Protein and Hormones
Protein is used to make hormones, which are messengers in the body. They're produced in one part of the body and then distributed – through blood, interstitial or other body fluid – to other organs or tissues. There they modify activity and function.
This brief article will focus on just a few hormones and how they affect appetite.
• CCK (Cholecystokinin)
Satiety is the feeling that you do not need another meal because you're still satisfied from the last one.
CCK is arguably the most powerful satiety hormone in the body. It reduces appetite by stimulating the function of the brain's key satiety center, the VMH (ventromedial hypothalamus).
CCK is released when we eat protein and fats. It affects our food preferences by reducing the desire for carbs.
Anyone who suffers from an exaggerated desire for carbs probably needs to eat more protein. Vegans, for example, may experience strong cravings for carbs, including sugars.
Finding a true protein source is a key factor in decreasing vegans' cravings. More on that in Part 3.
Eating adequate protein can also be key in conquering sugar addiction for this same reason.
Ghrelin increases appetite by stimulating the brain's lateral hypothalamus. The LH can be seen as a 'feeding' center.
Eating protein can help to reduce ghrelin release. In healthy men, a high protein breakfast reduced post-meal ghrelin levels more than a high-carb breakfast. The high-protein meal also slowed gastric emptying. Researchers attributed both effects to the secretion of CCK and glucagon, both triggered by protein.
Glucagon is a hormone made in the pancreas. Insulin is, as well, but the functions of the two hormones are oppositional and work to balance glucose levels.
Insulin also tends to have a fat-storage hormone, while glucagon moves fats out of storage and into the blood stream so they can be utilized as fuel, rather than stored.
While many foods trigger the release of insulin, only protein foods trigger glucagon. Glucagon is also secreted when we exercise.
As mentioned above, glucagon and CCK seem to effect appetite control by modifying ghrelin levels.
Do not miss protein and brain chemistry, age, and the vegan solution in Part 3, right here this week!