Different food types - nutrients, water and fibre

An explanation of the foodstuffs needed to have a healthy diet


The body needs a balance of nutrients to stay healthy. There are five groups of nutrients.


Macro simply means large or whole. Macronutrients need to be eaten in larger quantities than micronutrients.

ProteinsTissue growth – known as the body's building blocks. Athletes frequently use protein supplements in their diet and will consume protein immediately after training, sometimes as a 'shake'. Animal products – meat, fish, dairy; plants – lentils, nuts, seeds; protein supplements and shakes.
CarbohydratesSource of energy. Divided into: simple carbohydrates – sugars and complex carbohydrates – starches. Athletes need to consume larger quantities of carbohydrate to fuel their training and performance. Prior to an endurance event such as a triathlon, athletes might 'carbo-load' to ensure they have enough to finish the race.Simple – sugar, glucose, fructose; energy gels; complex – bread, pasta, rice, potatoes.
FatsSource of energy. Four types: monounsaturated, polyunsaturated (omega 3 and 6), saturated and trans fats. Fats are stored under the skin and are essential for health. Too much fat can limit an athlete's performance due to increased weight.Monounsaturated – olive oil, avocados; polyunsaturated – oily fish, nuts, sunflower oil, soya beans; saturated – full-fat dairy, fatty meats; and trans fats – many snack foods.


Micro simply means small. Micronutrients need to be eaten in smaller quantities than macronutrients but are absolutely essential to health.

MineralsEssential for many processes, eg bone growth/strength, nervous system, red blood cells, immune system. Need small amounts only.Calcium – milk, canned fish, broccoli; iron – watercress, brown rice, meat; zinc – shellfish, cheese, wheatgerm; potassium – fruit, pulses, white meat.
VitaminsEssential for many processes, eg bone growth, metabolic rate, immune system, vision, nervous system. Need small amounts only.A – dairy, oily fish, yellow fruit; B – vegetables, wholegrain cereals; C – citrus fruit, broccoli, sprouts; D – oily fish, eggs, fortified cereals.


The body needs to be hydrated to stay healthy. Failing to replace lost fluids can result in dehydration. This is a more serious condition than lack of food. Women should drink around 1.6 litres (approximately 8 glasses) of fluid and men should drink around 2 litres (approximately 10 glasses) of fluid per day. This varies according to the temperature and how rigorous the exercise. All drinks count but water is the healthiest. Fruit juices are fine in moderation but do contain high levels of sugar.


Fibre is an important part of a healthy diet. It is only found in plant-based foods. There are two types and each one helps the body in different ways:

  • soluble fibre – helps to reduce cholesterol, eg oats, barley, fruit, root vegetables
  • insoluble fibre – keeps the bowel healthy, eg wholemeal cereals, wholemeal bread, nuts