Fido just might be your ideal weight loss and fitness partner. Dogs and humans can help each other get fit, according to two new studies.

The news comes from researchers including Robert Kushner, MD, of Northwestern Medical School in Chicago. Kushner and colleagues reported their findings in Las Vegas, at the annual scientific meeting of the North American Association for the Study of Obesity.

First, the experts tracked weight loss and physical activity among 36 dog owners and 56 people without dogs. All participants were obese, with an average body mass index (BMI) of almost 36. BMI indicates total body fat. A BMI of 30 or higher is considered obese.

All participants learned lifestyle strategies for weight loss and a veterinarian taught the dog owners how to help their pets lose extra weight and become healthier. Moderate levels of physical activity at least three times a week, such as walking at a brisk pace of 3 to 4.5 miles per hour, accounted for the majority of the physical activity levels.

The dog owners fared well.

Besides losing 4.7 percent of their weight in one year, they were more persistent and physically active than those without dogs.

Dog owners also reported more physical activity throughout the study, thanks to their pets. Dog-related activities accounted for about two-thirds of total participant activity.

Likewise, humans helped hefty dogs lose weight.

Kushner’s team studied 88 dogs that were at least 20 percent over their ideal body weight but were otherwise healthy. They hypothesized that pairing up with owners in a combined weight loss program would be more efficient for both owners and pets.

Thirty-five dogs had overweight owners who enrolled in an owner-pet weight loss program; the other dogs’ owners weren’t involved in a weight loss program.

All the dogs were put on a diet to reach their ideal body weight, which they maintained until the end of the 12-month study.

The dogs in both groups lost comparable weight, yet once again, dogs and humans made a great team.

This time, 80 percent of overweight dog owners participating in a weight loss program completed the 12-month program. Only 68 percent of overweight dog owners not participating in the weight loss program completed the program.

They say that participating in exercise with your pet can improve the quality of life for you and your pet, and it is a fun and motivating way to trim down.

By Miranda Hitti, reviewed by Brunilda Nazario, MD

SOURCES: North American Association for the Study of Obesity’s Annual Scientific Meeting, Las Vegas, Nov. 14-18, 2004. News release, P-PET.