When you don’t eat, you get hungry. For some people, hunger affects them in a way that makes them angry, or as some people say, “hangry” (hungry + angry). This is a response to the body not having adequate nourishment on hand to keep the brain functioning at a high level, though not everyone who gets hungry becomes hangry. In fact, everyone’s body is different and each person will respond differently to different levels of hunger, satiation, and even different measures of nutritional intake. So, if being hungry can affect your mood – which it can – does your diet also affect your mood?

The answer to that question is yes, generally speaking. Your diet, or your nutritional intake, plays a large role in your physical health, which in turn affects the other parts of your being: mental, emotional, etc. Being healthy, and without discomfort, can have a large impact on how you feel emotionally. As the old adage goes, “You are what you eat.” Studies show that your brain responds differently when it is well-nourished versus when it is missing key nutrients. Other studies have looked into a person’s gut bacteria and its role in that person’s mood. Let’s dive into these findings.

Food and the Brain

Harvard Medical School’s health blog is a great resource for information based on current scholarship. One such article applies nutritional psychiatry to how our brains operate, based on the food that we eat. There, the author compares our brains to cars, saying that premium fuel helps our brain run at its best, whereas less-than-premium fuel (unhealthy foods) will decrease our brain’s productivity and longevity. It goes further and suggests that poor nutrition can affect a person’s overall mood, including exacerbating the symptoms of depression.

In order to ensure that your brain is receiving the nutrients that it needs to operate in peak physical shape, you will want to make sure that you are eating a well-balanced selection of foods, including vegetables, fish, and nuts, so that you are ingesting enough macro and micro-nutrients to power your body.

Gut Bacteria and Your Mood

Another article published by Harvard Medical School’s health blog discusses how a person’s gut bacteria (the human microbiome) can affect their mood. There, they discuss how processed foods can interrupt a healthy gut environment, increasing a person’s risk of contracting an illness or developing a disease. In addition to the health risks associated with a poor diet and an unhealthy gut biome, researchers also address how the gut can affect a person’s mood.

Almost 95% of a person’s serotonin is produced in the gastrointestinal tract. Serotonin is a neurotransmitter that helps with regulating a person’s sleep, appetite, mood, and pain inhibition. An unhealthy gut biome can lead to a lower serotonin level, which can lead to a more unpredictable and unhappier mood.

To help ensure that your gut’s microbiome is healthy, you should look at what you are eating. The more processed a food is, the less likely it is to be helpful to your gut microbiome. Adjusting your diet is the first and most productive step you can take. In addition to eating a healthier, more balanced diet, you may also want to consider adding good bacteria to your gut through probiotics or other means. It may be a good idea to consult your doctor before starting a probiotic, but you can always try adding a daily, low-sugar yogurt to your routine – make sure that it contains probiotics, though, as many do not.


As we’ve shared, studies prove that your diet can affect your mood. For those who are struggling to regulate their mood, or have recently experienced exacerbated symptoms of depression or another mental health problem, changing your diet may be helpful. If you do decide to change your diet, try to eat whole foods, including fruits and vegetables. Likewise, try to eat enough fiber while also reducing your sugar intake. A healthy, low-sugar probiotic (like yogurt) can also help. Of course, there are things that a healthy diet cannot treat, and in those instances, it is always a good idea to ask for help from a friend, family member, physician, or certified psychiatrist who is trained for exactly that purpose.