For those of you who have experienced the “munchies” after ingesting cannabis and wondered why that happens, this article is for you. And just like everything in the cannabis world, there are different theories about any particular subject. In this article I will list the four factors that signal hunger, discuss the difference between appetite and hunger and will explain two different theories.
Four Factors That Signal Hunger
When you are sober, there are four factors that influence the sensation of hunger and fullness, according to information disseminated by the University of Michigan Department of Medicine. They are:
- Signals sent from the hypothalamus which controls appetite among other functions
- Hormone levels
- Blood sugar levels
- Feeling of emptiness or fullness in the stomach and intestines
- Appetite vs Hunger
Appetite is somewhat different from hunger. Your appetite can be stimulated by the aroma of your favorite foods even when you are not actually hungry. Appetite can also be stimulated or suppressed by stressful situations.
How Cannabis Impacts The Hunger Signal
1. Ghrelin, The Hunger Hormone
According to cannabis specialist Dr. Melanie Bone, the production of the hormone, ghrelin, known as the “hunger hormone,” is responsible for the stimulation of the appetite. It is considered to be a gut hormone as it is mainly produced and released by the stomach. Small amounts of the hormone are released by the small intestine, pancreas and brain. It has other functions in addition to appetite stimulation such as an increase in food intake and the promotion of fat storage.
The cannabinoids in cannabis can accentuate the taste and smell of food. This is very useful for those who have a depressed appetite due to many different conditions which can be medical and/or psychological. Often patients who have a poor appetite and are underweight experience pressure from friends and loved ones to eat more. This, in itself, can cause anxiety and stress surrounding eating which can exacerbate the problem. Dr. Bone cites the use of the cannabinoids, CBD and CBG, to reduce the anxiety associated with food for those with psychological and social problems.
Fear of Weight Gain
On the other side of the spectrum, many patients who embark on the use of medical cannabis for reasons other than appetite stimulation worry about the possibility of weight gain. When Dr. Bone encounters patients concerned with weight gain, she explains that long-term cannabis users typically have normal or even low body weight, and a lower BMI than non-cannabis users.
2. Cannabinoids Shut Down Proopiomelanocortin (POMCs)
In February 2015, the findings of a study, Hypothalamic POMC Neurons Promote Cannabinoid-Induced Feeding, on how cannabinoids affect normal brain function, was published in Nature. The main authors of the study are Tamas Horvath, professor of neurobiology at Yale and Marco Koch of the University of Leipzig. The focus of research for Horvath and his team is how the brain controls food intake, appetite and satiety. When the two researchers met, they discovered they both were interested in studying how cannabinoids interfere with normal brain function. They and their teams collaborated to investigate.
They discovered that when the neurons in the hypothalamus, POMCs, which control fullness, are exposed to cannabis, the pathway messages become scrambled which essentially turns them off. In other words, when you give animals cannabis, they will continue to eat even if they are sated.
Here is where it gets interesting. When the researchers exposed mice to cannabinoids, by way of injection, the opposite happened. The POMCs were turned on even more than usual. Typically, POMCs secrete the chemical alpha-melanocyte-stimulating hormone (alpha-MSH) which acts to provide feelings of fullness. When mice were exposed to cannabinoids, the POMCs released a completely different chemical called beta-endorphins, responsible for stimulating the appetite and enhancing cravings. This suggests that the neurons whose function is to stop us from eating were flipped into making us want to eat more.
This made the researchers wonder if cannabis actually rewires the human brain, albeit only temporarily. In addition, are there other neurons whose function is turned upside down when they are exposed to cannabinoids?
Researchers Turn Off POMCS in Sated Mice
The researchers wanted to see what happened when they artificially turned off the POMCs in mice that were full. The intention was to make them overeat when they ordinarily would not in order to simulate a human smoking cannabis directly after eating a large meal. When they exposed these mice to cannabinoids, they hardly ate anything. Next, they artificially intensified the POMCs in another group of well-fed mice and exposed them to cannabinoids. The animals couldn’t get enough food and gorged themselves. What this indicated to the researchers is the possibility that cannabinoids cause brain function changes due to the flipping of the function of neurons in other parts of the brain.
It is interesting to note that although this is certainly not the first study to explore the impact of cannabinoids on causing “the munchies,’ it is the first one to investigate the impact of these particular neurons on it or in this capacity. Horvath and his team want to conduct further research on the role that POMCs play in the overall feeling of being stoned.
Another avenue to investigate is the impact that cannabis has on the olfactory bulb in the brain which makes food smell and taste much better than it typically does. The researchers are coming around to the notion that “the munchies” is more than likely a complicated physiological response to several different sets of neurons.
The other important finding in this study may explain why regular cannabis users aren’t all morbidly obese. When you use cannabinoids, POMCs secrete endorphins that increase your appetite while simultaneously producing the alpha-MSH chemicals that decrease your appetite. Once the effects of the cannabinoids wear off, the POMCs release alpha-MSH which depresses the appetite and re-establishes homeostasis which, theoretically, does not cause weight gain….unless you continuously ingest cannabis and eat nonstop!
weedmaps.com, Why Does Weed Make You Hungry?
vice.com, This Is Why Weed Gives You The Munchies, Matthew Zuras, April 19, 2017