Why you should NEVER make a decision when you’re hungry

May 14, 2016

Hormone called ghrelin is produced by stomach in anticipation of a meal
Researchers have found it has a negative effect on decision making
Appetite-increasing hormone decreases our ability to control impulses

Sarah Griffiths for MailOnline

Published:
07:50 EST, 11 May 2016

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Updated:
18:19 EST, 11 May 2016

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We all know the danger of going shopping while hungry, and now experts say we shouldn’t make any important decisions while feeling peckish.

This is because a hormone called ghrelin, that’s produced by the stomach in anticipation of a meal, has a negative effect on decision making.

The appetite-increasing hormone also decreases the ability to control impulses.

Experts say we shouldn’t make any decisions while feeling peckish, because a hormone called ghrelin, that’s produced by the stomach in anticipation of a meal (stock), has a negative effect on decision making

‘For the first time, we have been able to show that increasing ghrelin to levels that are seen prior to meals or during fasting, causes the brain to act impulsively and also affects the ability to make rational decisions,’ said Karolina Skibicka of Sahlgrenska Academy, University of Gothenburg.

Her team explored impulsivity, which can be broken down into impulsive action – inability to resist a motoric response – and impulsive choice, the inability to delay gratification.

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By studying rats, the researchers found that. like us, rodents find it hard to resist a snack even when they know dinner will be served soon.

The rodents were trained to expect a sugary reward when they pressed a ‘go’ lever or when they managed to resist pressing another labelled ‘no go’.

The rats were told which action to perform by a signal of a flashing light or a buzzing sound.

When hungry, the hormone ghrelin is produced in the stomach. In a new study conducted on rats, the hormone has been shown to have a negative effect on decision making capabilities and impulse control. A stock image of the brain is pictured above

HOW TO AVOID TEMPTATION

Scientists say that whether we are right or left-handed affects whether we see things on the left or right as being more attractive.

Right-handers are drawn to things on their right, while left-handers favour items on their left.

As a result, a right-hander will view biscuits as being less tempting if they move them to the left.

In the experiment, the animals’ inability to resist pressing the ‘no go’ lever signifies impulsivity.

The researchers found rats given ghrelin directly into the brain – which mimics how the stomach would notify us of a need to eat – were more likely to press the lever instead of waiting, despite it causing them loose their reward.

The ability to delay gratification in order to get a greater reward later is a comparable measure of impulsive choice.

This could be exemplified by getting one cookie immediately or several more by waiting for five minutes, or disregarding the long-term benefits of healthy eating for an instant hit of sugar.

A person who chooses immediate gratification over a long-term benefit is characterised as being ore impulsive, implying a poorer ability to make rational decisions.

The researchers found higher levels of ghrelin stopped the rats from being able to wait for their reward.

Dr Skibicka explained: ‘Our results showed that restricting ghrelin effects to the ventral tegmental area, the part of the brain that is a crucial component of the reward system, was sufficient to make the rats more impulsive.

By studying rats, the experts found that, like us, rodents find it hard to resist a snack even when they know dinner will be served soon. A stock image of a child yearning after an ice cream is shown

‘Importantly, when we blocked ghrelin, the impulsive behaviour was greatly reduced.’

The study, published in the journal Neuropsychopharmacology, also showed increased levels of ghrelin caused long-term genetic changes in the brain circuits that are linked to impulsivity and decision making.

A ghrelin injection into the brain that resulted in impulsive behaviour in rats caused the same type of changes in dopamine related genes and enzymes as can be seen in ADHD and OCD – two behaviour disorders.

‘Our results indicate that the ghrelin receptors in the brain can be a possible target for future treatment of psychiatric disorders that are characterised by problems with impulsivity and even eating disorders,’ Dr Skibicka added.