Too much fat in your diet, especially saturated fats, can raise your cholesterol, which increases the risk of heart disease.

Why we need some fat

A small amount of fat is an essential part of a healthy, balanced diet. Fat is a source of essential fatty acids, which the body cannot make itself.

Fat helps the body absorb vitamin A, vitamin D and vitamin E. These vitamins are fat-soluble, which means they can only be absorbed with the help of fats.

Any fat that's not used by your body's cells or turned into energy is converted into body fat. Likewise, unused carbohydrates and proteins are also converted into body fat.

All types of fat are high in energy. A gram of fat, whether it's saturated or unsaturated, provides 9kcal (37kJ) of energy compared with 4kcal (17kJ) for carbohydrate and protein.

The main types of fat found in food are:

• saturated fats
• unsaturated fats

Most fats and oils contain both saturated and unsaturated fats in different proportions.

As part of a healthy diet, you should try to cut down on foods and drinks that are high in saturated fats and trans fats and replace some of them with unsaturated fats.

Saturated fats

Saturated fats are found in many foods, both sweet and savoury.

Most of them come from animal sources, including meat and dairy products, as well as some plant foods, such as palm oil and coconut oil.

Foods high in saturated fatfatty cuts of meat :meat products, including sausages and pies

• butter, ghee, and lard
• cheese, especially hard cheese like cheddar
• cream, soured cream and ice cream
• some savoury snacks, like cheese crackers and some popcorns
• chocolate confectionery
• biscuits, cakes, and pastries
• palm oil
• coconut oil and coconut cream

Cholesterol and saturated fats

Cholesterol is a fatty substance that's mostly made by the body in the liver.

It's carried in the blood as:

• low-density lipoprotein (LDL)
• high-density lipoprotein (HDL)

Eating too much saturated fats in your diet can raise "bad" LDL cholesterol in your blood, which can increase the risk of heart disease and stroke.

"Good" HDL cholesterol has a positive effect by taking cholesterol from parts of the body where there's too much of it to the liver, where it's disposed of.

Saturated fat guidelines

Most people in the UK eat too much saturated fats.

The government recommends that:

• men should not eat more than 30g of saturated fat a day
• women should not eat more than 20g of saturated fat a day
• children should have less
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Trans fats are found naturally at low levels in some foods, such as meat and dairy products.

They can also be found in partially hydrogenated vegetable oil. Hydrogenated vegetable oil must be declared on a food's ingredients list if it's been included.

Like saturated fats, trans fats can raise cholesterol levels in the blood.

The government recommends that:

• adults should not have more than about 5g of trans fats a day

But most people in the UK do not eat a lot of trans fats. On average, we eat about half the recommended maximum.

Most of the supermarkets in the UK have removed partially hydrogenated vegetable oil from all their own-brand products.

People in the UK tend to eat a lot more saturated fats than trans fats. This means that when you're looking at the amount of fat in your diet, it's more important to focus on reducing the amount of saturated fats.

Unsaturated fats

If you want to reduce your risk of heart disease, it's best to reduce your overall fat intake and swap saturated fats for unsaturated fats.

There's good evidence that replacing saturated fats with some unsaturated fats can help to lower your cholesterol level.

Mostly found in oils from plants and fish, unsaturated fats can be either monounsaturated or polyunsaturated.

Monounsaturated fats

Monounsaturated fats help protect your heart by maintaining levels of "good" HDL cholesterol while reducing levels of "bad" LDL cholesterol in your blood.

Monounsaturated fats are found in:

• olive oil, rapeseed oil and spreads made from these oils
• avocados
• some nuts, such as almonds, brazils, and peanuts

Polyunsaturated fats

Polyunsaturated fats can also help lower the level of "bad" LDL cholesterol in your blood.

There are 2 main types of polyunsaturated fats: omega-3 and omega-6.

Some types of omega-3 and omega-6 fats cannot be made by your body, which means it's essential to include small amounts of them in your diet.

Omega-6 fats are found in vegetable oils, such as:

• rapeseed
• corn
• sunflower
• some nuts

Omega-3 fats are found in oily fish, such as:

• kippers
• herring
• trout
• sardines
• salmon
• mackerel

Most people get enough omega-6 in their diet, but it's recommended to have more omega-3 by eating at least 2 portions of fish each week, with 1 portion being an oily fish.