
How does intake of food and drink affect mental health?
There is evidence:
- A healthy diet (high in fruits, vegetables, nuts, and legumes; moderate amounts of poultry, eggs, and dairy products; and only occasional red meat) is associated with a reduced risk of depression.
- Omega-3 fats can improve mental health. These are found in fish like tuna, salmon, mackerel, perch, herring and sardines, and in smaller amounts in white fish such as cod, bass, haddock and snapper. 2 to 3 meals a week of oily fish will provide enough omega-3.
- Diets high in refined carbohydrates (such as snack foods) can increase the risk of symptoms of depression.
Eating well hlps prevent some diseases like diabetes, which also affect mental health.
Being overweight or obese can contribute to mental health disorders. Some medicines for mental illness also cause weight gain, which adds to the problem. Losing weight through better nutrition and exercise can improve mental health.
Eating habits can also affect sleep and therefore mental health. It’s best to have your main meal 2 to 3 hours before bed. If hungry, a piece of fruit or a glass of milk is a good bedtime snack.
Some foods interfere with the medicines used to treat mental health disorders.
Some examples are:
- Foods containing high levels of tyramine (aged, matured or fermented like aged cheeses or cured meats) should not be eaten if you have been prescribed an antidepressant called a monoamine oxidase inhibitor (MAOI).
- Grapefruit and grapefruit juice interferes with many medicines including some taken for mental health disorders.
- Your salt intake if you are prescribed lithium can significantly change the level of lithium in your blood.
Supplements can be helpful but not always necessary. They can have side effects and can interact with medicines for mental health disorders. For example, St John’s Wort can be dangerous if taken with some antidepressant medicines.

Water
For good mental health, it is important to drink plenty of water. Water is needed to make neurotransmitters, the chemicals that transmit signals between brain cells and hormones that control the processes of the body and brain. Even mild dehydration can make you irritable and affect mental performance.

Alcohol
Alcohol is a depressant. While it can make you feel good for a while, drinking too much alcohol can affect your mental and physical health.
Short term, drinking a large amount of alcohol (binge drinking) can lead to psychological effects such as impairing your judgment or causing you to deliberately harm yourself or others.
Long-term use of alcohol increases the risk of depression, anxiety and other mental health disorders. It can also lead to dependence and addiction, especially in people who have depression or anxiety, and it can increase the risk of suicide.
Alcohol also affects sleep and therefore mental health. It can make you feel drowsy and help you fall asleep, but often negatively affects your sleep during the second half of the night. Alcohol can interfere with how well some medications work, and increase their side effects such as drowsiness and dizziness.

Caffeine
Caffeine is a stimulant that acts on the brain and nervous system. It is found in coffee, most teas, cocoa, chocolate, cola, guarana and energy drinks.
Caffeine might have some positive effects on mental health. For example, it might help with depression by reducing inflammation in the brain. But caffeine is addictive, and many regular coffee drinkers become dependent on it.
Caffeine can increase anxiety and alter sleep patterns in some people. You should avoid caffeine for at least 4 hours before going to bed.
Caffeine can also interact with some medications used to treat mental illness.

How can I improve my eating and drinking habits?
People with mental health disorders can use the same strategies as everyone else to eat a balanced diet, drink enough water, and limit their intake of caffeine and alcohol.
However, some people with mental health disorders might have more difficulty than others because of:
- lack of motivation
- loss of appetite, or comfort eating
- using drugs or alcohol as a coping strategy
- irregular meals
- feelings of isolation
- financial insecurity
If you are struggling to eat and drink more healthily, these strategies might help.
- Mindful eating: If you concentrate on what you’re eating, you will probably eat more healthily. For example, people who eat while watching television tend to eat too much at one sitting. Practising mindfulness and being aware of what you are doing has its own benefits.
- Healthy food swaps: It can be easier to make small changes than big changes. They’re more likely to stick. Swap white breads for wholegrain breads. Swap the frying pan for the grill.
- Going easy on yourself: Change doesn’t usually happen overnight. Take small steps to improve your food and drink intake, make changes and practise positive self-talk.
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