The Biochemistry Behind Appetite Regulation

We are already in a situation of massive public health failure. As Americans, we have allowed individuals in society to function within a system that has failed them.

But the question remains — how did we get here?

Our Bodies Love Carbohydrates…

Our bodies love carbs.

Source

The Building Blocks of Proteins

The proteins we consume are essentially broken down into 20 different amino acids. In order to sustain life, our body requires all 20 of them, although not all of them are considered “essential.” 9 of them can only be acquired through our diet; our body does not have the capability to produce them. The other 11 can be manufactured by our cells even when they are not part of our diet.

Energy Sources and Utilization

Since our bodies require a constant source of energy, but not an endless supply of food, it is crucial for us to be able to store these excess surpluses of macromolecules.

Hypothalamic Energy Regulation

Our hypothalamus serves as our master endocrine gland, controlling many of the hormones involved in appetite regulation.

Arcuate Nucleus

The arcuate nucleus, on the lower right of the image on the left, serves as the receiving station for many hormones. In the middle of the arcuate nucleus is a small white triangle, representing a fluid-filled cavity which is referred to as the third ventricle. This allows for cerebrospinal fluid to flow through the arcuate nucleus and distribute the rich supply of hormones produced by the arcuate nucleus to the body.

NPY/AgRP Neurons

POMC/CART Neurons

Orexigenic Hormones and Neurotransmitters

Hormones and neurotransmitters that are orexigenic stimulate our appetite and are released when the stomach is empty. There are dozens of orexigenic hormones, but 5 main ones take precedence:

Anorexigenic Hormones and Neurotransmitters

On the other hand, anorexigenic hormones and neurotransmitters act as appetite suppressants. When the levels of these chemical messengers are increased, you feel full and your appetite is suppressed. Although there are many, 5 of them play the largest role in appetite suppression:

A Well-Regulated Cycle

The well-regulated cycle takes into account many assumptions. In order for our appetite to work in this manner, we have to assume reliable and constantly available food sources, that all critical biological processes and running normally, regular hormonal secretion, that the body can use and store energy, signal to the brain that it is full, and consequently reduce an individual’s appetite.

Biological Diversity

There are certain natural mutations in our genes that also change how our bodies regulate our appetite. A study conducted by researchers at Cambridge recruited almost half a million individuals and sequenced their genes, focusing on the genes that encode for the receptor for MSH, released by POMC/CART neurons. These hormones bind to a receptor called MC4R (melanocortin-4 receptor).

Hormones are chemical molecules, but they serve no function if they are unable to bind to a receptor.

In this study, researchers looked for natural variations in the gene that codes for the MSH receptor. Due to the complexity of our species, we all have subtle variations in our genetic makeup. Point mutations in our DNA can still make fully functioning receptors. However, mutations can sometimes lead to differences in the way the receptor will function.

16 y/o working in healthtech & women’s health | a collection of my thoughts | manasigajjalapurna.com