Healthy diet advice and enjoyable eating

What is a healthy diet?

A healthy diet should provide a good balance of nutrients but should ideally also be tasty and enjoyable. Dietary advice within medicine is designed to encourage people to eat a diet which contains the correct balance of nutrients and where portion size is sensible. The complete avoidance of any particular food is rarely recommended. It is rare for doctors to need to give detailed dietary advice but signposting to accurate sources of information is beneficial.

There are specific diets which may require more support to be healthy - for example, vegan diets or gluten- or dairy-free diets. There are many sources of information on these diets which can ensure a healthy balance, despite their limitations.

In January 2023, the government issued guidance on eating well as part of their "All Our Health" strategy.¹ This advised that evidence showed that population intakes of saturated fat, sugar, and salt were above the government recommendations whereas intakes of fibre, fruit, and vegetables, and oily fish were below government recommendations. It was estimated that the average adult was eating between 200 and 300 calories a day more than the recommended level, and that children who were already overweight or living with obesity were eating up to 500 more calories than are required for a healthy body weight.

In the financial year 2020-2021, the NHS was reported to have spent 4.7% of its budget (£6.5 billion) on illnesses related to obesity- and overweight.

The guidance encouraged health professionals to continue to use 'The Eatwell Guide' which was developed by the Department of Health in 2018.² This encourages people to:

• Base meals on starchy foods (such as rice, pasta, potatoes or bread), using wholegrain versions where possible.

• Eat at least 5 portions of fruit and vegetables a day.

• Have some dairy products (or dairy alternatives), choosing lower fat and lower sugar options.

• Eat proteins including fish, beans, pulses, eggs, and meat, with 2 portions of fish a week, 1 of which should be oily fish.

• Choose unsaturated oils and use in small amounts.

• Eat fewer foods containing saturated fats, salt, and sugar.

• Drink at least 6-8 glasses of fluid per day. Any fluid, other than alcohol, counts but fruit juices should be limited to 150ml a day.

Government guidance is of course only valid at the time of publication and may lag behind newer evidence.

A study in 2017 pointed out that most available data is from European and North American populations where nutrition excess is more likely, so their applicability to other populations is unclear. It looked at 135,000 people aged 35-70 years and without cardiovascular disease, from 18 countries in different geographical regions. Higher carbohydrate intake was associated with an increased risk of total mortality, with those eating the most carbohydrates proportionally having a 28% greater risk than those eating the least, although no difference was seen in the risk of cardiovascular disease or cardiovascular disease mortality. Conversely, intake of total fat and each type of fat was associated with a lower risk of total mortality, while a higher saturated fat intake was associated with lower risk of stroke.³

A 2021 study from Australia looked at women between the ages of 50 and 55 and concluded that moderate carbohydrate intake (41.0%–44.3% of their total energy intake) was associated with the lowest risk of CVD, without an effect on total mortality. Increasing saturated fat intake was not associated with CVD or mortality and instead correlated with lower rates of diabetes, hypertension, and obesity. ⁴

A 2023 meta-analysis showed that increased consumption of dietary carbohydrate intake is associated with increased risk of cardiovascular disease, stroke, and all-cause mortality.⁵

A more recent study from Korea in 2024 suggested that reducing carbohydrate intake and increasing the intake of fat and protein had beneficial effects on both longevity and cardiovascular health.⁶

These studies go against the prevailing wisdom of the last few decades which has encouraged lower fat intakes and higher carbohydrate intakes and suggests that dietary sugar is more harmful than dietary fats, both in terms of ill-health and in terms of risks of obesity.

More recently there has been a focus on the risks of ultra-processed foods (UPFs). Diets in the West are increasingly dependent on UPFs. Studies are beginning to demonstrate that these are causing harm, independent of the fat and sugar content of the foods. A meta-analysis in 2023 (although considered to be of low quality) suggested that total UPF consumption was associated with higher risk of diabetes, hypertension, dyslipidemia, and obesity.⁷A meta-analysis in 2024, with some higher quality evidence, found that greater exposure to ultra-processed food was associated with a higher risk of adverse health outcomes, especially cardiometabolic, common mental disorder, and mortality outcomes.⁸A further meta-analysis in 2024 concluded that "high UPF consumption is associated with an increased risk of a variety of chronic diseases and mental health disorders. At present, not a single study reported an association between UPF intake and a beneficial health outcome. These findings suggest that dietary patterns with low consumption of UPFs may render broad public health benefits."⁹

There is generally little evidence that supplements replace health dietary intake of vitamins, minerals, and other nutrients. An unhealthy diet is not offset by taking dietary supplements.¹⁰

Eat a variety of different foods

No single food provides all the nutrients required for the body to stay healthy.

Eat the right amount to be a healthy weight

Women tend to need less energy than men and older adults tend to need less energy than adolescents and young adults.¹¹

Regular aerobic exercise is a very important part of weight control.

Eating breakfast every day has previously been thought to be beneficial in helping people control their weight, assumed to be due to decreasing hunger for unhealthy foods later in the day, but more recent studies have called this into question, suggesting little to no benefit in adults¹²¹³but with some evidence that eating breakfast reduces obesity in children and adolescents.¹⁴

Eat starch, fibre and wholegrain foods

Eating foods rich in fibre, particularly from fruit, cereals, and vegetables, resulted in reduced risks of cardiovascular disease.¹⁵

Wholegrain foods contain more fibre and other nutrients than white or refined starchy foods and include wholemeal and wholegrain bread, pitta and chapati, wholewheat pasta and brown rice, and wholegrain breakfast cereals.

Wholegrain cereal foods are particularly rich in insoluble fibre, which helps to prevent constipation.

Soluble fibre in fruit, pulses (beans, lentils and chickpeas), and vegetables can help to reduce the amount of cholesterol in the blood.¹⁶Increasing fibre reduces the risk of heart disease, diabetes and colorectal cancer.¹⁷ Higher dietary fibre has also been shown to reduce the risk of colorectal, stomach, oesophageal, breast, endometrial, ovarian, prostate, pancreatic, and renal cell cancers.¹⁸High dietary fibre intake has been shown to reduce all-cause mortality.¹⁹

There is not enough evidence at present to suggest that fibre supplements are as effective as increased dietary fibre.

Eat plenty of fresh fruit and vegetables

There is evidence that a diet rich in fruit and vegetables reduces the risk of developing coronary heart disease and some cancers.²⁰

The UK government recommends eating at least five portions of fruit and vegetables daily. The World Health Organization (WHO) recommends 400 g a day. Different countries have different guidelines. ²¹ Try to eat a wide variety of different fruits and vegetables.

One portion of fruit or vegetables weighs about 80 g. Some examples are:

• An apple, banana, pear, orange, or other similar-sized fruit.

• Two plums or similar-sized fruit.

• A grapefruit or avocado.

• A slice of large fruit, such as melon or pineapple.

• Three heaped tablespoons of vegetables (raw, cooked, frozen, or tinned).

• Three heaped tablespoons of fruit salad (fresh or tinned in fruit juice) or stewed fruit.

• A heaped tablespoon of dried fruit (such as raisins and apricots).

• A dessert bowl of salad.

• A glass (150 ml) of fruit juice.

• A cupful of grapes, cherries or berries.

Fish²²

Try to eat at least two portions of fish (fresh, frozen or canned) a week, including a portion of oily fish. This includes oily fish like salmon, mackerel, trout, herring, fresh tuna, sardines, pilchards, and eel. Smoked fish can be high in salt.

With shark, swordfish, and marlin, don't have more than one portion a week because of the high levels of mercury.

Protein

Protein-rich foods include meat, fish, eggs, and pulses.

There is inconclusive evidence on whether high egg consumption increases CVD mortality and morbidity.²³

Poultry such as chicken and turkey contain less fat than meats such as pork and beef, although red meat is a richer source of iron.

Red meat and processed meat should be eaten sparingly due to the increased risks of cancer (particularly colorectal cancer) associated with increased intake. Red meat consumption has been shown to increase the risks of colorectal cancer.²⁴

Processed and red meats were shown to increase the risks of colorectal cancer in a large UK study published in 2020. Those eating 79 g per day on average had a 32% increased risk of bowel cancer compared to people eating less than 11 g of processed and red meat daily.²⁵

A meta-analysis showed that high intake of red meat increased the risks of breast cancer, endometrial cancer, colorectal cancer, colon cancer, rectal cancer, lung cancer, and hepatocellular carcinoma, and that a higher intake of processed meat increased the risks of breast, colorectal, colon, rectal, and lung cancers. This effect on non-GI cancers has not been fully replicated in other studies to date.²⁶

Minerals and vitamins

A healthy diet should contain adequate quantities of all essential vitamins and minerals. A healthy level of most vitamins and minerals will be found in a varied diet rich in fruits and vegetables, protein and dairy products. Many UK breakfast cereals have additional vitamins added to them.

Avoid too many foods that contain a lot of fat

Foods high in saturated fat include meat pies, sausages, burgers, meat with visible white fat, hard cheese, butter and lard, pastry, cakes and biscuits, chocolate, cream, soured cream and crème fraîche, coconut oil, coconut cream, and palm oil.

Avoid frequent sugary foods and drinks¹⁷

Recommendations suggest that free sugars (found in soft drinks, yoghurts, cakes, and biscuits, etc) should not account for more than 5% of total dietary energy.

Sugar causes tooth decay, and sugary foods tend to be high in calories, contributing to obesity

Avoid excessive salt²⁷

Salt intake contributes to high blood pressure. Government guidelines tailor their advice to children and adults. Children between the ages of 1-18 years should have no more than 2-6 g of salt daily, depending on age. People over the age of 18 should have no more than 6 g of salt a day. Younger children should have even less.

75% of the salt we eat comes from processed food - for example, some breakfast cereals, ready meals, meat products, soups, sauces, bread, and biscuits.

Other flavourings can be added to food to make it tasty in place of salt, such as garlic, herbs, or spices.

Ensure adequate fluid intake²⁸

In climates such as that of the UK, we should drink approximately 1.2 litres (6 to 8 glasses) of fluid every day to stop us becoming dehydrated. In hotter climates the body needs more than this.

Excessive amounts of caffeine-containing drinks (for example, tea, coffee, and cola) should be avoided because of their diuretic effect.

Keep alcohol consumption within recommended limits

Alcohol is also high in calories, so cutting down helps to control weight as well as avoiding other alcohol-related problems. Men and women should not drink more than 14 units of alcohol a week. This should be spread evenly over the week and heavy drinking sessions once or twice a week should be avoided.

A unit is:

• Between a third and a half pint of standard-strength (3-5%) beer, lager or cider.

• A pub measure of spirit.

• Approximately 90 ml of wine. A 175 ml glass of wine contains just over 2 units and a 250 ml glass contains 3 units.

Alcohol intake should be spread throughout the week. Try to have at least two alcohol-free days each week and avoid binge drinking (more than 6 units for women or 8 units for men).