Researchers in Hungary who found that normal and overweight dogs behaved differently in tasks involving food say the dogs' responses were similar to those that might be expected from normal and overweight humans.
The study suggested dogs could be used as models for future research into the causes and psychological impact of human obesity, the authors of the paper from Budapest's ELTE University said.
Researchers put two bowls — one holding a good meal, the other empty or containing less attractive food — in front of a series of dogs.
The study found that canines of a normal weight continued obeying instructions to check the second bowl for food, but the obese ones refused after a few rounds.
"We expected the overweight dog to do anything to get food, but in this test, we saw the opposite. The overweight dogs took a negative view," test leader Orsolya Torda said.
"If a situation is uncertain and they cannot find food, the obese dogs are unwilling to invest energy to search for food — for them, the main thing is to find the right food with least energy involved."
The behavior had possible parallels with overweight people who see food as a reward, said the paper, which was published in the Royal Society Open Science journal.