Why zoos may be feeding bears the wrong diets—and how to fix it

Bears have diverse dietary needs that often differ from what zoos traditionally provide. New research shows that many species, including giant pandas and sloth bears, thrive on specific nutrient balances rather than high-protein diets. Giant pandas naturally favour carbohydrate-rich bamboo stalks over protein-dense leaves. This aligns with their classification as low-protein, high-carbohydrate omnivores. In contrast, sloth bears prefer fat-rich foods like avocados when given a choice.

Grizzlies achieve optimal weight gain with a balanced mix of protein, fat, and carbohydrates. However, zoos have often fed polar bears, brown bears, and sloth bears as if they were strict carnivores, which may harm their health. Sloth bears in captivity have been observed to die up to 20 years earlier than wild ones, possibly due to excessive protein intake.

Professor Charles Robbins notes that bears instinctively select foods that optimise their health. Unlike cats, which require protein-heavy diets, bears are omnivores, much like humans. This suggests they understand their nutritional needs better than previously thought. The findings highlight the importance of tailoring bear diets to their natural preferences. Zoos may need to reconsider current feeding practices to improve the health and longevity of captive bears. Adjusting diets could help prevent premature deaths and support better fitness in these animals.