When you feel stressed, you probably experience one or more of the “fight,” “flight,” or “freeze” reactions. These reactions are related to stress hormones that impact your physical body when your brain feels threatened or challenged. You have probably heard of the stress hormones like adrenaline and cortisol. But, the more we look into human physiology, the more we learn.
Of course, there are so many symptoms of stress, one of which is the need to start searching around for a quick, convenient snack. That’s a pretty common experience, and now researchers have uncovered a link as to why.
A recent study published in the journal Nutrients looked through a number of studies to see how much evidence there really is for this potential link between stress and hunger. What makes this study pretty compelling was that it’s not based on just one study, but a combination of studies. In fact, ten studies met their quality criteria (rating at least a six out of eight on their assessment), so they put them together and looked for a “birds-eye view” of what was going on.
What they found consistently through these ten studies was that when people were subjected to stress, they released another hormone called ghrelin.
Ghrelin was discovered in 1996 and became known as the “hunger” hormone (it has several functions, but appetite-regulation seems like the main one). Ghrelin is a protein-based hormone released mainly by the stomach. Ghrelin is also called the hunger hormone and causes an empty stomach to start grumbling.
When people were exposed to short-term stress (e.g., their non-dominant hand is placed in ice water for two minutes) the levels of ghrelin quickly increased, and slowly decreased as minutes and hours went by. Another interesting thing is that we don’t know why ghrelin decreases after stress is removed. We used to think that ghrelin levels reduced after finding and eating food, but that wasn’t the case here. More studies will shed light on this in the future.
Researchers wanted to take this one step farther. Because we know that stress is tied to excess weight and excess weight is a source of stress, they wondered if the stress-ghrelin response was different in people experiencing overweight and obesity. They found that people with excess weight tended to have even higher levels of ghrelin that lasted even longer than stressed people without excess weight. It’s not clear right now which comes first: increased ghrelin in response to weight or increased weight in response to ghrelin, but there certainly seems to be a correlation.
The overall conclusion is that, yes, ghrelin the “hunger” hormone is also a stress hormone and people experiencing overweight and obesity tend to experience higher levels of ghrelin when under stress. Often when we are stressed and hungry we tend to eat junk food which is affects our health and weight.
It's important to find ways to reduce stress. Research demonstrates that stress affects our health and can lead to weight gain. Start today and incorporate stress reduction in to your daily routine.