If you’re blaming age or stress for low mood and brain fog, zoom out.
Modern eating patterns—desk lunches, late coffees, not enough fibre—can quietly drain the nutrients your nervous system needs to make serotonin and dopamine.
Even “normal” blood tests can miss low-normal levels that still feel awful.
Start with food. A few targeted upgrades can give your brain the building blocks to bounce back.
Why what you eat shapes how you feel
Mood is not just mindset. The brain runs on nutrients. B-group vitamins, magnesium, omega-3s and iron help make neurotransmitters like serotonin and dopamine that steady mood, focus and motivation. When those raw materials are missing, thinking your way out of a slump is hard work.
“The brain is heavily nutrient-dependent. If the building blocks aren’t there, no amount of mindset work will fully shift how you feel,” says clinical nutritionist at Cell Squared, Emma Claire.
B12: the clarity vitamin
Vitamin B12 act as support crew for your nervous system. It helps form myelin, supports red blood cells and is involved in neurotransmitter production.
Low intake or absorption can look like fatigue, brain fog, low mood, pins and needles or subtle balance changes.
You can sit in the “normal” range on a blood test and still feel off, especially if absorption is reduced by low stomach acid, gut issues or a long-term vegan pattern without reliable B12 sources. If symptoms ring true, speak with your GP about a check that includes B12, folate and iron, plus a plan that suits your diet.
The gut–brain loop, made simple
About 90% of the body’s serotonin is made in the gut. A diverse, fibre-rich diet feeds gut microbes that produce short-chain fatty acids, which signal along the gut–brain axis and support calmer mood.
“A thriving microbiome sends stabilising signals to the brain. An imbalanced one can fuel stress and anxiety,” says Claire.
Everyday foods that support mood and energy
Start with easy wins in your trolley and on your plate. These staples feed the gut–brain axis, steady blood sugar and supply the raw materials for feel-good neurotransmitters.
- Oily fish like salmon or sardines two to three times a week for omega-3s that support brain structure and anti-inflammatory pathways.
- Root veg such as sweet potato, carrot and beetroot to steady blood sugar and feed beneficial gut bacteria.
- Iron and B12-rich proteins including lean red meat, eggs and, if you eat them, small amounts of organ meats. If organ meats are not for you, focus on food sources you enjoy and discuss alternatives with your GP or an accredited practising dietitian.
Small shifts that help in burnout or low mood
Pair smart nutrition with simple routine tweaks. These habits calm the nervous system, support hormone balance and make steady energy easier to maintain.
- Build meals around protein to stabilise energy and cravings.
- Add healthy fats from fish, olive oil, avocado and nuts for longer-lasting fullness.
- Front-load sleep to 8–9 hours where possible. Good sleep supports hormones and lowers inflammation that can magnify emotional reactivity.
- Light and movement early. Morning daylight and a walk or gentle cardio help circadian rhythm and mood. Save higher-intensity sessions for morning, keep afternoons easier.
Habits to dial down
You do not need to be perfect. Just be mindful of the big drains:
- excess caffeine
- Alcohol
- ultra-processed foods
They can spike and crash blood sugar, irritate the gut and fragment sleep, all of which can cloud mood. Cutting back often makes you feel calmer and clearer within days.
Make it doable, not daunting
Perfection is not the goal. Stack easy wins:
- Swap a processed snack for boiled eggs or a handful of nuts.
- Add one extra serve of veg at lunch.
- Plan two protein-rich dinners for the week and repeat.
- Keep frozen soups or casseroles on hand for low-energy days.
“Prioritise nutrient-dense protein, especially foods naturally rich in B12 and iron,” says Claire. “They are the foundation for making neurotransmitters that regulate mood and energy.”
Low mood, fatigue or tingling can have many causes. If symptoms persist, worsen or affect daily life, see your GP promptly.
Ask whether bloods for B12, folate, iron studies, thyroid function and vitamin D are appropriate for you. Supplements may help in deficiency, but food-first and clinician-guided plans are safest.
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