The Food-Mood Connection: Low Carb Diets and Mental Health
Food and mood are prime rhymes, but these nouns have more in common than just their sounds. Mental health, once considered a matter of brain chemistry and heredity, is multifaced. Journalist and Author Johann Hari, known for his books on addiction and mental health, attributes depression and anxiety to disconnection – from meaningful work, values, human relationships, and community.
Additionally, we’ve become disconnected from real food, and by extension, real nutrition. This is problematic because poor mental health has a direct correlation with what we eat, particularly refined carbohydrates. Adopting a low-carb diet can bring us more into balance, connection, and sound emotional health.
The Food-Mood Connection
Aside from rhyming, food and mood have a cause-and-effect relationship. Although bio-individuality dictates that food can have different effects on different people, when it comes to sugar, our bodies all respond unfavorably. Let’s dive into some ways sugar affects us physically and emotionally.
Fatigue & Irritability
You’re probably familiar with that energy slump that comes from eating too much sugar. There are several reasons for this. Firstly, excess sugar counteracts the effects of orexin, a neuropeptide chemical in the brain that makes us feel alert. Additionally, too much sugar can spike our blood sugar, which sets us up to crash soon after. This leads to crankiness and irritability. Often times we experience burnout (our tank is on empty) without considering what fuel we’ve been putting in our bodies.
These sugar highs and lows can become a vicious cycle. We eat sugar for energy, only to crash, and then seek out more sugar to dig us out of the hole. Words like “hangry” have been invented to acknowledge how much our mood and energy are affected by low blood sugar.
The signaling of dopamine, a neurotransmitter that controls the pleasure and reward center in our brain, is also impacted by sugar. As with any type of over-exposure, scientists believe that over time, if dopamine keeps increasing at fast and frequent rates, we can become desensitized to it, which leads to addiction. Soon one cookie won’t cut it, and we need to eat the entire box to get that same high.
Sugar impacts several other neurotransmitters and hormones in the brain which produce “happy” feelings, including beta endorphin (involved in pain reduction) and serotonin. Fun fact: Roughly 90% of serotonin is produced in the gut with the help of our beneficial bacteria! Sugar can starve out these good bacteria, leading to less serotonin production.
Every time we eat sugar, we feel good. The problem is that these good feelings are short-lived, and we wind up feeling worse. Exercising produces endorphins which also make us feel good, but for many of us, a carton of ice cream is more appealing in the moment than a treadmill.
As we ride the sugar rollercoaster, our mood tends to tag along, which is encouraging because when we stabilize our blood sugar, our mood follows suit. Adopting a low-carb diet is one way to help blood sugar (and mood) stabilize.
Memory, Learning, and Brain Fog
Excess sugar forces our pancreas to produce more and more insulin, a hormone that lowers our blood sugar. If we keep pumping out too much insulin, over time this process can make us resistant to insulin. This is not only bad news for our blood sugar, but also our memory and focus.
In addition to lowering blood sugar, insulin helps strengthen the connection between synapses in our brain. We need strong connections between synapses for learning and memory. Suffice it to say, it’s better not to develop insulin resistance. Sugar can also negatively affect Brain-Derived Neurotropic Factor (BDNF), a protein needed for cognition. Among other things, BDNF helps us form new memories and remember old ones.
As a result of the disruption sugar causes to various hormones and neurotransmitters, brain fog is a common feeling brought on by high-sugar diets. Brain fog is often alleviated when refined sugar is removed from the diet and replaced with quality protein, healthy fats, and low-carb foods.
Slow digesting sugars from complex carbs and fiber (fruits, veggies, and whole grains) can help fight off many diseases, even ones you may be predisposed for. However, processed, refined sugar has the opposite effect. Consuming too much processed sugar has been linked to high blood pressure and inflammation, and by extension, inflammatory diseases such as heart disease, type 2 diabetes, obesity, and Alzheimer’s.
Anxiety and depression are two sides of the same coin. When blood sugar is volatile, our moods can sway back and forth from extremely sad to extremely anxious. Excess sugar consumption is linked to depression and anxiety not only through blood sugar spikes, but through inflammation, hormonal imbalances, and disturbances to the gut microbiome.
The Gut-Brain Connection
Our gut is connected to our brain via the vagus nerve, a superhighway of hormones and neurotransmitters constantly passing information back and forth. In the gut, is our gut microbiome, a universe of bacteria and viruses that digest food, synthesize vitamins, and influence production of neurotransmitters (like dopamine and serotonin). These neurotransmitters send important chemical messages to our brain, namely, to feel better.
A healthy diet not only helps strengthen the vagus nerve, but it helps our beneficial bacteria flourish. A strong microbiome enhances production of these necessary “happy” brain chemicals. Conversely, high-sugar diets not only kill off these beneficial bacteria, they cause inflammation within the body which interferes with the gut-brain axis.
If low blood sugar makes you feel anxious, you’re not imagining it. Holistic psychiatrist Dr. Ellen Vora uses nutrition whenever treating her patients. She says that if we’re feeling anxious and don’t know why, we should take stock of our blood sugar and whether we ate refined carbs earlier that day, because low blood sugar and anxiety are linked.
Anxiety and low blood sugar share many of the same symptoms – dizziness, nausea, sweating, rapid heart rate, shakiness, hunger, panic attacks. This is not a coincidence. Here’s why:
Some of the sugar we ingest is immediately converted to glucose for energy, and some is stored in the liver as glycogen for later. Think of glycogen as extra resources, but in order to use these extra resources, our body has to produce more hormones and chemicals to gain access. When our blood sugar drops:
- our pancreas releases glucagon, a hormone which tells the liver to convert the glycogen back to glucose, so we can gain energy,
- our body produces adrenaline which instructs the liver to make glucose, and
Adrenaline, the “fight or flight” hormone and cortisol, the “stress hormone,” both shoot up in moments of sheer terror and anxiety. It makes sense when you think about it: We need energy (glucose in our blood) if we’re about to run for our lives!
In other words, anxiety and low blood sugar share the same symptoms because the same hormones are elevating, causing the same physiological reactions in the body. Together, adrenaline and cortisol help to raise our blood sugar, but the price we pay in return is heightened anxiety.
In cases of ADHD, more research is needed to establish whether high-carb diets have a causal effect on the disorder. However, doctors agree that reducing sugar can help alleviate symptoms. High protein diets complete with adequate healthy fats (such as a Keto diet) are generally recommended to manage ADHD symptoms, along with a reduction of processed sugar (including honey, high fructose corn syrup, and refined flour).
Barriers to Adequate Nutrition
Unfortunately, eating a healthier diet may not be possible for everyone. In fact, there’s a catch-22—eating healthfully can improve mental health, but mental illness itself may pose challenges to healthy eating.
Access to healthy food is not always readily available or affordable for many people suffering from mental illness. Additionally, those who struggle with mental illness may not have the education or resources (such as nutritionists and health coaches) to help them adopt a healthier diet. Finally, some individuals may be contending with a suppressed appetite as a side effect of medications they’re taking. All these factors can pose difficult barriers to using nutrition as a tool to heal.
But for those who are fortunate enough to be able to make dietary adjustments, it’s worth a go. The research is clear: There is a strong connection between high-sugar diets and depressive symptoms, repeated spikes and drops in blood sugar, inflammatory medical conditions, mood disorders, and increased risk for anxiety.  
How Low-Carb Diets Can Improve Health
Diets high in sugar and other refined carbs are linked to a variety of physical and mental diseases and exacerbate symptoms. But the damage sugar can cause can be avoided and, in many cases, reversed, when we are more discerning about the type of carbs we eat.
We know it can be challenging to change what we’re used to—sweet midday snacks, pick-me-ups, sugary desserts after dinner, carb-heavy dishes in social situations and on holidays. Thankfully there’s a variety of delicious low-carb foods that can make the transition easy and, dare I say, enjoyable.
Foods to Boost Mental Health
Foods high in tryptophan are great for boosting emotional well-being. Tryptophan is an amino acid that helps make serotonin, our happiness hormone. However, the body does not produce tryptophan on its own, so it’s important to get it through diet. Some foods that contain tryptophan are: meat, eggs, poultry, fish, butter, peanuts, almonds, and cottage cheese.
Other foods to include for better mood:
Healthy fats for omega-3 fatty acids
- Sardines and other fatty fish
- Nuts and seeds
Whole grains, protein, and fiber for energy and stable blood sugar
- Brown rice
- Beans and lentils
Fermented foods to feed the beneficial bacteria in the gut
- Plain Greek yogurt
Naturally occurring sugar to satisfy your taste buds
- Dark chocolate (70% or higher)
Low-Carb Recipes to Try
For a boost in mood and improved mental health, make your own savory Keto meals.
- Garlic Butter Steak Bites with Lemon Butter Zucchini Noodles from Eat Well
- Stir Fry from Big Man's World
- Bacon Wrapped Meatloaf from Delish
- Baked Buffalo Chicken Wings from Wholesome Yum
- Chicken Parmesan and More from Women’s Health
Don’t forget about dessert! Check out some of our favorite low-carb/high-taste treats!
This information is not intended to prevent, diagnose, prescribe, or treat any illness or condition, nor does it take the place of sound medical advice. You should always seek out your own medical care and determine the best diet and course of treatment for your unique health needs.
 Gangwisch JE, Hale L, Garcia L, et al. High glycemic index diet as a risk factor for depression: analyses from the Women’s Health Initiative. Am J Clin Nutr2015;102:454-63. doi:10.3945/ajcn.114.103846 pmid:26109579
 Seaquist ER, Anderson J, Childs B, et al., American Diabetes Association, Endocrine Society. Hypoglycemia and diabetes: a report of a workgroup of the American Diabetes Association and the Endocrine Society. J Clin Endocrinol Metab2013;98:1845-59.doi:10.1210/jc.2012-4127 pmid:23589524
- A low carb diet can be beneficial for maintaining positive mental health.
- Volatility of blood sugar levels and other internal system disturbances can affect your mood and focus.