A nutrient is a chemical that an organism needs in order to survive and grow. They are used to build tissues and control body processes. For human beings, there are six major categories of nutrients:
• Carbohydrates
Carbohydrates are an ideal source of energy for the body because they can easily be converted into glucose, which is the form of sugar that is transported and used by the body. However, a diet that is too high in carbohydrates can disrupt the body's blood sugar level. Complex carbohydrates (like wholemeal cereals and breads) provide a slow and sustainable energy release whereas simple carbohydrates (sugary food like chocolate and sweets) are less healthy.
• Fats
Among other functions, fat provides energy, helps form cell membranes, provides insulation and is a vehicle for the provision of fat soluble vitamins. Fats are made from fatty acids (saturated, monounsaturated or polyunsaturated) and the fat in food will contain a mixture of all three in different proportions.
• Minerals
Minerals are required in small or trace amounts to ensure good health. Important minerals include calcium, iron, magnesium, sodium and zinc.
• Protein
Protein is important for growth and the maintenance of body tissue. It is made from building blocks known as amino acids (of which there are 20 different kinds). Protein is crucial in producing hormones and enzymes that control body function.
• Vitamins
Like minerals, vitamins are essential nutrients that are necessary in relatively small quantities to ensure good health. Vitamins are either water soluble or fat soluble.
• Water
Water is necessary to rehydrate the human body and replace lost fluids. Water is excreted from the body in many forms, including urine, feces, sweating and breath. Current guidelines recommend that adult females drink 2 liters of water a day and men drink 2.5 liters.
• Carbohydrates
Carbohydrates are an ideal source of energy for the body because they can easily be converted into glucose, which is the form of sugar that is transported and used by the body. However, a diet that is too high in carbohydrates can disrupt the body's blood sugar level. Complex carbohydrates (like wholemeal cereals and breads) provide a slow and sustainable energy release whereas simple carbohydrates (sugary food like chocolate and sweets) are less healthy.
• Fats
Among other functions, fat provides energy, helps form cell membranes, provides insulation and is a vehicle for the provision of fat soluble vitamins. Fats are made from fatty acids (saturated, monounsaturated or polyunsaturated) and the fat in food will contain a mixture of all three in different proportions.
• Minerals
Minerals are required in small or trace amounts to ensure good health. Important minerals include calcium, iron, magnesium, sodium and zinc.
• Protein
Protein is important for growth and the maintenance of body tissue. It is made from building blocks known as amino acids (of which there are 20 different kinds). Protein is crucial in producing hormones and enzymes that control body function.
• Vitamins
Like minerals, vitamins are essential nutrients that are necessary in relatively small quantities to ensure good health. Vitamins are either water soluble or fat soluble.
• Water
Water is necessary to rehydrate the human body and replace lost fluids. Water is excreted from the body in many forms, including urine, feces, sweating and breath. Current guidelines recommend that adult females drink 2 liters of water a day and men drink 2.5 liters.