Obesity in dogs, Part 2: Treating excess weight with a multiple-modality approach
In Part 2 of our two-part discussion on overweight and obese dogs, we highlight modalities for treating the excess weight and monitoring the success of the various interventions. Effective management of excess weight in companion animals may include dietary, lifestyle, and pharmacologic modifications. Pairing interventions that benefit both the pet's and owners' health may be a valuable role for veterinarians.
Determining dietary intake
Calculate the current dietary intake, including all caloric sources, if possible.3 If this value can be determined, you could start a weight-loss program by recommending feeding the dog a total of 80% of the current energy intake. However, ideally—and certainly if the current intake cannot be determined because of ad libitum feeding, access to unmonitored feed sources, variable treat offers, or insufficient diet history—calculate the pet's maintenance energy requirement (MER) at the pet's target weight by using the equation3
MER (kcal) = 132 x body weight [kg] 0.75
Estimations for energy restrictions are inexact. The dog could remain stable, lose weight, or even gain weight. Weight monitoring and intake adjustment will likely be needed, and the pet's family must be prepared for this long-term project.
Veterinary therapeutic diets formulated for active weight loss are generally less energy dense than other diets are.4,5 The calories are diluted on a volume basis with fiber, water, or air, but these diets are not necessarily low in fat. Therapeutic diets vary widely in nutritional profiles, ingredients, and fiber concentrations, so appropriate options exist for a wide range of patients. Weight-loss diets are boosted with essential nutrients relative to calories so that when energy is restricted, protein, vitamins, and minerals are not restricted.
Feeding a maintenance diet for weight loss carries the risk of deficiency since these modifications have not been incorporated, and the diet will be fed for an extended period. That applies to situations in which owners are feeding restricted amounts of a maintenance diet only or attempting to dilute the calories of a maintenance diet with items such as green beans or pumpkin.
Recent evidence suggests high-protein diets facilitate the maintenance of lean body mass during weight loss and improve weight-loss success rates.6
Providing measuring cups may help increase compliance. Using a portion of the diet for treats or training should also be suggested, as many owners do not realize that the entire diet does not need to be fed only from the bowl.7
Clients in the habit of giving treats will likely continue to do so with or without your endorsement. As such, an effective weight-loss program should include a treat allowance with daily guidelines and specific suggestions for treats. Up to 10% of the daily calories may be allotted for treats to avoid nutrient imbalances by dilution.8,9
Dieting in people is often accompanied by repeated bouts of weight loss and regain, a phenomenon known as weight cycling or yo-yo dieting. Effects of weight cycling and obesity induction and reinduction in people and animal models have been reported.10-13 Recently, a prospective investigation of obesity induction and reinduction in nine beagles documented a significant increase of food efficiency in the obesity reinduction phase compared with the obesity induction phase—simply stated, the dogs became obese in a shorter time period at a lower calorie count (reinduction phase).14 These results demonstrated weight cycling in dogs in which rapid regain of body weight occurred after successful weight loss. These findings support the phenomenon of metabolic downregulation of energy needs with weight loss, which continues after target weights have been achieved.