Macronutrients

their role in the body

Carbohydrates

Carbohydrates are a group of organic compounds which supply
energy to the body and are found in fruits, grains, vegetables, and
milk products; they are made up from:provide the body with energy.

  • Simple carbohydrates (sugars): are easily digested and absorbed
    in the small intestines to provide quick release energy. Some
    sugars occur naturally in dairy and fruits however, most sources of
    sugars in Europe contain added sugars (often called free sugars)
    e.g. table sugar, honey, syrup, soft drinks, confectionary, jam,
    biscuits, cakes, some savoury foods e.g. ketchup.
  • Complex carbohydrates which include:
    Starch: digested and absorbed in the small
    intestines to provide slow release energy.
    Fibre: not digested or absorbed in the small
    intestine; passes into the colon. Fibre comes in
    several forms which have various beneficial effects
    depending on properties such as solubility, viscosity
    and fermentability.

Carbohydrates are a group of organic compounds which supply
Carbohydrates provide 4 kcal/g energy and make up around 40-60% of the energy in most diets; they are essential
for good health. It is best to consume starchy and wholegrain carbohydrates which provide slow release energy
and fibre. Free sugars should be minimised in the diet as they are not essential for good health. For the majority of
people, this means increasing consumption of starchy and wholegrain carbohydrates and reducing free sugars.milk products; they are made up from:provide the body with energy.

Did you know?

Carbohydrates are the only fuel source metabolised fast enough to support hard exercise; also, the brain is the only organ in the body dependent on carbohydrate.

Carbohydrates provide 4 kcal/g energy and make up around 40-60% of the energy in most diets; they are essential for good health. It is best to consume starchy and wholegrain carbohydrates which provide slow release energy and fibre. Free sugars should be minimised in the diet as they are not essential for good health. For the majority of people, this means increasing consumption of starchy and wholegrain carbohydrates and reducing free sugars.

Be aware!

Alcohol is made from sugar and contains 7 kcal/g energy with no nutritional benefit!

Protein

Proteins are nitrogenous organic compounds composed of long chains of molecules called amino acids. They are the “work horses” of our body and ensure many biological functions: they take part inmetabolism, growth, repair, and are essential in maintaining good health in general. Haemoglobin (transporting iron and oxygen in our blood), enzymes, antibodies, many hormones (such as insulin), are only a few examples of the many proteins present in our body. They are also important structural components of body tissues e.g. muscle, hair, bone, skin, etc.

Most foods contain protein. Animal proteins are “complete” and supply all the essential amino acids we need, so are of higher nutritional value than plant proteins. As a result, older adults are recommended to consume good quality animal proteins, low in saturated fat e.g. lean red meat, poultry, fish, eggs and low-fat dairy (e.g. milk and cheese). Plant proteins are “incomplete”; they do not supply all essential amino acids individually but combining
the right plant proteins e.g. legumes or pulses with cereals or nuts, can provide all essential amino acids.

Protein has 4 kcal/g and provides around 10-15% of dietary energy; it is the second most abundant compound in the body, after water. On average, protein is contained in the body in the following amounts: muscle (43%), skin (15%), blood (16%). As the main protein stores in our body, muscle can be mobilised as a last resort to provide energy if required, leading to a decrease in muscle mass.

Did you know?

The human body has around 100,000 different proteins from different combinations of 21 amino acids.

Fats

are important nutrients that supply energy (9 Kcal/g), are part of cell membranes, and can regulate many processes in the body; they are particularly important for the absorption of fat-soluble vitamins (A, D, E, K). Fats should form part of a balanced, healthy diet however, the amount and type of fats eaten is important to good

Trans fats are a form of unsaturated fat; some occur
naturally in meats and dairy however, most are artificially produced by hydrogenation creating semi-solid oils. Trans fats have been associated with negative health effects but have mostly been removed from food products in the UK since 2012.

Saturated fats are generally found in higher amounts in animal fats and are unhealthy in high quantities; they can elevate blood cholesterol and increase the risk of heart disease. Plant and dairy sources are considered better for you than meat sources.

Did you know?

An average adult has approximately 50 billion fat cells!

Unsaturated fats are healthier fats found in higher amounts in plant sources; swapping saturated fats for unsaturated fats can help lower blood cholesterol. Monounsaturated fats are healthier than saturated fats and Omega-6 polyunsaturated fats (PUFAs) however, some PUFAs are essential as they cannot be synthesised in the body, but are required for many body processes. Omega-3 and Omega-6 fats can compete in our body and have opposing effects on several biological processes, including inflammation, blood fluidity and the elasticity of our blood vessels. A ratio of 4:1 (Omega-6:Omega-3) is normally recommended in the diet however, some research suggests the ratio should be lower (as low as 1:1). The ratio reported being consumed in Europe is generally too
high (approximately 15:1), underlining the need to consume more Omega-3 and less Omega-6.

Macronutrient recommendations

are important nutrients that supply energy (9 Kcal/g), are part of cell membranes, and can regulate many processes in the body; they are particularly important for the absorption of fat-soluble vitamins (A, D, E, K). Fats should form part of a balanced, healthy diet however, the amount and type of fats eaten is important to good

Trans fats are a form of unsaturated fat; some occur
naturally in meats and dairy however, most are artificially produced by hydrogenation creating semi-solid oils. Trans fats have been associated with negative health effects but have mostly been removed from food products in the UK since 2012.

Saturated fats are generally found in higher amounts in animal fats and are unhealthy in high quantities; they can elevate blood cholesterol and increase the risk of heart disease. Plant and dairy sources are considered better for you than meat sources.