It should come as no surprise to Americans, most of whom would rather watch TV than walk the dog, that like ourselves, our pets are increasingly overweight. A recent study by the National Research Council, a branch of the National Academy of Sciences, found that one in four dogs and cats in the western world is obese. Other studies put the number closer to one-half. Either way, people and their corpulent companions need to take a hike.

Just as overweight humans have more health problems, fat cats and portly pooches are more prone to diabetes, arthritis and other ailments. To identify the problem, here are some other helpful tips from the report: If a cat looks overweight, it is. Fat deposits on the back, face and around the abdomen are other signs of obesity. If you can’t feel your dog’s ribs, it is probably overweight. Fat deposits on the back and base of the tail and the lack of a discernable waist when viewed from above are other clues.

The 450-page NRC study assessed the nutrient and calorie requirements for cats and dogs, so it points to overfeeding and the feeding of table scraps as the key culprits. Therefore, feeding less pet food, or even a diet food, and a ban on table scraps will help solve the problem, the report said. The key, of course, is to ignore those forlorn looks pets have mastered to persuade their owners to put more kibbles into the bowl or handing over that slice of ham. If you want to keep Fido or Fluffy around, be strong and resist. A study by Purina, the animal feed maker, found that Labrador retrievers that were fed 25 percent less than the standard amount lived two years longer than their counterparts.

But, as with people, a better diet is only part of the solution. Pets need more exercise.

The same lifestyle changes that have caused humans to get heavier are also causing our pets to put on the pounds. Working people, often with long commutes from their suburban homes, lock pets inside for much of the day. After a long day of work and shuttling kids to sports and school events, many people would rather eat a quick meal and watch television than romp with a lonely, fat pooch. Cats are kept inside for fear that a car may hit them.

Setting our animals free, which once was common practice, is no longer feasible. But dog owners would clearly benefit from walking or running with their pet and cats should be given time to roam and exercise where it is safe.