Macronutrients
Total dietary energy intake is comprised of varying proportions of macronutrients – these are carbohydrate, fat and protein.
How much carbohydrate should I eat?
Nutrition experts recommend that adults and children aged two years and above obtain approximately 50% of their daily calories from a variety of carbohydrate sources1. The bulk of these should come from starch-rich foods including bread, rice, pasta and other wholegrain and high fibre sources, and smaller amounts may come from sugars which are found naturally in foods such as fruit and vegetables.
The role of fat in a healthy, balanced diet
UK dietary guidelines advise approximately 35% of total daily calories from fats, with no more than 11% from saturated fats2.
Did You Know?: sugar provides less than half the calories provided by fat (4 calories per gram of sugar compared to 9 calories per gram of fat)
Fats can be divided into three types, depending on the fatty acids they contain:
- Saturated Fatty Acids (SFAs)
- Monounsaturated Fatty Acids (MUFAs)
- Polyunsaturated Fatty Acids (PUFAs)
Some dietary fat is essential as it is required for energy production and to supply essential fatty acids and transport fat-soluble vitamins around the body (vitamins A, D, E and K). Avoiding all foods that contain fat reduces the variety of foods eaten and can lead to nutritional deficiencies, but it is important to consider the type of fat consumed. Too much saturated fat, for example from fatty meats, full-fat dairy and some processed foods, can increase cholesterol levels in the blood and therefore increase the risk of health problems such as heart disease and stroke2.
PUFAs contain the Essential Fatty Acids (EFAs) n-6 (omega-6) and n-3 (omega-3). These are termed essential because they cannot be made in the human body and must be supplied by the diet. N-6 PUFAs are common in most diets and are present in nuts, seeds, vegetable oils and margarines. N-3 PUFAs are less common in the UK diet, and are found in oily fish (such as mackerel, salmon, tuna, herring), linseeds, pumpkin seeds and walnuts. Recommendations suggest consuming at least 2 portions of fish a week, one of which should be oily, to obtain the necessary level of n-3 PUFAs2.
Incorporating foods that supply unsaturated fats, for example, avocado, nuts, seeds, oily fish and olive oil, into the diet will increase variety and help to ensure nutrient requirements are met.
Protein in the diet
Protein has many essential functions. It is necessary for growth and repair of tissues, transport of oxygen and nutrients in the blood and cells, a healthy immune system, and regulation of fluid levels within the human body. Requirements are especially high in young people, pregnant and nursing women and following traumatic experiences or physical injury.
Common sources of protein include: meat, dairy products, fish, eggs, cereals, nuts and pulses (peas, beans and lentils). By choosing lower-fat varieties of these foods, for example, semi-skimmed milk and leaner cuts of meat you can help to reduce the total fat content of your diet whilst still enjoying the nutritional benefits of protein-rich foods. UK recommendations suggest approximately 15% of daily calories from protein sources2.
All macronutrients provide different beneficial properties and it is therefore important to ensure a balance of these within your diet.