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How food affects your mood

Throughout the day we are regularly exposed to things which can have a negative effect on our mood. It could be the weather or a particularly challenging day at work that turns your positivity sour and, unfortunately, these aspects of our lives are usually difficult to control.

But we can take back some control by ensuring that our bodies are set up to respond to what the day throws at us. Here's what to eat to ward off those negative feelings.

There are many dietary factors that can affect our mood but one key aspect that evidence has shown makes a big difference is our blood sugar. To retain optimal function, the brain and the rest of the body need a steady supply of glucose, or 'blood sugar', to maintain concentration and general mood.

What should my blood sugar level be?

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Blood sugar

We get blood sugar from the food we eat. Eating the right food regularly is important.

After food is swallowed, the digestive system breaks it down until it is in a useable form. Some of this will be sugar, which is then released into the bloodstream. A hormone called insulin then enters the blood to unlock our bodies' cells to let the sugar in, providing them with energy.

Ever feel 'hangry'?

Many of us are familiar with the term 'hangry' (ie being hungry and angry) and, believe it or not, the idea that when a person is hungry they are also angry does have some scientific backing.

If blood sugar levels drop too low too quickly we tend to feel tired, unable to concentrate, and short-tempered, and often crave sugar.

This quick drop occurs when we eat foods that provide a big, sudden release of sugar into the blood at once. It creates a panicked response from the body which triggers a big influx of insulin to allow the sugar to move into cells. Due to the quantity of insulin released, blood sugar falls rapidly, causing a sensation of low blood sugar.

If you have diabetes and use insulin (or if you have type 2 diabetes and use sulfonylurea tablets), these treatments can cause your blood sugar to drop well below normal - a hypoglycaemic episode, or 'hypo'. This causes the same symptoms of irritability and poor concentration.

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Keep blood sugar steady

To ensure that we have a stable level of sugar in the blood, we need to eat foods that are slow to break down in the body so that they provide a slow and steady release of sugar into the blood and cells. This helps to maintain mood and also keeps you feeling fuller for longer.

Which foods release energy slowly?

Foods with complex structures are slow to break down and so release energy slowly. They include:

  • Wholegrain pasta, rice and bread

  • Legumes

  • Fruits and vegetables

  • Meat

  • Poultry

  • Pulses

  • Nuts

  • Dairy

Which foods release energy quickly?

Foods that are simpler in structure and higher in sugar are quick and easy to break down. They include:

  • Sugary drinks

  • Sugary cereals

  • Processed meals

  • White pasta, rice and bread

These are the foods which, as described previously, cause a sudden overload of sugar in the blood, which prompts a big influx of insulin that results in a quick drop in blood sugar levels and, in turn, can negatively impact mood.

Brain food

Studies have identified that on the whole, a well-nourished brain is a happier brain. So as well as making sure it has a steady supply of energy, it can also be beneficial to make sure that you consume brain-friendly nutrients including:

B vitamins, especially B9 otherwise known as folate (poultry, eggs, dairy, fortified cereals)

B vitamins are involved in many processes in the brain. One of these is the production of a chemical called serotonin which is often found to be low in those with depression. In fact, many drugs that are used to treat depression work to increase serotonin production, so eating a diet rich in B vitamins is a natural way to boost this mood enhancing chemical.

Omega 3 (oily fish, flax seeds, walnuts)

Like the B vitamins, omega 3 has many beneficial functions within the brain. Importantly, omega 3 helps to reduce the production of chemicals which can lead to inflammation, which in turn has been linked to low mood and anxiety.

Prebiotics and Probiotics

  • Prebiotics: live bacteria found in fermented foods, artichokes and garlic.

  • Probiotics: a source of good food for the bacteria already present in our gut; found in some dairy products with live cultures.

The gut-brain axis is becoming an increasingly well-known term as time goes by and for good reason. Recent studies have found that the good bacteria in our gut are, like B vitamins, capable of supporting the production of our good-mood chemical serotonin. Therefore eating a diet which contains both live bacteria and the foods that they like to eat is a great way to increase serotonin levels.

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A typical good mood food menu


Porridge made with oats and milk topped with toasted flaked almonds and chopped apple.


A handful of carrot sticks with a tablespoon of hummus.


Mixed salad containing a complex carbohydrate such as roasted sweet potato and a good source of protein such as tuna, pulses or hard-boiled egg.


A pear and a small handful of walnuts.


Chicken and vegetable stir fry with egg noodles.



Article history

The information on this page is peer reviewed by qualified clinicians.

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