People eat more when they are glued to the televisio

n, and the more entertaining the programme, the more they eat, according to new research.

It seems that distracted brains do not notice what the mouth is doing, said Dr Alan Hirsch, neurological director of the Smell and Taste Treatment and Research Foundation in Chicago.

Hirsch explored the impact of smell, taste and eating behaviors while watching TV by measuring potato chip consumption.

Forty-five volunteers ate as many chips as they wanted during five-minute intervals¹ while they watched monologues² by late-night talk show hosts David Letterman and Jay Leno.

They also were given chips to eat when the television was off.

Hirsch found people ate an average of 44 per cent more chips while watching Letterman and 42 per cent more while viewing Leno, than when they did not watch TV.

"If you can concentrate on how the food tastes you'll eat less because you'll feel full faster," Hirsch said in an interview at the Endocrine Society's annual meeting in Toronto.

"So if that's the case, let's look at the opposite. What if you're distracted? If you're distracted, in theory, then you'd eat more."

Through his research at the foundation, Hirsch has helped people overcome the loss of sense and taste sensation, which typically results in weight gain because the brain does not know when it should stop eating.

The ventromedial nucleus³ in the hypothalamus, where the so-called satiety⁴ centre is located, tells the body whether it is hungry or full. If it is inhibited⁵ or tricked, the result can be changes in eating patterns, he said.

"People who cook spaghetti all day don't fell like eating spaghetti at the end of the day," said Hirsch. "By being exposed to a smell all day long it's tricking the hypothalamus."

Volunteers were asked to concentrate on the sensory⁶ characteristics of the food such as taste and smell. Researchers say these sensory clues, in addition to internal body changes, signal satiety.

But when distracted, a person does not pay attention to either the body's sensations of feeling full, or to the sensory characteristics of the food.

Many studies have linked obesity⁷ to watching television and that link is likely due to inactivity, Hirsch said. But perhaps entertaining shows are also contributing.

"If you want to lose weight, turn off the television or watch something boring," he said.

一项最新研究表明，人们在全神贯注看电视时吃得更多，而且节目越逗乐，吃得越多。

芝加哥嗅觉味觉治疗与研究基金会的神经科主任阿兰·赫尔希博士说，由此看来，注意力分散不会影响到嘴巴的动作。

赫尔希博士通过测算土豆片的摄入量，对看电视对嗅觉、味觉和进食行为的影响进行了探讨。

45名志愿者在观看大卫·赖特曼和杰·雷诺主持的午夜脱口秀节目时，在中间五分钟的休息时段大嚼土豆片。

研究人员要求他们在电视机关闭后继续吃土豆片。

赫尔希博士发现，与不看电视时相比，研究对象在看赖特曼节目时摄入的土豆片量平均多出44%，而看雷诺节目时的土豆片摄入量多出42%。

在内分泌学会在多伦多召开的年度研讨会上，赫尔希博士在接受采访时说：“如果你把注意力集中在食品的味道上，你的食量就会减少，因为你会饱得快。”

“如果这种说法成立，我们来看看相反的情况。如果你的注意力处于分散状态呢？从理论上说，你会吃的更多。”

通过在基金会所做的研究，赫尔希帮助一些人克服了感觉和味觉丧失的问题，这两种状况通常会导致体重增加，因为大脑不知道什么时候该停止进食。

他说，饱足中枢所在的丘脑腹内侧核会“告诉”身体什么时候饿了或饱了。如果它被抑制或“麻痹”，人的进食方式便会发生改变。

“做了一整天意大利面的人最后根本不想吃意大利面。整天闻一种气味，会使丘脑‘麻木’。”

研究人员要求志愿者注意食物的口味及气味等感官特征。研究人员指出，除了人体内部的变化外，这些感官提示会引起饱足感。

但人的注意力一旦分散，他就不会注意到饱足的感觉，也不会注意食物的感官特征。

赫尔希博士说，此前很多研究表明肥胖与看电视有关，这可能主要是由于不活动造成的。而娱乐节目也可能是其中的一个因素。

他说，“如果你想减肥，那就把电视机关了，或者看一些无聊的节目。”