The Effect of Weight Loss Regimen on Subsequent Weight Maintenance in Dogs

Long term studies indicate that the majority of humans regain the weight lost during weight reduction programs. In dogs, while some information is available regarding weight loss programs, no data have been published regarding the ability to maintain lower weight following weight loss. The objectives of this study were to determine the ability of dogs to maintain weight loss following a weight reduction program and to determine if the degree of caloric restriction or rate of weight loss affected subsequent body weight change. Thirty-nine dogs were assigned to 4 treatment groups (100%, 75%, 60% or 50% calculated maintenance energy requirements for target body weight) and were allowed up to 16 weeks for weight loss. Following weight loss, dogs were assigned to be fed ad libitum or were fed to maintain body weight for an additional 26 weeks. All dogs were fed the same low calorie dog food throughout the study. The weights of all groups of dogs fed ad libitum during the maintenance period "rebounded", increasing by the end of week 1. The percent weight gain was correlated to the amount of weight lost and to the level of caloric restriction (p<0.01). Dogs from all weight loss treatments which were control fed to maintain weight following weight loss were able to maintain their weight loss. After 26 weeks of weight maintenance, there was no difference in weight loss between the 4 weight loss regimens. This study demonstrated that dogs, like humans, experience a weight "rebound" following caloric restriction which is greater subsequent to severe caloric restriction. The rebound effect and weight regain can be controlled by a slow rate of weight loss or by continuing to limit the dog's intake.