4.1 Composition of Bulk Nutrients

Chemists recognise 92 fundamental components of matter that exist on the earth, i.e. the 92 chemical elements. Of these only six are involved in the makeup of bulk nutrients. They are:

• Carbon
• Hydrogen
• Oxygen
• Nitrogen
• Sulphur
• Phosphorus

It seems surprising that just these six, out of the fundamental building blocks of all matter, are all that is required to provide the bulk nutrients upon which we all subsist.

Fats, carbohydrate and fibre are mainly composed of:

• Carbon
• Hydrogen
• Oxygen

Some special fatty substances (called phospholipids) also contain some nitrogen and some phosphorus, and some specialised forms of carbohydrate also contain some nitrogen and some phosphorus. Sulphur (as sulphate) may also exist in combination with carbohydrate.

Proteins always contain nitrogen (which is a key element and a characteristic component of any protein), as well as carbon, hydrogen and oxygen. Sulphur is also present in most proteins, and phosphorus is present in a few.

It is when these elements, i.e. carbohydrate, fat, protein and fibre, are lacking in any situation anywhere in the world that we use the term famine or ‘food shortage’. By contrast, in countries with plentiful food, like in Western Europe or North America, almost everyone has ready access to sufficient quantities of these major nutrients. Of course, where bulk nutrients are sufficient there can still be cases of malnutrition, as this state does not often arise from any deficiency of bulk components rather from deficiencies of other minor, though equally important components, namely micronutrients. We will be examining the health consequences of micronutrient deficiencies in later modules. For now, we are going to look more closely at each of these classes of bulk nutrients.