While weight-loss books have fueled the latest dieting craze among humans — researchers at Iowa State University have quietly put together a book on the nutrition requirements for cats and dogs. I-S-U animal science professor Don Beitz is one of ten experts to work on the pet nutrition guide. He says it sets the standards for requirements for pets, and he says dog and cat food companies are interested in the information too. Beitz says the last update on the information is nearly 20 years old. Unlike some of the fad human diets, he says they used documented scientific information. He says it’s information that anybody can get their hands on in libraries and other sources to verify what his committee interpreted. He says they don’t use any hearsay information or studies conducted by some group without the data readily available. Beitz’s group found around 25-percent of dogs and cats are overweight — and he says that could be linked to the problems humans have with weight. He says there’s a correlation, he doesn’t know exactly what, between obesity in humans and an overweight condition in their pets. He says it could be due to decreased activity. Beitz says it makes sense that there’s a connection, because we control what our pets eat.He says most of us with pets just put food in the bowl to keep the pet happy. He says pets can overeat and says if the pets overeat and aren’t taken out for exercise, they get fat. Beitz says there are negative consequences for overweight pets, just like humans.He says being overweight contributes to higher rates of degenerative diseases, such as diabetes in pets, just like it does in overweight humans. A preview version of the book has been released, but Beitz says they’ve since made some changes and the final version won’t be out until March.