Why Do High Protein Diets Work?

It all has to do with ghrelin and how the food you eat suppress it according to this article.

"The interesting findings were that fats suppress ghrelin quite
poorly," Cummings said in a telephone interview. They fared the poorest
overall.

"Proteins were the best suppressor of ghrelin in terms of the
combination of the depth and duration of suppression," he said. "That is truly
satisfying because high proteins are essentially common to almost all of the
popular diets."

They also found that eating carbohydrates resulted in a strong
ghrelin suppression at first, but ghrelin levels rebounded with a vengeance,
rising to an even higher level.

Basically, the carbohydrates eventually made people even hungrier
than before they had eaten.

So by eating carbs you end up hungrier after a few hours then by eating the same amount of protein. I know that by eating a high protein diet you end up not being hungry at all for hours at a time. You sometimes have to force yourself to eat. I guess this is because your ghrelin level drops really low so you just don't feel hungry at all. So in the meantime your body will burn off the fat that you have stored up for energy.