Cats' physiology as obligate carnivores requires them to constantly convert protein into glucose for energy, creating distinct nutritional requirements that pet food manufacturers must understand to formulate optimal diets, according to Dr. Anna Kate Shoveller, associate professor in the department of animal biosciences at the University of Guelph.
Speaking at the American Feed Industry Association's (AFIA) Pet Food Conference during the International Production & Processing Expo (IPPE) 2026 in Atlanta, Georgia, U.S., Dr. Shoveller presented research on how feline physiology, food composition and feeding patterns shape energy metabolism in cats.
"Cats are constantly making glucose from amino acids to fuel their big brains," Dr. Shoveller said. She explained that cats have a shorter small intestine — four times body length compared to five times in dogs and humans — requiring highly bioavailable protein sources for optimal digestion and absorption.
Dr. Shoveller highlighted a critical issue with current energy calculations. "This is a completely inaccurate algorithm to be using to quantify energy density in the diet," she said of the modified Atwater Equation used on pet food packaging. "You are telling the consumer that there is less energy than there actually is in the food."
Her research demonstrates that high-protein diets increase gross energy, digestible energy, metabolizable energy and net energy beyond standard calculations. "If you have a high protein diet on the market, and you are using AAFCO or modified Atwater to calculate that energy density, you are now compounding the problem because you have even higher bioavailability of the protein coming from your high protein foods," Dr. Shoveller said.
Research from her laboratory showed that diets ranging from 23% to 41% crude protein significantly impacted energy availability. Conversely, increasing total dietary fiber from 9% to 15% decreased digestible energy, metabolizable energy and net energy, supporting fiber's role in weight management.
Dr. Shoveller also presented findings on feeding frequency. Cats fed once daily showed greater GLP-1 levels, lower physical activity but equal energy expenditure compared to cats fed four times daily. "The cats who were fed four times a day had more activity during the night because they were hungry," she said.
"I think the pet food industry is strategically placed to help the owner better manage the health of their adult cats," Dr. Shoveller said, urging manufacturers to consider feeding management recommendations alongside product formulation.
