Seven ways our bodies tell us we're hungry--even when we're not.

Time of Day

Through routine, we condition our bodies to expect breakfast, lunch and dinner at the same time each day, says Randy Seeley, a professor of psychiatry at the University of Cincinnati." Part of the reason you're hungry at noon is because that's the time you've eaten for the last 100 days."

Sight

Research using MRIs shows that brain patterns of people viewing photos of foods they like and foods they don't like are "very different," Seeley says. "The body anticipates when food is about to enter the system." And that's why your mouth starts watering when you see Mom's pie.

Variety

Even after eating a large meal, we often "make room" for dessert, because a desire for sweets hasn't been satisfied. Ann Gaba, a registered dietitian at New York Presbyterian Hospital, says that sometimes all it takes is a bit of fruit in a salad during a meal to curb a sugar craving.

Smell

Scent is one of the key ways we cue our bodies that food is near. Once the trigger goes off, it can induce the insulin secretion that makes us think we're hungry. Says Sharron Dalton, a nutrition professor at New York University: "Smell and sight alone activate the appetite cascade."

Alcohol

Drinking has not been scientifically proved to stimulate appetite, but too much beer, wine or liquor can impair judgment, causing us to eat more. "Most people who are on a diet will say it's a lot harder to push themselves away from the table if they've been drinking," observes Seeley.

Temperature

The colder the temperature, the more people tend to eat, which is why restaurants often keep thermostats low. "Your metabolism drops when it's time to eat, and eating warms you up," says David Ludwig, professor of pediatrics at Harvard. "Heat is a satiety signal."

Refined Carbs

After a meal heavy in refined carbohydrates, like white pasta, the body may crave food again within only a few hours. These foods cause blood sugar to drop, and "when our blood sugar is crashing, we're going to be a lot more interested in food in general," Ludwig says.

身体以以下七种方式给我们传达饿了的信息，即使有时我们并不饿。

时间

“按一般规律，我们的身体会在每天差不多相同的时段期待进早餐、中餐和晚餐，”辛辛那提大学精神病学教授兰迪.西利说，“你在中午感到饥饿的部分原因是因为在过去的一百天里你差不多都在这个时间吃中饭。”

视觉效果

“使用核磁共振成像查看人们看自己喜欢或不喜欢的食品照片时的人脑模式，研究表明结果非常不同，”西利说。“当食物即将进入该系统时，身体就开始期待了。”这就是为什么当你看到妈妈做的馅饼时就开始垂涎三尺。

多样化

即使刚吃过大餐，我们通常仍然能塞下一份甜点，因为想吃甜点的需求未被满足。纽约长老会医院的注册营养师安加巴表示，有时只要在进餐期间有一点水果沙拉，就能控制我们对糖分的需求。

气味

气味是提示我们的身体我们跟食物很接近的一个关键因素。一旦触发了这个欲望，它可以促使胰岛素分泌，使我们认为自己饿了。纽约大学营养学教授莎伦.道尔顿说：“仅嗅觉和视觉就能激活我们的胃口。”

酒精

从科学的角度来讲，少量饮酒的确能刺激食欲，不过过量的啤酒、红酒、烈性酒会麻痹我们的判断力，导致我们进食过多。“正在节食的很多人将会说如果自己正在喝酒的话就很难从餐桌边走开。”西利说。

周围的温度

温度越低，人们会倾向于吃更多的食物，这就是问什么餐厅总是把空调开得比较低。“进餐环境的温度比较低时，人体的新陈代谢在下降，吃东西能让你感觉暖和些。”哈佛大学儿科教授大卫.路德维希说，“燥热是饱腻的信号。”

精制的碳水化合物

在进食大量像白面条类的精制碳水化合物后，人体可能会在几个小时内就又想吃东西了。这些食物导致血糖下降，“当血糖降低，通常我们就会对食物比较有兴趣了，”路德维希说。