A balanced diet provides an adequate intake of nutrients for maintenance of the body and therefore good health. A diet can easily be adequate (67) normal body functions, yet may not be a balanced diet. An ideal human diet (68) fat, protein, and carbohydrates (碳水化合物) in correct (69) . The exact amount vary for each (70) because everyone has different metabolic (新陈代谢的) rates and levels of activity. Malnutrition results (71) an unbalanced diet, this is (72) an excess of some dietary components and (73) of other components. Too much of one component can be as much (74) to the body as too little. Energy is (75) by carbohydrates, fats and proteins. Proteins are primarily used as building blocks for (76) of many body tissues. The energy providing compounds are needed in (77) quantities in our diet. We also need much smaller amounts of other nutrients, such as vitamins and minerals. (78) the small quantities needed these are essential to provide a healthy diet as they have (79) roles in metabolic reactions. The (80) absorbed are converted to other compounds which are then used for metabolism. Starch, a major carbohydrate, can be then synthesized into fat for (81) . There are some organic compounds which in spite of being (82) for health cannot be made by cells. A balanced diet is imperative to (83) a healthy body. People who choose to be vegetarians and (84) must make sure that their diet contains all the correct nutrients to (85) any deficiencies. This is the same for people living in countries (86) their diet lacks certain important food groups.

A．therefore

B．notwithstanding

C．however

D．furthermore