Macronutrients and Healthy Eating

In this activity, we will look at the components of our diets: macro and micronutrients, and the balance of healthy and less healthy components.

What are Macronutrients?

Macronutrients are the nutrients we need in larger quantities that provide us with energy, including 1) carbohydrates (4 kcal per gram), 2) proteins (4 kcal per gram), and 3) fat (9 kcal per gram).

Carbohydrates

Carbohydrates provide energy for the body. It can be found in all starchy foods (e.g. bread, potatoes, pasta), fruits, vegetables and milk products. There are three different types of carbohydrates found in food: starch, sugar and fibre.

• Starch is white and solid at room temperature and does not dissolve in cold water. Most plants, such as rice and potatoes, store their energy as starch. Your body digests starch to make glucose, which provides a slow and steady release of energy throughout the day.
• Sugars are soluble carbohydrates. Most foods contain several different types of sugar. The types of sugar that need to be controlled are called free sugars, which are sugars that are added to food or drinks. This is different for foods such as fruit and vegetables which naturally contain sugar within their structure. These foods do not need to be cut down, as they also contain a lot of useful nutrients.
• Fibre is found in the cell walls of foods that come from plants. It is important for our health as it helps our digestive health and reduces the risk of constipation. Good sources of fibre include fruit, vegetables, wholegrain bread and pasta, beans and lentils.

Proteins

Proteins provide amino acids and energy, which is essential for our growth and maintenance of good health. It can be found in animal derived products (such as meat, eggs and dairy foods) and also other sources (such as nuts, pulses and soya products).

Fat

Fat provides essential fatty acids and energy. A small amount of fat, which our body cannot make itself, is an important part of a healthy diet. Fat is helping our body to absorb fat-soluble vitamins (vitamin A, E and D). The main types of fat found in foods are saturated fats and unsaturated fats. Eating a diet high in saturated fat is associated with a raised level of “bad” LDL cholesterol, which is linked to an increased risk of cardiovascular disease.

• Saturated fats are found in many foods, including animal sources (such as meat and dairy products), some plant foods (such as coconut oil and palm oil), as well as sweet and savoury foods (such as chocolate confectionery and cakes).
• Unsaturated fats include monounsaturated fat and polyunsaturated fat, which is found in oils from plants and fish. Mounting evidence shows that replacing saturated fats with some unsaturated fat can help to lower the overall cholesterol level.

In the UK, Dietary Reference Values for carbohydrates and fats are 50 % and ‘not more than 35 %’ of the total daily food energy, respectively. The Reference Nutrient Intake for proteins is set at 0.75 g per kilogram bodyweight per day in adults. You can find the UK Dietary Reference Values in the See Also section below.

Author: Dr. Jing Guo