Eating well and mental health

This information is for everyone who wants to eat healthily. It's particularly for people who feel that their mental health problem or its treatment has affected them in the way they eat.

Eating well can mean different things to different people. Broadly speaking it means eating in a way so that:

  • our weight remains normal – not too low and not to high
  • our weight remains stable – not going up and down all the time
  • all necessary food groups and vitamins are available
  • eating becomes and remains an enjoyable experience.


This leaflet provides information, not advice.

The content in this leaflet is provided for general information only. It is not intended to, and does not, mount to advice which you should rely on. It is not in any way an alternative to specific advice.

You must therefore obtain the relevant professional or specialist advice before taking, or refraining from, any action based on the information in this leaflet.

If you have questions about any medical matter, you should consult your doctor or other professional healthcare provider without delay.

If you think you are experiencing any medical condition you should seek immediate medical attention from a doctor or other professional healthcare provider.

Although we make reasonable efforts to compile accurate information in our leaflets and to update the information in our leaflets, we make no representations, warranties or guarantees, whether express or implied, that the content in this leaflet is accurate, complete or up to date.

Eating well helps us to prevent many diseases which are linked with being overweight.

Diseases include high blood sugar, high blood pressure, heart problems, stroke, cancer joint problems and sleeping difficulties just to name a few.

Eating well also makes us feel emotionally well.

Why is eating well important for people with mental health problems?

People with mental health problems are more likely to have a weight problem. The reasons for this are not fully clear.

For instance, some people always feel tired and just not up to any activity. Others always feel hungry.

Some of this may be related to the mental health problem itself; however it has increasingly become clear that weight problems may also be a side-effect of some treatments.

This does not mean one should stop treatment because one might become mentally unwell again. Sometimes it is possible to swap to another medication. Alternatively, one can try to become more physically active or switch to better eating habits.

On this webpage we look at eating habits.

Let’s start with finding out what foods there are.

Foods can essentially be divided into three groups:

  • carbohydrates or sugar based foods
  • fats
  • proteins

Please be aware

We can only give general information but not consider individual cases.

If in doubt, you should discuss your diet with your nurse, a doctor or a dietician.

Also, the guidance given here applies to adults only and not to children who have different dietary needs. If you are pregnant or suffer from certain physical health problems your dietary requirements may also be different.

What are they?

Carbohydrates are essentially made up of sugar. There are simple carbohydrates made up of just one or several sugar units (glucose or fructose) and there are complex carbohydrates made up of long chains of sugars.

These long sugar chains are called starch. Complex carbohydrates often contain a lot of fibre.

Simple carbohydrates are broken down easily in the body and may give an instant but short-term effect. Complex carbohydrates take longer to break down but have a longer effect. Each gram of carbohydrate provides approximately four calories of energy.

What are carbohydrates used for?

Carbohydrates are the main fuel of the body. For instance, muscles work most effectively on glucose although they can also burn fat.

Under normal conditions, the brain also operates on glucose as its main fuel.


  • Simple carbohydrates are found in foods like glucose, sugar, jam, honey, sweets etc. They are also found in many fizzy drinks and sports drinks. Complex carbohydrates are found in foods like fruits, root vegetables, beans and potatoes, grain products such as bread, pasta, rice and couscous. Breakfast cereals also contain complex carbohydrates, but many brands also contain considerable amounts of sugar.

What is the glycaemic index?

This is a measure of how fast a food is broken down into single sugar units, i.e. glucose. The longer it takes, the lower the glycaemic index (GI).

The glycaemic index does not only depend on the length of the sugar chain, but also on the fibre content. That is why white rice and white bread, where the outer layer is removed from the grain, have a much higher glycaemic index than brown rice and brown bread.

Foods with a low glycaemic index are often called “good carbs”, and foods with a high glycaemic index are called “bad carbs”.

The glycaemic index, however, only measures glucose, but not fructose. So the glycaemic index can underestimate the sugar contents of foods that have a lot of fructose or table sugar (which is made up of a combination of glucose and fructose).

Because of this, the glycaemic index may be lower than expected for many pastries, fruits, soft drinks and fruit juices, and it does not give information about calories. High fat snacks, such as peanuts, have a low glycaemic index, but they are extremely high in calories.

What happens if I eat too many carbohydrates?

If you eat more carbohydrates than your body needs to burn as fuel then the excess will be converted into fat and stored.

Which carbohydrates should I eat?

Try to eat “good carbs” with a low glycaemic index. Goods carbs include fruits, vegetables, and legumes such as beans, pasta, brown rice, basmati rice, whole meal bread and potatoes.

Fruits can vary considerably in free sugar content. For instance, bananas may contain up to 21% of free sugar, whereas oranges tend to contain about 9% and strawberries only 6%.

What are fats?

Fats are made up of chains of fatty acids. There are three different types of fatty acids which are defined by their chemical structure and by their ability to take up additional hydrogen atoms.

This sounds very theoretical but has very important health applications as they differ in their ability to promote bad (LDL) or good (HDL) cholesterol.  One gram of fat yields approximately eight calories.

Unsaturated fats are made up of fatty acids that can store additional hydrogen atoms. If only one hydrogen atom can be taken up they are monounsaturated, and if several can be taken up they are called polyunsaturated.

Unsaturated fats are usually liquid, this means they are oils. They can lower blood cholesterol levels.

Saturated fats cannot store an additional hydrogen atom. They are already fully loaded, in other words saturated. They are solid and they raise cholesterol.

Trans-fats are unsaturated. They can be produced from oils by introducing some hydrogen atoms into oils so that they become solid and do not go off that fast.

That is why trans-fats are mainly used for industrial food production.  Trans-fats have been linked to an increased risk of heart disease, although not everybody agrees.

What are fats used for?

Fats serve many different purposes. They are an important energy store which can be activated when the body has run of glucose. 

Fat deposits insulate the body against the cold. Fatty acids are also important components for cell membranes and hormones and may even have a role in keeping us mentally stable.  Fats are needed to make use of some vitamins such as vitamin A, D, E and K.


  • Unsaturated fats are found in foods like vegetable oils, for instance sunflower- and olive oil, olives, nuts, seeds and avocados.
  • Saturated fats are mainly found in animal products such as milk, butter, cheese, cream and meats and dairy products such yoghurts, puddings or ice cream. Note that coconut products including coconut paste or milk are also high in saturated fats.
  • Trans-fats are found in hardened vegetable oils such as margarine and spreads. Trans-fats can also be found in instant soups and sauces and cake mixes. Mass-produced foods like cakes, biscuits and chips may contain large amounts of trans-fats.

What happens if I eat too many fats?

The fat deposits of the body will be extended.

Which fats should I eat?

Try to eat unsaturated fats such as vegetable oils, seeds and nuts. Remember that even “good fats” have a lot of calories and thus need to be eaten in moderation.

Try to use skimmed and semi-skimmed milk instead of whole milk and whole-milk products.  

Omega-3 fatty acids are unsaturated fatty acids which cannot be produced by the body itself. This means that they are so-called “essential “fatty acids. Omega-3 fatty acids are supposed to have a range of health benefits such as lowering cholesterol, prevent heart and joint disease and improving learning.

Omega-3 fatty acids may also keep us mentally more stable and may be tried as supplements in people who suffer from mood problems and schizophrenia. They may help prevent relapse in bipolar disorder. However, there is not enough evidence to recommend them as an alternative to antidepressants or mood-stabilizers.

Note: Omega-3 fatty acids taken as supplements may interact with blood thinning drugs. 

Which foods contain omega-3 fatty acids?

Omega-3 fatty acids can be found in oily fish such as cod, salmon and mackerel. They can also be founds in plant sources such as flaxseed and walnuts.

How safe is omega-3 from fish sources?

For most people the benefits will outweigh any concern about possible contamination. Women of childbearing age, or who are expecting a baby, or breastfeeding should not eat more than two portions of oily fish a week.

As recommendations can change, if you are pregnant, you should check with a health professional about how many portions of fish you can eat in a week.

We have produced further information on  omega-3 fatty acids.

What are proteins?

Proteins are made of amino acids. They can be divided in essential amino acids which the body cannot produce itself and non-essential amino acids which the body can manufacture itself.

Complete proteins contain essential amino-acids whereas incomplete proteins do not contain essential amino acids. One gram of protein yields approximately four calories.

What are proteins used for?

Proteins are the main building blocks of the body and make up our muscles. They form enzymes and hormones which are the key to virtually all body functions.

Last but not least amino acids are the basis of our genes and the underlying script of our individual genetic information.

Proteins can also be used as an energy source but this is not very effective and may lead to muscle wasting. This is usually the body’s last resource.


  • Complete proteins are derived from animal products such as meat, fish and milk.
  • Incomplete proteins can be derived from vegetable sources such as grains, pulses and nuts.

What happens if I eat too many proteins?

Problems usually only occur if you eat excessive amounts or if the main organs which process proteins, i.e. the liver and the kidney, do not work properly.

Then the body may get overloaded. Many protein products also contain saturated fat and may lead to weight gain and high cholesterol.

Which proteins should I eat?

Try to eat a varied diet of proteins which provide you with a source of essential amino acids. Even most vegetarian diets are suitable but people eating a strict vegan diet may not get all amino acids they need.

Try to stick to lean protein options such as fish, lean meat, skimmed or semi-skimmed milk or dairy products and whole grains and pulses.

Note that refined wheat and white rice are low in protein because the outer layer of the grain which contains the proteins is removed.

Eating a balanced diet

The UK Food Standards Agency defines a balanced diet as a diet of varied foods. You find examples of recommend foods in the previous respective sections under the question which carbohydrates, fats and proteins should I eat.

The Agency recommends:

  • basing the diet on starchy foods, such as potatoes, cereals, pasta, rice, couscous and bread 
  • five portions of fruit and vegetables
  • meat, poultry, fish, eggs, nuts and pulses as good sources of proteins
  • milk and dairy products as a good source of protein and calcium
  • at least two portions of fish a week
  • cutting down on saturated fat and sugar
  • eat less salt, no more than 6 grams a day for adults and children over 11 years. 

Watching your weight

Some of the recommended foods are not always good options if you want to slim down.

As mentioned above, foods with a low glycaemic index, such as avocados and nuts, are high in calories.

For instance, one medium sized avocado has about 230 calories. That is as much as eating 12 tomatoes.

Avoid processed foods whenever you can but stick to the original food source. For instance, one serving of chips (French fries) (100g) has about 360 calories. This is as much as eating ten medium-sized boiled potatoes (500g).

Drinking well

Many patients with mental health problems always feel thirsty. Part of the problems may be medications leading to a dry mouth.

However drinks can have a lot of calories too.

Low calorie choices include:

  • water
  • tea and coffee (without sugar)
  • skimmed milk (in moderation)
  • “lite” diet soft drinks


  • alcohol
  • sugar-sweetened fizzy drinks
  • juices
  • smoothies

What is it about fruit juice?

It is usually better to eat the whole fruit rather than fruit juice. You may also feel less hungry if you eat the fruits rather than drinking the juice.

One large glass of apple juice (300 ml) contains as many calories as three apples.


It may come as a surprise, but alcohol also has a lot of calories.  One gram of alcohol contains about seven calories. That is nearly as much as one gram of fat which contains about eight calories. One gram of carbohydrate or protein only have about four calories.

Many people like to use supplements but very few people need them to correct a clear-cut deficiency having resulted in poor health.

Most people who take supplements do so in the hope that these carry substantial health benefits, e.g. protecting against cancer, improving the immune system and supporting mental health. However, scientific evidence about the benefits of supplements remains mostly ambiguous with a few exceptions.

Note that supplements are not a substitute for a healthy balanced diet. If you decide to take a supplement do not exceed the recommended daily intake regarded as safe. If you are smoking do not take beta-carotene since the combination may increase your risk of cancer.
Most processes in the body require oxygen. But oxygen can do good as well as harm such as damaging body cells. Antioxidants are substances which neutralize such harmful substances.

They are contained in many vitamins such as vitamin A, C and E and some trace elements such as selenium.

They are contained in many fruits and vegetables such as oranges, strawberries, spinach, tomatoes, carrots and broccoli just to name a few.

Green tea is another good source of antioxidants. Selenium can be found in pasta, bread, eggs, poultry, beef and some fish such as cod.

Calcium is important to keep bones and teeth healthy. This is particularly important in people with mental health problems because some medications increase the risk of osteoporosis.

Calcium may also be helpful to prevent or alleviate premenstrual stress. Good sources of calcium include milk, dairy products and fish such as sardines where the bones are eaten.

Broccoli and kale also contains calcium. However, calcium can only work if it is combined with vitamin D. Good sources of vitamin D include oily fish, some cereals and eggs. Getting out and about and being exposed to sunlight is another good way to get vitamin D (as long as you take care not to burn).

Recently there has been a lot of talk about vitamin D and depression. It seems that people with low levels of vitamin D may be more depressed. But taking a supplement may not make things better after all. We still do not know how the link between depression and low vitamin D levels really works.

We have produced a  leaflet on supplements commonly suggested for mental health problems. You will find further about vitamin E, omega-3 fatty acids, selenium, folic acid and S-adenosylmethionine (SAME).

What is the best diet for schizophrenia?

There is no specific schizophrenia diet but you should eat a balanced varied diet according to the above recommendations.

Ensuring that you eat enough foods rich in omega-3 fatty acids seems a good idea. If you tend to gain weight or have experienced weight gain as a side effect of your medication you should try to eat “good carbs”, i.e. carbohydrates with a low glycaemic index, which are not easily broken down into glucose.

Make sure that you also get calcium in your diet by including dairy products ideally based on skimmed milk to keep the fat intake down.

What is the best diet for mood disorders?

The same principles as above apply. Ensuring enough omega-3 fatty acids may help to keep your mood stable.

If you take lithium you should not drink too many drinks such as tea and coffee since this may reduce your lithium levels. Some vegetables such as artichokes and celery may do the same if eaten in large amounts.

Selenium, folic acid (folate) and tryptophan are substances which have all been implicated in keeping one’s mood stable.

Tryptophan is needed to make serotonin. However, it is not clear how good they are when taken as supplements and you should seek medical advice if you want to use such supplements.

Particularly avoid taking too much selenium as this can lead to poisoning. Instead of using a supplement right away, you may try to eat a balanced diet which contains these substances in sufficient amounts.

Selenium is found in cereals, meats, fish and egg. Selenium is also found in Brazil nuts.

These can be extremely rich in selenium so that one should only eat them occasionally.

Folic acid can be found in cereals and which have been enriched with folic acid. This is also called fortified.

Folic acid is also found in brown rice, leafy green vegetables, peas and broccoli as well as orange juice and bananas. Finally, tryptophan can be found in poultry, meats, some fish such as salmon and halibut and also bananas.

What about chocolate?

Chocolate contains tryptophan but dark chocolate is better than milk chocolate and is even thought to lower cholesterol. However, chocolate of whatever sort is high in calories and should only be eaten in small amounts.

What is the best diet for epilepsy?

A so-called ketogenic diet of help in children with epilepsy which cannot be controlled. A ketogenic is a diet high in fat and low in carbohydrates. The most diet used this type is the Atkins diet. Such a diet can be quite hard to sustain long term though.

The idea of the ketogenic diet is to switch the main fuel of the brain from glucose (sugar) to ketones, which are produced when fat is broken down. Some adults who suffer from uncontrollable epilepsy may also benefit but research findings are much less clear. Seek specialist advice before going on such a diet.

What is the best diet for ADHD?

Again, there are no clear recommendations as research is only just developing in this area. Some research has shown that people with ADHD have lower levels of omega-3 fatty acids or may not be able to tolerate gluten. Gluten is a protein found in wheat, rye and barley.

Many other different food items have been thought to trigger ADHD, but we do not know how well and for whom such diets work. Diets that exclude specific foods thought to be harmful are called elimination diets.

These diets may be also difficult to stick to in the long-term in everyday life. They can be expensive and take time to prepare. Also, people may get tired of them. Others may use them on and off.

One such diet is the Feingold diet which avoids foods containing synthetic food colours and artificial sweeteners, such as aspartame and preservatives. The Feingold diet also cuts out foods containing salicylic acid.

Examples include some apples, red grapes, berries, mushrooms, cucumbers and tomatoes. Some nuts and spices also have high salicylic acid content.

Foods allowed in the Feingold diet include fruits such as banana, grapefruit, pears and pineapples. Other allowed include beef, lamb, plain bread, some cereals, milk, eggs and vitamins that do not contain artificial colouring.

Other elimination diets concern the exclusion of milk, cheese, wheat cereals, egg, chocolate, nuts and citrus fruits. Such diets are also called oligoantigenic diets.

Oligoantigenic means that there are only a few substances that cause adverse reactions and allergies in the body. Foods found in an oligoantigenic diet include rice, turkey, lamb, some vegetables including lettuce, carrots, cauliflower, cabbage and beet. Potatoes, fruits, corn and wheat may be allowed on some days.

In 2011, a Dutch study of 100 children using an oligoantigenic diet showed significant improvement. However, the researchers could only say that the diet helped, but not why the diet helped.

Even the ketogenic diet has been suggested, but findings are only based on animal experiments.

What about grapefruits and grapefruit juice?

Grapefruits are powerful stuff and they can change the way our body metabolizes medication.

Particularly, grapefruits or grapefruit juice can significantly increase the concentration of many medications including some types of antidepressants, antipsychotics and sedatives.

Changes are more likely if grapefruits and grapefruit juice are consumed in large amounts but one cannot even exclude such changes on occasional use.

What about orthomolecular medicine?

Orthomolecular medicine aims at treating or preventing health problems, including mental health problems, through supplements and vitamins.

Vitamins are often recommended in large doses, so-called megavitamins.  Orthomolecular medicine remains controversial and very few studies have been conducted in this area.

These largely suggest that orthomolecular medicine may not be helpful. Large doses of vitamins and supplements may be harmful or even toxic.

That is why the Food Standard Agency has set recommended levels of daily intake for most vitamins and supplements.

Many people think that eating well costs a lot of money. However, eating well can be surprisingly cheap. Here are ten tips which may help you to eat well but cheaply.

  1. Avoid ready meals and take-ways. They are often rich in fat and sugars and may not provide good value for money.
  2. Avoid buying snacks such as crisps, ice creams and sweets apart from the occasional treat.
  3. Shop seasonal fruits and vegetables. For instance, oranges and bananas are winter fruits whereas strawberries and peaches are summer fruits. Broccoli and parsnips are winter vegetables whereas and zucchinis (courgettes) and peppers are summer vegetables. Buying fruits and vegetables out of season can be expensive.
  4. Buy fresh foods such as fruit, vegetables and meats in small amounts and more often since they go off easily.
  5. Avoid canned foods if possible. For instance dried beans and pasta are less expensive than canned beans and processed pasta. Also canned fruits can be more expensive than seasonal fresh fruit but have fewer vitamins.
  6. Avoid sugar-sweetened fizzy drinks and fruit juices. They are often quite expensive. Use water and eat fruit instead.
  7. Compare prices in local shops and supermarkets and take advantage of special offers.
  8. Use “generic” supermarket brands instead of classic brands. They often contain the same ingredients but are cheaper.
  9. Cook and eat together with others and share the costs.
  10. Make a shopping list and plan your food budget every week. If you feel you cannot do this on your own, ask for help. For instance a key worker may be able to help.
NHS Direct


Food Standards Agency – This UK website can be difficult to navigate because of the sheer wealth of information. From the home page, click on the “nutrition” button on the menu. From there you can navigate further. Alternatively, type “recommended daily intake” into the search engine on the homepage.

The Food and Mood Community Interest Company (previously the Food and Mood Project) – This web-based user-led social enterprise founded with a Mind Millennium Award in 1998 sells dietary self-help resources for individuals and groups, including a DIY Food and Mood Workshop pack and The Food and Mood Handbook. – This UK website contains comprehensive information about all aspects of health and ill-health. Go to the home page and click on “health encyclopaedia”. Type “healthy eating” into the search field. This will take you among other things to a quiz to test your healthy eating knowledge and a body mass index calculator. Alternatively go to the health encyclopaedia page and click on “nutrition food and diet”.

NHS choices – Live well. Healthy living for everyone. This website is very helpful to get information on all aspects of healthy eating, ranging from a balanced diet to shopping on a budget, and the evidence behind super foods.

Mayo Clinic: Nutrition and healthy eating – An American website that offers a wealth of information on all aspects of eating and weight control.

MedlinePlus – This is a website run by the US National Institute of Health. The homepage has a search option allowing you to type in different keywords so you can retrieve scientific information you want. Typing the keyword “alternative medicine” or “drug information” will direct you to the relevant sites. OBS: The site can be quite technical and contains lots of medical terms.

Diabetes UK – Excellent website to learn about diabetes and its complications as well as treatments. Go to the home page and click on “guide to diabetes” to access the menu which will guide you to the information you want. Click on “food and recipes” to get new healthy cooking ideas.

Wikipedia – Excellent internet encyclopaedia you can ask almost anything. Most articles are high quality and will refer you to the underlying original work. Go to the main page and type what your are looking for into the search field.

Further reading

Bourre JM (2006) Effects of nutrients (in food) on the structure and function of the nervous system: update on dietary requirements for brain. Part 1: micronutrients. J Nutr Health Aging, 10, 377-385.

Bourre JM (2006) Effects of nutrients (in food) on the structure and function of the nervous system: update on dietary requirements for brain. Part 2: macronutrients. J Nutr Health Aging, 10, 386-399.

Bonfioli E, Berti L, Goss C, et al. (2012) Health promotion lifestyle interventions for weight management in psychosis: a systematic review and meta-analysis of randomised controlled trials. BMC Psychiatry2012, 12,78.

Caemmerer J, Correll CU, Maayan L(2012) Acute and maintenance effects of non-pharmacologic interventions for antipsychotic associated weight gain and metabolic abnormalities: A meta-analytic comparison of randomized controlled trials. Schizophr Res, 140, 159-168.

Faulkner G, Cohn T, Remington G (2007) Interventions to reduce weight gain in schizophrenia. Cochrane Database of Systematic Reviews, Issue 1, Art. No.: CD005148. DOI: 10.1002/14651858.CD005148.pub2.

Feldeisen SE, Tucker KL (2007) Nutritional strategies in the prevention and treatment of metabolic syndrome. Appl Physiol Nutr Metab, 32, 46-60.

Foster-Powell K, Holt SH, Brand-Miller JC (2002) International table of glycemic index and glycemic load values : 2002. Am J Clin Nutr, 76, 5-56.

Freeman MP, Hibbeln JR, Wisner KL, Davis JM, Mischoulon D, Peet M, Keck PE Jr, Marangell LB, Richardson AJ, Lake J, Stoll AL (2006) Omega-3 fatty acids: evidence basis for treatment and future research in psychiatry. J Clin Psychiatry, 67, 1954-1967.

Kjærgaard M, Waterloo K, Wang CE et al (2012). Effect of vitamin D supplement on depression scores in people with low levels of serum 25-hydroxyvitamin D: nested case-control study and randomised clinical trial. Br J Psychiatry, 2012, 201,360-368.

Millichap JG, Yee MM (2012). The diet factor in attention-deficit/hyperactivity disorder. Pediatrics129, 330-337.

Newcomer JW (2007) Metabolic considerations in the use of antipsychotic medications: a review of recent evidence. J Clin Psychiatry, 68 Suppl 1, 20-27.

Reader’s Digest Editors (2001): Foods that harm, foods that heal. An A-Z guide to safe and healthy eating. Reader’s Digest Association Ltd, 2nd edition.

Rizkalla SW, Bellisle F, Slama G (2002) Health benefits of low glycaemic index foods, such as pulses, in diabetic patients and healthy individuals. Br J Nutr, 88 Suppl 3, S255-S262.

Thomas DE, Elliott EJ, Baur L (2007) Low glycaemic index or low glycaemic load diets for overweight and obesity. Cochrane Database of Systematic Reviews 2007, Issue 3. Art. No.: CD005105. DOI: 10.1002/14651858.CD005105.pub2.

Veech RL (2004) The therapeutic implications of ketone bodies: the effects of ketone bodies in pathological conditions: ketosis, ketogenic diet, redox states, insulin resistance, and mitochondrial metabolism. Prostaglandins Leukot Essent Fatty Acids, 70, 309-319.

Werneke U, Taylor D, Sanders TAB, Wessely S (2003) Management of antipsychotic-induced weight gain: A review. Acta Psych Scand, 108, 252-259.

This leaflet was produced by the Royal College of Psychiatrists' Public Education Editorial Board.

  • Series Editor: Dr Philip Timms.
  • Author and Expert: Dr Ursula Werneke

This leaflet reflects the best available evidence at the time of publication.

©  January 2015 Royal College of Psychiatrists