听力原文： The term 'balanced diet' is constantly heard but rarely explained. What it means is a diet that includes a combination of several different food types, including grains, fresh fruit and vegetables, meat, dairy products, fats and oils. Crucial to the idea of a balanced diet is including foods in the right proportions the aim is to get all the nutrients your body needs while maintaining a healthy weight. The US government provides a basic idea of what nutrients we need on their website. It isn't a case of having roughly equal measures of everything. There should be a lot of some kinds and just a little of others. Some fats and oils, for example, are important in the diet for various reasons. But you only need a small amount compared with foods such as vegetables. In the UK, the Food Standards Agency has developed a programme called The Balance of Good Health to show people what proportions and types of foods make up a healthy balanced diet. This divides foods into five different groups. The largest groups are bread and vegetables, followed by milk and meat. The smallest by far is the salt and sugar group. Fresh fruit and vegetables are low in fat, calories and salt, and an excellent source of vitamins, minerals and fibre. Most of us don't eat enough to meet the current recommendation of three to five servings of vegetables and two to four servings of fruit a day. Protein-rich foods and dairy foods are needed in more moderate amounts. Your diet should include two to three servings of milk or dairy products a day, for example. (33)