Healthy weight

Healthy eating and your mental health

Healthy Food

Food and mood

We all have good days and bad days; we all have foods we like more, or like less. But is there a connection between feeling fine and the foods we have eaten? Do some foods make us feel grumpy? Is it possible to plan a diet for a good mood?

Vitamins and minerals

When you don’t eat enough nutrient-rich foods, your body may lack vital vitamins and minerals, which may affect your energy, mood and brain function.

In certain circumstances or for certain people, supplements may be beneficial e.g. folic acid for all women planning pregnancy; iron supplements for people diagnosed with anaemia; vitamin B12 for vegans and older adults, and vitamin D for everyone in winter months, and all pregnant and breastfeeding women, older adults, and people with dark skin.

Comfort eating

There is a messenger chemical in the brain called serotonin, which improves mood and how we feel. Serotonin is made with a part of protein from the diet (tryptophan) and eating carbohydrate-rich foods may help more of this get into your brain.

This suggestion has been used to explain ‘carbohydrate craving’ – eating sweet, comfort foods to boost mood. There is not enough research to show that eating lots of protein foods containing tryptophan or eating a lot of carbohydrates can really support mood improvement in humans. But it may be that not eating enough carbohydrates (for example through a high protein/high fat diet) leads to low moods.

You also may have heard the idea that eating chocolate can make you feel happier, and there are observations that people feeling down are more likely to eat chocolate. This is probably because chocolate is a well-known reward and comfort food, rather than due to any potent physiological effects particular to cocoa.

Carbohydrate = Glucose = Brain Power

To be able to concentrate and focus your brain needs enough energy, which comes from blood glucose. In fact, the brain uses 20% of all the energy your body needs.

Glucose is also vital to fuel muscles and maintain body temperature. The glucose in our blood comes from the carbohydrates we eat – including fruit, vegetables, cereals, bread, rice, potatoes, sugars and lactose in milk.

Not having enough glucose in your blood (hypoglycaemia) can make you feel weak, tired and ‘fuzzy minded’. This may happen when you don’t eat enough carbohydrate-containing food and is a particular risk if you have diabetes or do extreme exercise or manual labour. It can also happen if you follow a very restrictive diet or have irregular eating patterns.

Although glucose ensures good concentration and focus, once your blood glucose is within the normal range, you cannot further boost your brain power or concentration by increasing your glucose levels. If you are eating some carbohydrate foods, additional sugary ‘energy’ drinks are not needed and not helpful.

Caffeine and the ‘drug-effect’

Caffeine, found in coffee, cola and energy drinks, is often called a drug: it acts as a stimulant and can increase feelings of alertness, and counter the effects of fatigue. However, it may be that some of the effects of caffeine ‘normalise’ the lower levels of alertness felt by regular users who have not consumed enough caffeine that day.

Too much caffeine, particularly in people who are not used to it, may cause the adverse effects of irritability and headache. Such symptoms also occur with caffeine withdrawal in people used to lots of caffeine on a regular basis.

How diet and mental health are linked

The relationship between our diet and our mental health is complex. However, research shows a link between what we eat and how we feel:


  • Eating well can help you feel better. You don’t have to make big changes to your diet but see if you can try some of these tips.
  • Eat regularly. This can stop your blood sugar level from dropping, which can make you feel tired and bad-tempered.
  • Stay hydrated. Even mild dehydration can affect your mood, energy level and ability to concentrate.
  • Eat the right balance of fats. Your brain needs healthy fats to keep working well. They’re found in things such as olive oil, rapeseed oil, nuts, seeds, oily fish, avocados, milk and eggs.
  • Avoid trans fats – often found in processed or packaged foods – as they can be bad for your mood and your heart health.
  • Include more whole grains, fruits and vegetables in your diet. They contain the vitamins and minerals your brain and body need to stay well.
  • Include some protein with every meal. It contains an amino acid that your brain uses to help regulate your mood.
  • Look after your gut health. Your gut can reflect how you’re feeling: it can speed up or slow down if you’re stressed. Healthy food for your gut includes fruit, vegetables, beans and probiotics.
  • Be aware of how caffeine can affect your mood. It can cause sleep problems, especially if you drink it close to bedtime, and some people find it makes them irritable and anxious too.
  • Caffeine is found in coffee, tea, cola, energy drinks and chocolate.
family cooking together healthy food round the breakfast bar

Effect on mood – foods which can help 

Lack of iron

Not getting enough iron results in low levels of oxygen-carrying haemoglobin in the blood, resulting in the condition anaemia – feeling weak, tired and lethargic all the time.

The risk of anaemia is reduced by eating enough iron, particularly from red meat, poultry and fish, beans and pulses, and fortified cereals. Avoid drinking tea with meals.

Lack of Thiamin B1, Niacin B3 or Cobalamin B12 (all B vitamins)

Tiredness and feeling depressed or irritable.

Eat more fortified foods including wholegrain cereals, animal protein foods such as meat, fish, eggs and dairy.

Lack of Folate / folic acid

Increased chance of feeling depressed, particularly important in older people.

Folate is found in liver, green vegetables, oranges and other citrus fruits, beans and fortified foods such as yeast extract (marmite) and fortified breakfast cereals.

Lack of Selenium

May increase the incidence of feeling depressed and other negative mood states.

Foods such as brazil nuts, meat, fish, seeds and wholemeal bread can help.

healthy foods including nuts, seeds, fish and veg

So does food affect mood?

There are many ways that foods can affect how we feel, just as how we feel has an influence on what foods we choose.

Some of the mood/food effects are due to nutrient content, but a lot of effects are due to existing associations of foods with pleasure and reward (chocolate) or diet and deprivation (plain foods).

Some foods also have religious, economic and cultural significance, which will influence how we feel when eating them. 

Eat a healthy balanced diet


Feeling good comes from a diet that has enough healthy choice carbohydrates at regular times to keep blood glucose levels stable, and eating breakfast is a sensible habit.

Protein, vitamins and minerals

Diets should also contain a wide variety of protein and vitamin and mineral-containing foods to support the body’s functions.

Fruit and vegetables

As a rule, plenty of fruits and vegetables and wholegrain cereal foods, with some protein foods, including oily fish, will support a good supply of nutrients for both good health and good mood.

Need help to manage your weight?
Find support local to you

If you wish to make a referral into the Feel Good Suffolk service, your Feel Good Suffolk Advisor can support you to access information contained on this website or community assistance local to you.

They can also advise you on the eligibility criteria for more intensive levels of support around managing a healthy weight, stopping smoking and being more active.