Depression and Diet
This Food Fact Sheet will look at how following a healthy diet can help protect your mental health.
Eat regular meals
You need to feed your brain regularly with the right mix of nutrients for it to work properly. Unlike other organs, your brain relies on a steady supply of glucose (ideally coming from starch carbohydrates) as its primary fuel. Aim to eat little and often to keep your mood at its best.
Get the right balance of fats
Our brains are made of around 50% fat, and our cells need fats to maintain their structures, therefore an adequate supply of fats are needed to maintain health. You can read more on how to achieve a healthy balance of fats in your diet in BDA’s separate Food Fact Sheet on Fats, but in summary, try to keep a moderate intake of a good balance of fats in your diet, to ensure your brain is well nourished.
Try to use olive oil or rapeseed oil to cook with. Add nuts and seeds, and use olive or nut oil dressings on salads. As well as increasing unsaturated fats, try to decrease trans fats as these seem to be harmful to brain structure and function (as well as heart health). Trans fats are found in processed and packaged foods such as processed meats, ready meals, pre-packed cakes and biscuits. Instead try to use fresh foods and ingredients whenever you can.
Choose more wholegrains, fruit and vegetable foods
Wholegrain cereals, peas, beans, lentils, nuts, seeds, fruits and vegetables are rich in a range of vitamins and minerals that your body needs to function well. They are also digested slowly, helping to control the rate of glucose supply to your brain and body.
These foods are also rich in B vitamins, (including folate) and zinc, and recent evidence suggests that these nutrients are important in managing depression. Try to eat at least five different fruits and vegetables daily to get all the vitamins and minerals you need.
Include some protein at every meal
Eating protein as part of a ‘“little and often”’ eating plan also helps to keep us feeling full, which in turn, can prevent overeating. Tryptophan is one of the building blocks of protein, and research suggests that it may help with depression.
A diet with enough protein should contain plenty of tryptophan – good sources include fish, poultry, eggs and game, but some green leafy vegetables (such as spinach) and seeds also provide a source.
Fresh meat, fish, shellfish, eggs, milk, low fat cheese, nuts, seeds, lentils and beans are the best sources of protein.
Include oily fish in your diet
Some researchers think that omega 3 oils, found in oily fish, may help with depression. Aim for a minimum of two portions of oily fish per week (NB but not more if you are pregnant, breastfeeding or likely to become pregnant in the future). Oily fish include salmon, mackerel, herring, sardines, pilchards and trout.
- Make sure you start the day with breakfast, for example a wholegrain cereal such as porridge with milk and fruit, multigrain toast with a poached egg, or fruit and yoghurt and fresh fruit juice or smoothie to drink.
- Include some starchy food (such as boiled potatoes, rice, pasta, and granary or multigrain breads) at lunch and dinner. If you are short of time, then go for a sandwich or jacket potato (filled with fish or low fat cheese and salad) or even a bowl of cereal and some fruit.
- Between meals include snacks such as fruit, vegetables, nuts, yoghurts, and oatcakes, crackers with low fat cheese, meat or fish.
If you don’t like fish, you may decide to take an omega 3 supplement. If so, choose a fish body oil (these do not contain vitamin A) rather than fish liver oils. Too much vitamin A is stored in the liver and can build up to toxic levels and it can interfere with calcium metabolism.
When considering how much, the Scientific Advisory Committee on Nutrition (SACN) suggests eating a minimum of 450mg per day (3g per week) of long-chain omega-3 fatty acids. Find out more in BDA’s separate Food Fact Sheet on Omega 3.
Vegetarian sources of Omega 3 do not convert through to DHA and EPA (which are the forms of Omega 3 fat particularly beneficial to humans) very well. You can buy algae based supplements, but these are expensive. Alternatively, try omega 3 fortified foods such as eggs and milk.
Drink enough fluid
Evidence shows that even slight dehydration may affect your mood. Since we know that a healthy brain contains up to 78% water, it makes sense to drink plenty. Aim for 6-8 glasses (about 1.5- 2 litres) fluid per day.
Caffeine may affect your mood and may lead to withdrawal headaches and to low or irritable mood when the effects wear off.
Drinks such as coffee, cola, energy drinks, tea and chocolate all contain caffeine and should be limited. Drinking too much alcohol can cause dehydration and can lead to B vitamin deficiencies, which may make you more depressed or anxious. Limit your intake to no more than two to three drinks on no more than five days per week.
Alcohol also has a dehydrating effect. Drinking too much alcohol can also lead to B vitamin deficiencies, and can make you more depressed or anxious. Try to limit intake to no more than two to three drinks on no more than five days per week.
I am gaining/losing too much weight. What should I do?
First ask your doctor to review any medicines you are taking. Some are better than others at boosting appetite and a change may help you. If you are losing a lot of weight and are worried, ask to see a dietitian. If you are putting on weight it may make you feel more depressed. If you want to lose weight, try to exercise more.
Also, limit foods that are high in calories, such as pies, chips, puddings, cakes, crisps, chocolate, sugary drinks and alcohol.
Eat regularly throughout the day, including starch, protein and vegetables or salad at each meal to make sure your brain has a steady supply of energy.
Choose wholegrains, pulses, fresh foods, and fruit and vegetables. Minimise processed/packaged foods to make sure you get enough micronutrients to help your brain to function properly.
Ensure that you have a good balance of healthy fat intake to maintain the cell structure of your brain, including oily fish (omega 3 fatty acids) in your diet. Drink plenty of fluid (6 - 8 glasses non-caffeinated drinks) per day as even slight dehydration can affect your mood.
Download this information as a PDF.
This Food Factsheet is a public service of The British Dietetic Association (BDA) intended for information only. It is not a substitute for proper medical diagnosis or dietary advice given by a dietitian.
If you need to see a dietitian, visit your GP for a referral or a private dietitian.
Written by Lynne Harbottle, Dietitian. Reviewed by Gillian Farren, Dietitian.
© BDA April 2016. Review date April 2019.