Dietary fats: what’s the difference between them and why it matters

Why do I need to eat fat?

Fats are an important part of your diet. Below are some important reasons why you should include them in your diet.

• Your body needs some fat to help absorb certain vitamins in food that are important for your health – such as vitamin A and vitamin D
• Your body needs fat to help build the membranes that surround and protect your cells
• Fats are also needed to make hormones which regulate bodily processes.
• Fats provide your body with a source of energy.

What are the different types of fats?

There are many different types of fats – and some can be better for your health than others.

Saturated fat

A diet high in saturated fat can lead to increased levels of low-density lipoprotein (LDL) cholesterol, which is a key risk factor for heart and circulatory disease. Saturated fats are found in many everyday foods, particularly from animal sources including meat, cheese, butter, and full-fat dairy products. Saturated fat is also found in foods made using these items, such as:

• pastries and croissants
• pies
• samosas
• cakes and biscuits

Saturated fat can also be found in plant-based fats including palm oil and coconut oil. Most people in the UK eat more saturated fat than is recommended. Women should aim for no more than 20g of saturated fat a day, and men no more than 30g a day.

Trans fat

Trans fats can have a similar effect on the body to saturated fats by increasing cholesterol levels in the blood. They are naturally found in small amounts in meat and dairy products. They are also found in products that contain partially hydrogenated vegetable oils. Checking ingredient labels can help you identify these fats.

Current recommendations suggest that adults should limit their intake to no more than 5g of trans fat per day.

Unsaturated fats

Unsaturated fats are considered to be a healthier type of fat and are commonly found in plant-based foods. There are two types: monosaturated and polyunsaturated fats.

Monounsaturated fats are found in:

• olive oil
• rapeseed oil
• almonds
• avocado

Polyunsaturated fats are found in:

• sunflower oil
• vegetable oil
• soya oil
• walnuts
• sunflower seeds
• oily fish such as salmon, mackerel, and sardines

Replacing foods high in saturated fat with sources of unsaturated fats can help to lower cholesterol levels and support heart health.

What fats should I avoid to improve my heart health?

When it comes to fats, it’s not just the type of fat, but also how much you eat and which food source it comes from. Regularly eating too much saturated fat can increase cholesterol levels in the blood, which may raise your risk of heart disease and stroke.

However, some foods that contain saturated fat, such as yoghurt and other dairy products, can also provide other important nutrients like protein and calcium. These foods can still be enjoyed as part of a healthy balanced diet. Lower-fat options are also readily available.

A simple way to improve the balance of fats in your diet is to eat fewer takeaways and highly processed foods, which are often higher in saturated and trans fats. Cooking more meals at home using fresh ingredients can help you make healthier choices while still enjoying a varied and nutritious diet.

Are there certain fats I should eat more of?

Unsaturated fats are considered a healthier choice and are an important part of a balanced diet. Two key types of unsaturated fat are omega-3 and omega-6 fatty acids. These are known as essential fatty acids because the body cannot produce enough of them on its own, so they need to be obtained through food. Unsaturated fats play important roles in cell function, growth, and brain health. Omega-3 fats are found in oily fish, walnuts, and linseeds, while omega-6 fats are found in nuts, seeds and vegetable oils.

Including more unsaturated fats instead of saturated fats may help improve cholesterol levels by lowering low-density lipoprotein (LDL) cholesterol and supporting healthy levels of high-density lipoprotein (HDL) cholesterol. This can contribute to better heart health and may help reduce the risk of cardiovascular disease.

The Mediterranean diet is often regarded as one of the healthiest dietary patterns in the world. It emphasises foods rich in unsaturated fats, such as olive oil, nuts, seeds, and oily fish, while limiting foods high in saturated fat. This balance is thought to be one of the reasons why the Mediterranean diet is associated with positive health outcomes.

How much fat per day should I eat?

Fat is a concentrated source of energy, providing more than twice as much energy per gram as protein or carbohydrate. Because of this, it's important to be mindful of portion sizes and overall intake. Regularly consuming more energy than your body needs can contribute to weight gain. Over time, this may increase the risk of health conditions such as type 2 diabetes, high blood pressure and heart disease.

Most people in the UK eat more than the recommended amount of fat. According to guidelines, each day:

• men should have no more than 95g of fat (of which 30g is saturated fat)
• woman should have no more than 70g of fat (of which 20g is saturated fat)

However, it’s not just the amount of fat you eat that matters. The type of fat you choose can have an even greater impact on your heart health.

How can I identify foods high in fat?

One of the easiest ways to check how much fat a food contains is to look at the nutrition label. This will show the amount of total fat and saturated fat per 100g and per serving. As a guide, foods containing 3g of fat or less per 100g are considered low in fat. Foods containing 1.5g of saturated fat or less per 100g are considered low in saturated fat.

Many food products also use traffic light labelling to help you make informed choices. These labels use red, amber and green colours to show whether a food is high, medium, or low in fat, saturated fat, sugar, salt, and calories. A green label indicates a lower amount, making it quick and easy to compare products when shopping.

Practical tips to improve balance of fats in your diet

Here are some simple ways to achieve a good balance of fats in your diet.

• Choose lean cuts of meat or plant-based alternatives, such as beans, lentils, or tofu. If you eat meat, trim away any visible fat where possible.
• Opt for cooking methods that require little or no added fat such as grilling, steaming, baking, or air-frying.
• When using fats for cooking or dressing foods, use an unsaturated fat, such as olive oil or rapeseed oil.
• Try using an oil spray when cooking, as this can help reduce the amount of oil used while still adding flavour and preventing foods from sticking.
• Aim to eat two portions of fish each week. This should include at least one portion of oily fish, such as mackerel, salmon, or sardines.
• If you’re vegetarian or vegan, sources of omega-3 include walnuts, linseeds, chia seeds, and soya products (such as beans, milk, and tofu). Omega 3 supplements are generally not recommended, and you should speak with a dietitian before taking one.
• For snacks, try a small handful of unsalted nuts instead of foods such as crisps, biscuits, or pastries.

While it can be helpful to be mindful of the amount of saturated fat you eat, there is no need to avoid fat altogether. Different types of fat have different effects on health, and unsaturated fats can be a valuable part of your diet.

Following a Mediterranean-style eating pattern can be a useful way to incorporate these changes into your diet.

It’s also important to remember that reducing saturated fat is just one way of achieving a healthy, balanced diet. The overall pattern of what you eat, including plenty of vegetables, fruit, wholegrains, legumes, and other nutrient-rich foods, also plays an important role for your long-term health.