Health and Wellness

Why you shouldn't make decisions on an empty stomach, according to science

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Twitter and Square CEO Jack Dorsey famously follows an incredibly restrictive intermittent fasting diet that involves eating one meal a day and fasting all weekend long. During the fasted periods, he only drinks water.

While many experts say that such extreme fasting has the potential to be very dangerous, Dorsey claims it allows him to be more productive. "During the day, I feel so much more focused," he said on the podcast Ben Greenfield Fitness: Diet, Fat Loss and Performance. "You have this very focused point of mind in terms of this drive."

But a new study from the University of Dundee shows evidence to the contrary: Researchers found that hunger can significantly impact your ability to make decisions, making you more likely to settle.

For the study, a group of 50 participants answered questions two separate times, once two hours after eating and another time after they had been fasting for 10 hours. Volunteers had the option to receive a small reward (food, money and music downloads) immediately or wait for a more substantial one later.

When people were hungry, they tended to focus on the short-term or "present-focused" rewards, whether or not they were food-related, explains Benjamin Vincent, Ph.D., the lead study author explained in a press release. (This is similar to the famous marshmallow study, which tested kids' impulsiveness and ability to delay gratification.)

"We wanted to know whether being in a state of hunger had a specific effect on how you make decisions only relating to food or if it had broader effects, and this research suggests decision-making gets more present-focused when people are hungry," he said.

Whether you intentionally fast or occasionally skip meals because you're busy, you shouldn't discount how hunger cues could affect other more important decisions that you make in life, Dr. Vincent said in the release.

"Say you were going to speak with a pensions or mortgage adviser — doing so while hungry might make you care a bit more about immediate gratification at the expense of a potentially more rosy future," he added.

Conversely, there are foods and snacking strategies that will make you feel primed for thinking and decision-making.

Snacking a few hours ahead of time on a food rich in fiber, protein or healthy fat will quell your intrusive hunger pangs, and also keep you energized and alert.

Although your grumbling stomach might seem like a nuisance when you're in an important meeting, hunger cues are powerful signals that your body needs food. Withholding food means you're denying your body and brain the energy and fuel it needs to perform tasks, from decision-making to whatever else is on your to-do list.

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