关键区别：饥饿是身体对食物的需要。食欲是对食物的渴望。

食欲和饥饿是两个明显不同的术语。饥饿是对食物的生理需求。这是身体让你知道它需要食物，与食欲相反，食欲是一种对食物的渴望，一种即使在没有饥饿的情况下也可能存在的渴望。两者都是一个人吃饭的直接责任。

Hunger is a physical resp***e; it is when a body needs food. Once a person eats, the pancreas releases insulin, a hormone which converts the food into glucose and moves it to the cells of the body. When the body runs low on glucose, then the body needs more food. At this time, the body expressed its need for food, in the manner of hunger pangs. These usually include an empty feeling in the stomach, loud rumblings or stomach growling. This warns you that your body needs food and that it is time to eat.

Appetite, on the other hand, has nothing to do with this physical need for food. It is more of a psychological want of food. It is usually triggered通过感觉或心理反应，如视觉、气味或记忆。例如，如果你路过一家面包店时看到一块巧克力蛋糕，或者记得那一次你在一家餐馆吃了一道很棒的菜。这种心理反应会导致流涎，你想要巧克力蛋糕或那道美味的菜。这几乎与饥饿无关；然而饥饿确实会增强反应。如果你吃饱了，你往往渴望更少，而不是当你饿了，然后你开始渴望更多，甚至强烈。

However, one may also experience, a loss of appetite. This happens when a person does not feel like eating, even if they are hungry. For example, when you are sick or have a cold, nothing tastes right, so even though you are hungry and your body needs the nutrition, you prefer to skip a meal. Both hunger and appetite are natural body functi*** and necessary for healthy body.  Still, one should try to control appetite, as over indulging may lead to weight gain.