Nutrition is the process of providing or obtaining the food necessary for health and growth. It is the branch of science that deals with nutrients and nutrition, particularly in humans.

In the UK alone, over 60% of adults are currently classed as overweight or obese. Here and around the world we are faced with the challenges of an increasing obesity epidemic. Being overweight increases the risk of developing serious illnesses such as diabetes or heart disease. It is therefore essential that we learn about nutrition, not only to help ourselves but our family and friends.

Apart from breast milk for babies, there is no single food that contains all the essential nutrients the body needs to be healthy and to function efficiently. The nutritional value of a person’s diet depends on the overall balance of foods, and the nutrients obtained from those foods.

Our diets should also provide us with the right amount of energy (calories or kilojoules) from the foods that we eat and drink in order to maintain our energy levels.

In the UK, NHS advice is that, from a healthy balanced diet:-

• an average man needs around 2,500 calories / 10,500kJ a day to maintain his weight
• an average woman needs around 2,000 calories / 8,400kJ a day to maintain their healthy weight

Bear in mind though, that whilst the above are “average” amounts, the amount of energy can also depend upon age, lifestyle, size, and current health issues (of which professional doctors advise should be sought).

To get a more accurate daily calorie requirement, specific to yourself, you can calculate your BMR (Basal Metabolic Rate) which is the number of calories required to keep your body functioning at rest from this formula:-

• BMR for Men = 66.47 + (13.7 * weight [kg]) + (5 * size [cm]) − (6.8 * age [years])
• BMR for Women = 655.1 + (9.6 * weight [kg]) + (1.8 * size [cm]) − (4.7 * age [years])

To maintain our healthy well-being we need to consume the right amount of calories and ensure we burn these to maintain a healthy weight. And we need a healthy diet to include a variety of foods, from each of the main food groups, as this will allow us to get all the nutrients we need. Calories come from nutrients.

Foods are made up of a variety of nutrients. The 2 classifications are:-

1) Macro Nutrients
2) Micro Nutrients

Macronutrients – we get the energy our body needs from the food we eat. There are three types of macronutrients, and their associated calories per gram are:-

1) Protein (4 calories per gram)
2) Carbohydrate (4 calories per gram)
3) Fat (9 calories per gram)

Each of these macronutrients are broken down by the body and used to produce energy. The amount of energy they produce is referred to as a calorie.

Approximate daily dietary target percentages for macronutrients currently are:-

1) Proteins 10 – 15%
2) Carbohydrates 50 – 60% (aiming for complex carbohydrates)
3) Fats 30% (no more than 11% from saturated 13% monounsaturated and 6.5% polyunsaturated)

Micronutrients – these differ from macronutrients because they are necessary only in very tiny amounts. They are, however, essential for good health and wellbeing. Micronutrient deficiencies can cause series health issues.

Examples of micronutrients include essential dietary minerals such as zinc and iodine. Micronutrients are more commonly known as vitamins and minerals. Each micronutrient has various essential uses to the body. For example sodium, is responsible for maintaining the proper fluid balance in our bodies.

Next to The Food Groups