Many animals recognize their food because they see it. So do humans. When you see an apple or a piece of chocolate you know that these are things you can eat. You can also use other senses when you choose your food. You may like it because it smells good or because it tastes good. You may dislike some types of food because they do not look, smell or taste very nice. Different animals use different senses to find and choose their food. A few animals depend on only one of their senses, while most animals use more than one sense.
Although there are many different types of food, some animals spend their lives eating only one type. The giant panda(大熊猫) eats only one particular type of bamboo (竹子). Other animals eat only one type of food even when given the choice. A kind of white butterfly(蝴蝶) will stay on the leaves of a cabbage, even though there are plenty of other vegetables in the garden. However, most animals have a more varied diet(多样化饮食). The bear eats fruits and fish. The fox eats small animals, birds and fruits. The diet of these animals will be different depending on the season.
Humans have a very varied diet. We often eat food because we like it and not because it is good for us. In countries such as Franch and Britain, people eat foods with too much sugar. This makes them overweight, which is bad for their health. Eating too much red meat and animal products, such as butter, can also be bad for the health. Choosing the right food, therefore, has become an area of study in modem life.

许多动物认识他们的食物因为他们看得见食物，人类也是一样。当你看见一个苹果或者一块巧克力的时候，你知道他们是你可以吃的东西。当你在选择你的食物的时候你也可以用其他的感官。你也许喜欢某些食物因为他们闻起来或者尝起来很好，你也可能不喜欢某些事物因为他们闻起来或者尝起来不好。不同的动物运用不同的感官来发现和选择他们的食物。基本上没有动物只用一种感官，大多数动物使用不止一种感官。
尽管有许多不同种类的食物，但是一些动物一生都只吃一种食物。大熊猫只吃一种特殊的竹子，其他的动物在有更多选择的时候仍然只吃一种食物。尽管花园中还有大量的其他的食物，但有一种白蝴蝶只以卷心菜的叶子为食。然而大多数动物都是多样化的饮食。熊吃水果和鱼，狐狸吃小动物，鸟和水果。这些动物们不同的饮食取决于季节的变化。
人类也是多样化的饮食。通常我们吃东西是因为我们喜欢这些食物而不是因为这些食物对我们有好处。在像法国或是英国，人们吃很多的甜食，这些甜食使他们超重，这对他们的健康是非常不好的。吃太多的不太熟的肉和动物的产品（肉、蛋什么的，译者注），比如说，黄油，对身体健康也是有害的。因此，选择正确的食物已经变成了现代社会的一个研究领域。