Overfeeding cats does more than make them pudgy — it can harm digestion and change the gut microbiome. It’s well-known that overeating leads to weight gain in our furry friends. Researchers at the University of Illinois at Urbana-Champaign say the study’s findings are a warning to pet owners to avoid overfeeding and to encourage more activity in their cats.
How the Study Was Conducted
More than 52 percent of domestic cats in some countries are overweight, a statistic that raises concern. The research team set out to investigate how weight gain affects feline health. Kelly Swanson, a professor of nutrition and the study’s lead author, said the team wanted to “learn more about the metabolic and gastrointestinal changes that occur when cats overeat and gain weight.”
For the study, the scientists enrolled 11 “thin” spayed adult female cats. For two weeks, the cats ate a balanced, controlled diet. Then, over the next 18 weeks, they had the same food available without limits and could eat as much as they wanted. During the experiment, Swanson and her colleagues analyzed blood and fecal samples and tracked the cats’ physical activity with activity monitors.
What the Researchers Discovered
Swanson said the team expected weight gain to reduce the cats’ activity. Surprisingly, activity levels did not change consistently. Those results could differ by individual cat, by environment, and by how much owners interact with their pets, she noted. Predictions about weight gain were confirmed: as the cats ate more and gained weight, body fat increased and nutrient digestion declined, ScienceAlert reported.
“When the body gets less food, it extracts nutrients more efficiently. But when more food is present, it moves through the digestive system faster, so fewer nutrients are absorbed,” Swanson explained. The more the cats ate, the more frequently they defecated, and their feces became more acidic — signs the food wasn’t being digested effectively.
The researchers found differences in the types of microbes living in the cats’ intestines before and after the 18 weeks of unrestricted feeding. The team also found that gastrointestinal transit time decreased by about 25 percent during the weight-gain period. Some changes in the cats’ microbiomes contradicted patterns seen in obese humans, suggesting that factors beyond excess weight may be involved.
Understanding these metabolic and gastrointestinal shifts could help prevent and treat obesity in cats. The team plans to examine next how changes in the gut microbiota relate to overall feline health.
No cats were harmed during the experiments. Swanson and her colleagues also showed that portion control can help cats lose weight safely. At the end of the study, all 11 animals were placed on a special diet that helped them shed pounds and return to a healthy weight. Cats don’t like being told what to do, but our independent companions can live healthier, happier lives with the right intervention.
The results of the study were published in the Journal of Animal Science.
