How Dieting Can Affect Your Mood

Disclaimer: Results are not guaranteed*** and may vary from person to person***.

diet affects moodMerely saying that food affects how you feel is not a revolutionary discovery. Inventive terms like “comfort food” and “hangry” (yes, “hangry”—slang for an irritable or angry mood when hungry) exist for a reason, after all. However, it is a gross oversimplification to say things like being hungry makes us upset or eating treats can make people feel better.

There are very real biological mechanisms at work here that affect not only our short-term emotions, but also long term mental health and mood. Learning about the nutrients and diet styles that can cause our moods to shift and swing is a big step in knowing how to develop an overall positive lifestyle.


Tryptophan—also known as “that thing in the turkey that makes you sleepy”—is an amino acid that’s found in most protein-rich foods. Aside from its more famous effect, tryptophan increases the production of serotonin when absorbed by the brain. Serotonin is a powerful mood regulator made from a mixture of tryptophan and the vitamin B family. Low levels of serotonin are associated with depression and other mood disorders.

You may be expecting this to lead to a recommendation to eat more turkey, but it’s not quite that simple. There are numerous other amino acids that are much better at reaching the brain. When this happens, they take up the receptors that tryptophan would normally use, hindering its ability to get absorbed further.

The solution to this is carbohydrates, as they help collect and remove tryptophan’s competition. Naturally, you will want to choose smart sources of carbs. Next time you have a turkey breast, try it with a side of whole grains, fruits, vegetables, or legumes. You’ll get a good pairing of tryptophan and carbohydrates, plus fiber and other nutrients to boot.

Skipping Meals

Waking up late, an early commute, or feeling fine with just a cup of coffee are common reasons why people don’t stop and have a proper breakfast, and losing track of time from being too busy is an often-heard excuse for missing lunch. Missing either meal poses a problem for a few shared reasons.

First, no matter what you think you can do on an empty stomach, your body will strongly disagree. Hunger increases fatigue, affects concentration, and makes people more irritable and anxious. Plus, those hunger pangs aren’t going to do you any good.

The second reason is that you cannot simply skip meals and expect to eat later without repercussions. Your body is remarkably intelligent in a number of ways, but it has a habit of overcorrecting. It doesn’t know, for instance, that you slept in late or that you were busy with meetings all day and couldn’t grab a meal. All your body knows is that it hasn’t been fed in some time and really wants some nutrients. Therefore, when you next eat, your body will hold on to as much as it can. This is a lesser version of the “yo-yo dieting” effect. Eating inconsistently not only makes your mood more volatile, it doesn’t help your ability to lose weight either.


Our taste buds love fat—that’s why it’s in so many commercial products. Our bodies like fat too, since it forms our natural long-term energy stores. However, saturated fats like those in potato chips, or any high-fat meal in general for that matter, can almost immediately make you feel sluggish and maybe even a little gross. This is because fat is not the easiest thing to digest and process. Your body needs to focus more on digesting it, leading to increased fatigue and a sluggish feeling.

The key to balancing the fat in your diet is to recognize ways it can be reduced or cut out. If you put cream cheese on your bagel, go with a fat-free variety. If you put milk in your coffee, reach for the skim. Avoid red meat if you can, but if you do end up getting a steak you should aim for the extra-lean variety. Being alert and using some common sense replacements can help you avoid getting slowed down by your meals.

Omega-3 Fatty Acids

Omega-3s are used for a few different things in the body, one of which is neurotransmitter pathways in the brain. The exact mechanism isn’t understood yet, but it’s been theorized that the prevalence of oily fish in Japanese diets is why that country has one of the lowest rates of depression. More generally, omega-3s have been noted to improve memory and mood—no doubt helped by how fish is one of the foods that can boost serotonin levels.

Other sources of omega-3s are fortified eggs or milk, along with flaxseed and walnuts. You should aim for two to three servings of oily fish or another omega-3 source per week.


The world’s most popular stimulant can make you feel alert and energetic, perfect for starting the day. Unfortunately, some people take it too far and have caffeine in most of their drinks. This can be anything from coffee-addicted adults to soda-slurping teens. Even if you don’t drink enough caffeine to cause anxiety, depression, or high blood pressure, high doses can make you dehydrated.

An adult loses around 2.5 litres of water every day through a mixture of perspiration, urination, and exhalation. Caffeine is a diuretic, meaning it makes you pee more. This means extra water loss that results in a regular intake of caffeinated drinks not always being enough to offset the amount lost daily. Mild dehydration may not be life- threatening, but it still impairs concentration, mental acuity, and makes us irritable.

The Tip of the Iceberg

These are just a handful of examples. Almost every nutrient can have some effect on your mood. Either having it can improve how you feel or lacking it can make you feel worse. The key, therefore, is to maintain an effective dietary balance in order to eat regularly and get the right nutrients that you need to stay active and feel better.

Sources for Today’s Article:
“Diet and Mental Health,” Mental Health Foundation web site;, last accessed September 3, 2015.
Haupt, A., “Food and Mood: 6 Ways Your Diet Affects How You Feel,” U.S. Health News web site, August 31, 2011;
Magee, E., “How Food Affects Your Moods,” WebMD web site;, last accessed September 3, 2015.