Overweight people are overfeeding their pets and putting their animals’ health at risk. A report says a quarter of dogs and cats in the western world are obese. As with humans, this puts them at risk of diabetes, heart disease and other health problems.

The 400-page report by the National Research Council, based in the US, is aimed at scientists, pet food makers and veterinarians but also provides advice for pet owners.

It updates recommendations made in the mid-1980s, saying cats and dogs make their own vitamin C and do not need it added to food. Cats are carnivores and need meat in their diet, whereas dogs can get along on balanced vegetarian diets.

The report says that in the wild, cats will catch and eat eight to 12 small animals or birds every day. Feeding of cats should reflect this — with 12 to 20 small meals being offered in a day. “Any dog owner, on the other hand, knows that his or her dog can eat its 24-hour energy need in just a few minutes at a single meal.”