If you’ve ever felt inexplicably anxious, flat or irritable and found yourself rummaging through the cupboards for comfort, you’re in good company. You’d be hard-pressed to find someone who hasn’t leaned on something sweet or salty at some point, hoping it might lift their mood or take the edge off after a tough day.
The trouble is, while food can soothe in the moment, diving headfirst into a packet of chocolate biscuits can make things worse in the long run. There’s now a growing body of research showing that what we eat has a direct and measurable impact on our brain chemistry, hormones and emotional wellbeing.
Yet, according to nutritional biochemist and Bio Blends founder Dr Libby, mood struggles are still too often treated as purely psychological, with nutrition left out of the conversation.
“What we eat literally becomes part of us,” Dr Libby explains. “Every single cell and biochemical reaction in our body requires nutrients to function effectively. This includes the building of neurotransmitters and hormones that influence our mood, emotional resilience and sense of calm.”
In other words, food isn’t just fuel – it’s information for the brain.
Why nutrients matter for emotional wellbeing
When we feel anxious, low or emotionally fragile, it’s common to assume stress, life circumstances or mental health alone are to blame. While those factors certainly matter, Dr Libby says nutritional deficiencies are often hiding in plain sight.
“There is a tendency these days to go down a purely psychological or psychiatric path when we feel anxious, flat or not quite ourselves emotionally,” she says. “Yet, what often gets missed is a comprehensive review of a person’s nutritional status to consider whether there are deficiencies that may be influencing our biochemistry in ways that leave us feeling anxious, depressed or with mood fluctuations.”
One of the most significant – and most overlooked – is iron. “Anxiety is a listed symptom of iron deficiency and the most common nutritional deficiency in the world, including in Australia, and it’s not being addressed adequately,” Dr Libby says. “Many people of all ages falsely believe they have an illness when they are actually iron-deficient.”
Iron is essential for the production of dopamine, serotonin and GABA – three neurotransmitters that help regulate mood, motivation and calm. Without enough of it, emotional wellbeing can suffer, regardless of how well we’re sleeping or managing stress.
Beyond iron, nutrients such as zinc, vitamin D, selenium and iodine are needed to produce progesterone, a hormone that, as Dr Libby notes, is “an anti-anxiety agent” in its own right. All of these nutrients come from food, making our daily choices more influential than we might realise.
The blood sugar–mood connection
Mood swings, irritability and sudden emotional crashes can sometimes be traced back to what’s happening with blood sugar. “Your brain relies heavily on glucose for energy,” Dr Libby explains. When levels spike and then drop rapidly, it can trigger feelings of anxiety, teariness or irritability, often described as being ‘hangry’.
When blood sugar falls, the body has a backup plan: adrenaline. “Being the hormone that’s also responsible for your fight, flight, freeze response, it can create feelings that mimic anxiety like heart palpitations, light perspiration, shakiness, restlessness, and feeling on edge,” she says.
Over time, repeated blood sugar swings can leave us emotionally reactive and depleted. The fix isn’t cutting carbs entirely, but eating in a way that steadies energy.
“To prevent blood sugar spikes and plummets, focus on including protein, nourishing fats, whole food sources of carbohydrates (rather than ultra-processed ones) and plenty of vegetables in each meal,” Dr Libby advises. “Consistency is key.”
How gut health shapes our mood
The gut–brain connection is no longer fringe science – it’s central to mental health. “Many of the neurotransmitters associated with mental health are built in the gut,” says Dr Libby. “Up to 80 per cent of our serotonin, for example, is made in the gut and then transported to where it needs to go, including to the brain.”
Specific strains of gut bacteria also help produce dopamine and GABA, meaning a compromised microbiome can directly affect mood. Chronic stress, low vegetable intake, excess sugar and frequent antibiotic use all disrupt the delicate pH balance of the digestive tract and, in turn, emotional health.
“Add to this the overuse of antibiotics, and we have a perfect storm of gut-driven poor mental health that all starts with food and how we digest it, and it’s not discussed enough in connection to our mental wellbeing,” Dr Libby says.
Why stress makes us crave sugar and caffeine
That mid-afternoon coffee-and-something-sweet craving isn’t a failure of willpower, it’s biology. “We may live in a modern world, but our bodies are still playing by ancient wiring,” Dr Libby explains.
Stress, pressure and worry trigger adrenaline, a hormone designed to help us survive danger. Historically, that meant we needed fast fuel – sugar – and alertness. “So when we’re stressed, we seek to keep ourselves alert, and we tend to use caffeine and sugar to do this,” she says.
The problem? “It’s a vicious cycle for so many people that can keep us stuck in an anxious loop, without awareness of what’s driving it.” Over time, nutrient-poor choices crowd out nourishing foods, increasing deficiencies and emotional vulnerability, and leaving us feeling worse about ourselves in the process.
Nutrients that support a calmer mood
Certain micronutrients play an outsized role in emotional balance. Dr Libby says our best bet for improved mood is to add more of these to our weekly shopping lists:
- Iron: offal, red meat, mussels, sardines, eggs, seaweed, lentils, peas, green leafy vegetables
- Zinc: oysters, red meat, eggs, sunflower seeds
- Magnesium: green leafy vegetables, nuts, pumpkin seeds
- Omega-3 fatty acids: wild-caught oily fish, linseeds, algae, walnuts, chia seeds
- Omega-6 fatty acids: evening primrose oil, borage oil, blackcurrant seeds
Inflammation, food sensitivities and mood
Chronic low-grade inflammation – often driven by stress, sleep deprivation, poor diet and gut issues – can quietly undermine mental health. “Yes, absolutely, all of this can impact mood,” Dr Libby says.
If food sensitivities are suspected, tuning into how you feel after meals is a powerful first step. “We want our food to enliven us and fuel our energy, not drain it or make us feel sluggish, depressed or anxious,” she says. “Our body doesn’t have a voice, but it does communicate to us through our symptoms.”
Mood-supporting food habits to start today
- Eat protein, healthy fats and complex carbs at every meal
- Don’t skip meals if you’re prone to anxiety or irritability
- Prioritise iron-rich foods, especially if you still get your period
- Include plenty of vegetables to support gut health
- Notice how caffeine and sugar affect your mood, not just your energy
And remember: While it’s normal to have ups and downs, persistent low mood shouldn’t be ignored. If you’re not feeling like yourself for weeks at a time, or your mood is interfering with everyday life, make an appointment with your GP or healthcare provider.
