Many primitive peoples believed that by eating an animal they could get some of the good qualities of that animal for themselves. They thought, for example, that eating deer would make them run as fast as the deer. Some savage tribes believed that eating enemies that had shown bravery in battle would make them brave. Man-eating may have started because people were eager to become as strong and brave as their enemies.

Among civilized people it was once thought that ginger root by some magical power could improve the memory. Eggs were thought to make the voice pretty. Tomatoes also were believed to have magical powers. They were called love apples and were supposed to make people who ate them fall in love.

Later another wrong idea about tomatoes grew up - the idea that they were poisonous. How surprised the people who thought tomatoes poisonous would be if they could know that millions of pounds of tomatoes were supplied to soldiers overseas during World War II.

Even today there are a great many wrong ideas about food. Some of them are very widespread.

One such idea is that fish is the best brain food. Fish is good brain food just as it is good muscle food and skin food and bone food. But no one has been able to prove that fish is any better for the brain than many other kinds of food.

Another such idea is that you should not drink water with meals. Washing food down with water as a substitute for chewing is not a good idea, but some water with meals has been found to be helpful. It makes the digestive juices flow more freely and helps to digest the food.

Many of the ideas which scientists tell us have no foundation have to do with mixtures of foods. A few years ago the belief became general that orange juice and milk should never be drunk at the same meal. The reason given was that the acid in the orange juice would make the milk curdle and become indigestible. As a matter of fact, milk always meets in the stomach a digestive juice which curdles it; the curdling of the milk is the first step in its digestion. A similar wrong idea is that fish and ice cream when eaten at the same meal form a poisonous combination.

Still another wrong idea about mixing foods is that proteins and carbohydrates should never be eaten at the same meal. Many people think of bread, for example, as a carbohydrate food. It is chiefly a carbohydrate food, but it also contains proteins. In the same way, milk, probably the best single food, contains both proteins and carbohydrates. It is just as foolish to say that one should never eat meat and potatoes together as it is to say that one should never eat bread or drink milk.

许多原始时代的人都相信，若是吃了某种动物就能得到那种动物所具备的某些优良特性。例如，他们认为，若是吃鹿肉就能跑得跟鹿一样快。某些野蛮中部落的吃人生番相信，若把在战斗中表现得很勇敢的敌人的肉吃掉了，那就会使自己变得勇敢。因为那些人很想使自己变得像敌人一样地强壮和勇敢，这才开始有了人吃人的作法。

在开化了的人们当中，一度认为生姜的根，有种魔力可以改善人的记忆力；认为蛋类的食品能使人的嗓音变得甜美；西红柿也有些魔力，把西红柿叫做爱情苹果，人们认为吃了西红柿的人会堕入情网。

关于西红柿后来又生出来一种错误观点--西红柿有毒。在第二次世界大战期间，数百万磅的西红柿曾供应给海外的士兵食用，那些认为西红柿有毒的人们，若是知道了这一史实，他们该会大吃一惊。

即使在今天，关于饮食也有许许多多的错误观点。其中有些错误观点流传甚广。

一种错误观点就是认为鱼是最佳的健脑食品。之所以认为鱼是一种很好的健脑食品，只是因为吃鱼对人的肌肉、皮肤和骨骼发育有好处。但是没有任何人能证明鱼对人的大脑比其他许多种食物都更加有什么好处。

还有一种错误观点就是，就餐时不应该喝水，用水作为一种咀嚼的代替物而把食物冲下去到胃里并不是一个好点子。但是人们发现就餐时喝点水的确有好处，水可以使胃的消化液更加自由地流动，这有助于消化食物。

有些科学家告诉我们的许多观点都是些根本没什么根据的。之所以有这些没根没据的观点都是由于各种食物的互相搭配不当所产生的。几年前有种看法很普遍，那就是在同一餐中绝不应当又喝橙汁又喝牛奶，因为橙汁中的酸性物质会使牛奶凝结成乳块因而消化不了。事实上，牛奶在胃里总会遇到胃的消化液，而这种胃液总是要把牛奶变成乳块的。把牛奶变成乳块是在消化牛奶的过程中的第一个步骤。还有一种类似的错误观点，就是在同一餐中又吃鱼肉又吃冰淇淋（甜筒）会形成一种有毒的化合物。

关于搭配食物还有一种错误观点，那就是在同一餐中不能既吃蛋白质又吃碳水化合物（淀粉）。例如，很多人认为砚是碳水化合物（淀粉）食品。是的，面包里主要是淀粉，可是面包里也含有蛋白质。同理，牛奶也许是既含有蛋白质也含有淀粉的最好的一种食品了。如果说不能把肉和土豆一起吃，这正像说不能吃面包同时又喝牛奶一样，这两种说法都是同样愚蠢的。