University of Roehampton and Simon Fraser University uncover surprising new findings on weight loss in Zebra Finches.
A new study conducted by Professor Lewis Halsey from the University of Roehampton, along with Brett Hodinka and Tony Williams from Simon Fraser University, sheds new light on how birds regulate body weight—potentially providing clues about why staying slim might be easier for some people. Contrary to the traditional belief that body weight is solely determined by diet and exercise, this study reveals that, remarkably, birds can rapidly decrease their body mass without reducing food intake or increasing activity.
The research, which focused on zebra finches (Taeniopygia guttata), discovered that these birds could lose weight quickly and in an unidentified way when they perceived themselves to be heavier. Researchers tricked the birds into believing they had gained weight by attaching weighted backpacks to them. Over just two days, the birds nevertheless shed weight through an unknown mechanism, despite maintaining their usual diet and despite lowering their physical activity. And all while eating the equivalent of an ultra-processed diet.
The findings suggest that zebra finches assess their body mass using a physical mechanosensory pathway, rather than through physiological changes or stress responses.
“This research challenges the conventional understanding of energy balance,” said Professor Lewis Halsey, one of the study’s lead researchers. “Birds seem to have mechanisms that allow them to force a negative energy balance and lose weight, even when their food intake remains the same.”
These findings have broad implications, suggesting that humans may also possess lesser-known mechanisms that influence weight regulation beyond diet and exercise alone. This opens new avenues for research into weight management and energy balance, in terms of how it is that some people seem able to stay slim regardless of what they eat, while others quickly put on weight.
Find out more about our research at the Centre for Integrated Research in Life and Health Sciences.