Food for health: how diet can prevent disease

What we eat does so much more than just fuel our bodies, it plays a big role in how we feel, both now and in the long run. More and more, research is showing just how closely our everyday food choices are linked to our long-term health, including the risk of chronic conditions like heart disease, type 2 diabetes, and some cancers.

But here’s the encouraging part: many of these health issues are largely preventable, and even small changes can make a big difference. We now know more than ever about how food can support not just a longer life, but a more energetic, vibrant one.

In this guide, we’ll explore diet-related diseases and the risks of certain eating habits. We’ll also offer up some easy-to-implement tips for boosting your health through food. 

What are diet-related diseases?

"An apple a day keeps the doctor away." Old sayings like this show we’ve known for a long time that food plays a vital role in keeping us healthy. Today, scientists know much more about how poor diets can lead to health problems. If our bodies don’t get the right balance of nutrients, it can affect the health of our hearts, our digestive systems, and cause other health issues. 

Diet-related diseases are long-term health conditions that don’t spread from person to person, they’re not like picking up a cold from a friend. But even though they develop quietly over time, their impact can be deeply felt. 

Living with these kinds of illnesses can take a real toll, not just on your body but on your mood, energy, and ability to enjoy the things you love. Worldwide, unhealthy diets are responsible for 11 million deaths each year and are reducing the quality of life for 255 million people.¹

Common diet-related diseases in Europe include heart disease, type 2 diabetes, certain cancers (particularly colorectal cancer), Alzheimer’s disease, dementia, and stroke.

Percentage of total deaths attributable to dietary risks (2021)

This map shows the percentage of total deaths in 2021 that can be attributed to dietary risks. Dietary risks include a diet low in fruits and vegetables, or a diet high in processed meat or sugary beverages.

Data source: Global Burden of Disease.

How food affects your health

Many of us are living longer lives than our ancestors thanks to modern medicine, poverty reduction, and safer work environments. But we’re not necessarily living healthier lives. Poor diets are a major factor, alongside issues like lack of physical activity, smoking, and the stresses of modern life.

However, let’s be absolutely clear: it’s fine to treat yourself sometimes. Food should bring joy to your life. If your best friend lovingly bakes you a bright pink birthday cake, you should probably have a slice! What we’re talking about here is the impact of frequently eating unhealthy food over long periods, not the occasional treat.

It’s also clear that genetics plays a role in our health. Many people know a healthy neighbour in their nineties, despite seeming to eat, drink and do whatever they want. These people are probably just very lucky when it comes to their genes. But for most of us, eating healthy food and getting regular exercise really helps us stay healthy.

Eat well to stay well

Health experts worldwide recommend a balanced diet. Making sure you include all five of these major food groups each day is a great way to support long-term health. A nutritious diet can reduce your risks of multiple diseases – and provide you with the fuel for an active lifestyle.

Food group	Why we need them2
Fruit and vegetables	Contains:  - Vitamins and minerals that your body needs to function properly and maintain health. - Fibre which helps with digestion. It reduces the risk of heart disease, stroke, and some cancers, and contributes to overall health. - Colourful fruit and veg are rich in “phytonutrients”, which may help reduce the risk of chronic diseases and keep your tummy happy. Have at least five portions a day, eating both fruit and vegetables Did you know? Eating a Mediterranean diet – rich in fruit, vegetables and wholegrains – may also lower your risk of developing dementia.3
Starchy foods like potatoes, bread and pasta	Contains: - Digestible carbohydrates, our body’s main fuel source. - Fibre. Choose fibre-rich carbs like wholegrain bread and oats, which aid digestion and leave you feeling full for longer. Did you know? Most European adults are falling short of the recommended minimum 30g of fiber per day.4
Dairy and alternatives	Contains:  - Protein, essential for growth, repair, and fighting disease. - Calcium, essential for healthy bones and teeth.  Did you know? Some yoghurts and cheeses contain live bacteria and yeasts that can help support a healthy digestive system.
Fish, meat, beans, pulses, eggs, lentils, tofu and other meat alternatives	Contains:  - Protein - Oily fish – such as salmon, mackerel, and sardines – are also rich in a nutrient called omega-3 fatty acids. They support your brain and heart health, and are also found in many nuts and seeds.  Did you know? In several Asian countries seaweed is a healthy source of protein. For instance, the nori leaves used to make sushi.
Oils, spreads, seeds	Contains - Fats. Small quantities of fats are important for energy storage, cell function, and help the body absorb important vitamins. Did you know? Olive oil is an unsaturated fat packed with healthy nutrients. Unsaturated fats are usually a healthier option than the saturated fats typically found in solid foods like butter, fatty meat and cheese.

Don't forget water! Women should aim for 9 cups a day, and men 13. Drink even more if you're active or unwell, or it's especially warm. Your body needs water to function. Every cell in our bodies relies on it, and it helps flush out toxins. Dehydration can cause dizziness and poor focus, and long-term lack of water may raise the risk of heart failure, diabetes, lung disease, and dementia.

Small changes, big impact: foods to cut back on

Some ingredients make meals tasty, enjoyable, and satisfying, but it’s important to be mindful of how much we consume. For the following ingredients, moderation is key to keeping our health on track.

Salt	Too much salt raises blood pressure, increasing the risk of heart attacks and strokes. Limit: no more than 6g per day, about 1 teaspoon. This includes salt already in foods like bread, cheese and sauces.2
Sugar	Added sugars cause sharp spikes in blood sugar, which over time can stress the body and raise disease risk. Limit: around 25g daily (6 teaspoons).
Saturated fats	Linked to heart disease and inflammation; often found in fried foods and some baked goods.  Limit: an average man should eat no more than 30g of saturated fat a day, 20 g for the average woman.2 Avoid trans fats (check labels for “partially hydrogenated oils.”)

Learn more in Sugar 101: What It Is, Why It Matters & Healthier Alternatives

Many packaged foods are designed to be quick, tasty, and easy – and when life gets busy, that’s a big help. But the downside is that these ultra-processed foods often offer very little real nutrition. Instead, they tend to be packed with added sugar, salt, unhealthy fats, and a long list of artificial additives to boost flavour and shelf life. The result? Food that’s quick and pleasurable in the moment but may leave your body missing what it really needs, while giving you more calories than you need.

Did you know? All of the following are ultra-processed foods. - Breakfast cereals and bars - Crisps - Soft drinks and sweetened beverages - Instant noodles and soups - Reconstituted meat products like chicken nuggets - Pre-prepared frozen meals

In many European countries, ultra-processed foods (UPFs) are everywhere. At the top of the list are the UK and Germany, where roughly half of all household food purchases are ultra-processed.⁵

Experts are learning more about UPFs and health all the time. We now know that these products can leave you feeling less full than whole foods, making it easier to overeat and gain weight.6 High consumption of UPFs has been linked with a wide range of health risks, from obesity to heart disease and cancer.⁶ 

In the coming years, we’re likely to learn much more about the dangers of specific ingredients, or combinations of ingredients. Connections between these foods and mental health are also becoming clearer, where studies identify links between UPFs and symptoms of depression and anxiety.⁷

Learn more in Good mood food: the link between what you eat and how you feel

Fancy a FoodUnfolded challenge?  "Decode the Label" Pick one packaged food this week and really read its nutritional label. Can you spot hidden sugars, salts, saturated fats, or 20-syllable additives? Even foods with packaging that make them seem healthy can be ultra-processed. Learning to decode nutrition labels helps you spot hidden sugars, salts, unhealthy fats, and additives, making it easier to choose foods that support your health.

Simple food swaps for a healthier diet

Despite what some people say, healthy food doesn’t have to be boring. There are plenty of options that are yummy, colourful and full of amazing textures. With just a few small changes, you can enjoy food that not only tastes amazing but also supports your wellbeing for the long run. It’s fun to experiment, and it doesn’t have to be a drag to prepare. Try some of these simple swaps:

Meal	Less healthy option	Simple swap
Breakfast	Sugary cereals	Greek yoghurt with oats & berries
Morning snack	Biscuits or cereal bar	Banana and a handful of unsalted nuts and seeds
Lunch	White bread sandwich with salami & cheese slices	Wholegrain wrap with hummus and mixed roasted veggies
Afternoon snack	Crisps or chocolate bar	Rice cake with peanut butter or cottage cheese
Dinner	Frozen pizza or pasta ready meal	Pizza base topped with your favourite veggies and modest amount of cheese

Top tip: Start small. Swapping just one meal or snack a day will help you shift to a healthier diet.