People who haven't eaten for many hours turn to high-kilojoules’ foods like starches and proteins once they're free to their hunger, a new study suggests.
And, researchers found, fasters ended up eating extra of whatever foods they chose to chow down on first at that meal.
The findings carry a message for anyone who goes for long spans of time without eating, researchers said.
"I think this really pushes the importance of what (food) options you has in your environment," said Dr Aner Tal, one of the study's authors from the Cornell University in Ithaca, New York.
Dr Tal said that if he knew he wouldn't be able to eat for long periods, he would pay extra attention to what types of food he kept at home.
Don’t overstock on unhealthy options
"It would be important to not overstock on unhealthy options," he said.
For the study, published as a letter online in the Archives of Internal Medicine, Dr Tal and his colleagues recruited 128 students from Cornell University.
The students were randomly assigned to one of two groups. One group was told not to eat or drink anything after 6pm the day before the lunchtime study. The other group was able to eat normally. By the time students sat down for lunch on the test day, the fasting group had not eaten for about 18 hours.
Each student was offered a buffet lunch of dinner rolls, French fries, chicken, cheese, carrots and green beans.
Using the video logs, the researchers recorded which foods the students ate off their plates first. They also measured how much students ate by embedding scales in the lunch table.
Hospital ought to make veggies more convenient
Forty-three of the original students didn't follow their assignment and so weren't included in the main analysis.
Of the remaining 40 fasters, 30 first ate the dinner rolls, French fries, chicken or cheese, compared to 20 of 45 students in the comparison group.
Participants ended up eating almost 47% more kJ of their first-choice food compared to other menu items.
The study cannot say why some students went for the starches and proteins first, but Dr Tal said it may have something to do with an internal drive to seek high-fat foods after a period of deprivation.
The researchers suggest hospitals and cafeterias who serve people going long periods of time without food should consider these findings and make vegetables and other healthy foods "more convenient, visible, and enticing."
Pick healthy food after fasting
That, they say, may encourage people to pick healthier foods if they haven't had a chance to eat for several hours.
In a commentary published with the study, two nutrition researchers suggest the findings may apply to settings outside of hospitals and cafeterias.
They say this type of research is important for people who are experiencing hunger and food insecurity.
"I think we're just starting to understand some of these factors with obesity, food insecurity and related factors as things that interrelate. I think it will be a missed opportunity if we don't (look into this)," said Dr Amy Yaroch, one of the commentary's authors and the director of the Gretchen Swanson Center for Nutrition in Omaha, Nebraska.
(Andrew M. Seaman, Reuters Health, June 2012)