What are minerals?
Minerals are inorganic (not living) nutrients found naturally in many foods. Iron, calcium and zinc are examples of important minerals. Minerals are necessary for many body functions, including control of the balance of fluids in our bodies, as well as strong bones and teeth. As with vitamins, it is best to get minerals from our food, rather than take supplements.
What are vitamins?
Vitamins are special substances that our bodies need in order to function normally. Vitamins occur naturally in many foods – but no single food contains all vitamins except breast milk. Only one vitamin (vitamin D) can be made within our bodies – most have to be obtained from our food. Some vitamins can be stored in our bodies while others need to be eaten each day. We only need very small amounts of each vitamin. It is best to get vitamins from our food, rather than from supplements (except for folic acid). Too much vitamin A can be harmful during pregnancy.
Why are vegetables and fruit so important?
The next third of our plate is filled with vegetables and fruit. These foods are bursting with valuable nutrients including vitamins (especially vitamin C and folic acid) and minerals. Fruit and vegetables are our main source of antioxidants – special chemicals found naturally in foods that help protect our bodies against heart disease, cancer and the effects of pollution.
Fruit and vegetables are also a good source of fibre. Fibre (also found in cereals) is the part of our food that is not digested by our bodies. It passes through our digestive system and makes up the bulk of our faeces (bowel motion or poo). Fibre plays an important part in keeping our digestive systems running smoothly and preventing bowel diseases. If we do not have enough fibre in our diet, we may become constipated (have difficulty in passing a bowel motion).
Shopping for fruit and vegetables
If you can, buy fresh fruit and vegetables. Green leafy vegetables are good sources of folic acid. Yellow fruit such as mangoes and apricots, and citrus fruits such as oranges and grapefruits, are rich in vitamin C. But the main thing is to choose fruit and vegetables that you enjoy – and eat plenty!
Try to choose clean, undamaged items, store in a cool place and wash them well at home. Fruit and vegetables sold loose tend to be cheaper than trimmed and packaged items. Some market stall holders and green grocers sell their produce off at reduced prices at the end of the shopping day. Eat fruit and vegetables within a few days, while they are still fresh. And remember that over-cooking of vegetables will greatly reduce their vitamin content – and spoil their taste.
How much vegetables and fruit?
We cannot eat too much fruit and too many vegetables! We should all aim to eat five servings each day. A serving of fruit and vegetables is equivalent to:
What about protein?
Protein foods fit into one of the smaller sections of our plate. This may surprise some people. The traditional approach to English meal planning tended to over-emphasise our need for protein – especially for meat protein. Nutritionists now know that we do not need as much protein as previously thought.
But protein is still a very important part of our diet. We need it to repair and maintain the basic building blocks of our bodies – our cells. We also need it to grow new cells; in particular, we need protein while pregnant to grow our babies. We need protein, too, to grow new blood cells and to produce antibodies (the special cells that help our bodies fight infection). Meat protein, in particular, is rich in valuable minerals such as iron and zinc. We talk more about these nutrients in Chapter 2.
Protein comes from two food sources – animal and vegetable. Whatever the source, the basic component of protein is the amino acid. There are many different amino acids. Our bodies can make some, but most need to be taken in our diet. The balance of amino acids in animal protein (in meat, milk and eggs) is similar to the balance required by our bodies. The balance of amino acids in vegetable protein (in nuts and lentils, for example) varies from food to food. This is why people who do not eat meat or drink milk need to eat a wide range of vegetable protein in order to get a good balance of amino acids.
Pregnancy increases the need for protein – but only by a small amount. A balanced diet including 2–3 servings of protein – vegetable, meat or a mixture of both – will easily take care of the extra bit required during pregnancy.
Animal protein
Animal sources of protein include all kinds of meat and fish. Turkey, chicken and fish tend to contain less saturated fat than red meat. (Saturated fat is the most harmful type of fat.) So, if you eat red meat (such as beef, lamb and pork), try to choose lean cuts – remember, you don’t need much!
Oily fish, such as mackerel, tuna and sardines (fresh or tinned), are particularly recommended as sources of protein – because they also give us essential fatty acids. We explain more about fatty acids later in this chapter.
Vegetable protein
Vegetable sources of protein include: