.
The reason this makes since is quite honestly, the concepts of calories makes no sense. A calorie is the amount of energy needed to raise 1 gram of water 1 degree in temperature, it is a rule of thermodynamics, and it makes sense that to over burn what is available, you would have to expend more heat energy than what is present, and on the same token, if not enough heat energy is present to burn what is available - it would be left over. Basic. One problem, this is a rule of THERMODYNAMICS! Our bodies are not thermodynamic machines, they are bio-chemical machines with multiple cascades of hormone interactions which play a much larger role than heat energy when it comes to either fat storage or fat use.