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.

    許多原始時代的人都相信，若是吃了某種動物就能得到那種動物所具備的某些優良特性。例如，他們認為，若是吃鹿肉就能跑得跟鹿一樣快。某些野蠻中部落的吃人生番相信，若把在戰斗中表現得很勇敢的敵人的肉吃掉了，那就會使自己變得勇敢。因為那些人很想使自己變得像敵人一樣地強壯和勇敢，這才開始有了人吃人的作法。

    在開化了的人們當中，一度認為生姜的根，有種魔力可以改善人的記憶力；認為蛋類的食品能使人的嗓音變得甜美；西紅柿也有些魔力，把西紅柿叫做愛情蘋果，人們認為吃了西紅柿的人會墮入情網。

    關于西紅柿后來又生出來一種錯誤觀點--西紅柿有毒。在第二次世界大戰期間，數百萬磅的西紅柿曾供應給海外的士兵食用，那些認為西紅柿有毒的人們，若是知道了這一史實，他們該會大吃一驚。

    即使在今天，關于飲食也有許許多多的錯誤觀點。其中有些錯誤觀點流傳甚廣。

    一種錯誤觀點就是認為魚是最佳的健腦食品。之所以認為魚是一種很好的健腦食品，只是因為吃魚對人的肌肉、皮膚和骨骼發育有好處。但是沒有任何人能證明魚對人的大腦比其他許多種食物都更加有什么好處。

    還有一種錯誤觀點就是，就餐時不應該喝水，用水作為一種咀嚼的代替物而把食物沖下去到胃里并不是一個好點子。但是人們發現就餐時喝點水的確有好處，水可以使胃的消化液更加自由地流動，這有助于消化食物。

    有些科學家告訴我們的許多觀點都是些根本沒什么根據的。之所以有這些沒根沒據的觀點都是由于各種食物的互相搭配不當所產生的。幾年前有種看法很普遍，那就是在同一餐中絕不應當又喝橙汁又喝牛奶，因為橙汁中的酸性物質會使牛奶凝結成乳塊因而消化不了。事實上，牛奶在胃里總會遇到胃的消化液，而這種胃液總是要把牛奶變成乳塊的。把牛奶變成乳塊是在消化牛奶的過程中的第一個步驟。還有一種類似的錯誤觀點，就是在同一餐中又吃魚肉又吃冰淇淋（甜筒）會形成一種有毒的化合物。

    關于搭配食物還有一種錯誤觀點，那就是在同一餐中不能既吃蛋白質又吃碳水化合物（淀粉）。例如，很多人認為硯是碳水化合物（淀粉）食品。是的，面包里主要是淀粉，可是面包里也含有蛋白質。同理，牛奶也許是既含有蛋白質也含有淀粉的最好的一種食品了。如果說不能把肉和土豆一起吃，這正像說不能吃面包同時又喝牛奶一樣，這兩種說法都是同樣愚蠢的。