Technical issues exist with current approved approaches to calculating pet food caloric content. The Modified Atwater equation produces discrepancies when compared to the actual calorie content of pet foods as determined through feeding studies. These discrepancies are not consistent for all pet foods, and accuracy varies depending on the type and quality. For highly digestible pet foods, it may underestimate the Metabolizable Energy (ME).
Underestimating caloric content of pet foods isn’t just a numbers game, but can have effects on pet health and wellness. Adequate calorie intake is necessary for the maintenance of adult pets’ bodily functions and for supporting the proper growth and development of young dogs and cats. Pet foods, as the sole nutrition source, have feeding recommendations designed to ensure adequate calorie intake.
Contributing to overweight and obesity
Overconsumption of calories is a cause for weight gain. Small discrepancies in food calorie content could add up over time, complicating weight management. To illustrate, a small 5% miscalculation of calories in a pet food could lead to overfeeding of around 15 kcal per day; that translates into an extra 5,840 kcal annually for a 10-pound pet. Those extra calories have the potential to add a pound or more of extra body fat. In a small dog or cat, that is significant, especially if it happens year after year.
Under-estimation of ME of a pet treat or snack leads to pet owners unknowingly feeding more calories than they think, and many do not take a reduction in food calories to offset those contributed by treats. This creates a double effect of hidden extra calories from both food and treats.
Interestingly, the inaccuracy of calorie calculations extends beyond the pet food sector to human foods, too. Calorie calculations for human foods are also based on Atwater’s equations. Consequently, pet owners using human foods as treats, snacks or meal toppers may inadvertently add more calories than intended. This presents a conundrum: Even the most diligent pet owners or veterinarians, meticulously tracking a pet’s calorie intake and weight, may find themselves frustrated by unexpected outcomes, unable to reconcile their careful calorie counting efforts with actual results.
Chronic nutritional imbalances
Calorie content serves as the foundation for determining the appropriate levels of all other essential nutrients in complete and balanced pet foods. This relationship creates a cascading effect on the formulation of the entire nutritional profile. AAFCO requires that nutrient content of foods be adjusted to a 4,000 kcal/kg dry matter basis. Significant underestimation of ME content can then lead to an under-formulation of essential amino acids, trace minerals, vitamins and essential fatty acids relative to energy. This can be especially concerning in pet foods that have nutrient formulations targets at the AAFCO (Association of American Feed Control Officials) minimums.
For example, a highly digestible, fresh dog food has a calculated ME of 4,000 kcal/kg dry matter by the Modified Atwater method. This product is formulated to target the minimums of the AAFCO nutrient profiles for adult dogs also based on 4,000 kcal/kg. However, when tested, this pet food has 4,400 kcal/kg ME. If the content of essential amino acids, fatty acids and micronutrients are not calorie-adjusted, pets consuming these foods would be taking in more calories than expected, yet eat less of all other nutrients than needed. Under-nutrition can be further exacerbated when pet owners or veterinarians reduce food portions in these foods not formulated for lower calorie intakes. With sole source nutrition, chronic under-nutrition over a pet’s life is not optimal and could impact their health. Paradoxically, in people, the concept of being over-fed but undernourished is widely recognized as a complication of obesity due to availability and overconsumption of high-calorie, low-nutrient foods.
What can pet food makers do?
Pet food manufacturers can combat the pet obesity epidemic by recognizing the economic value of developing effective weight management products for the hefty overweight and obese pet populations.
Kansas State University researchers recently published an econometric analysis of survey data from dog owners that identified differentiation strategies of physical changes, perceptual changes and associated service changes for pet foods targeted to pet obesity. Approaches included low-calorie product offerings, uniquely targeted products for at-risk breeds and small dogs, pre-packaged meal portions, and leveraging educational packaging, marketing and apps to drive a brand’s product differentiation. AAFCO has defined descriptive terms for pet foods and treats desiring to make low-calorie and low-fat claims. A meta-analysis of dietary parameters leading to weight loss success in dogs revealed that dog foods containing protein >25% and fiber >12% levels support weight loss and preserve muscle, and those with fat <10% and carbohydrate <40% levels reduced body fat.
Pet food and treat makers should consider taking a page from the large and rapidly growing human weight management food product play book. Pet food manufacturers can contribute to addressing the pet obesity epidemic while also capitalizing on the growing market for pet weight control solutions.
Miscounting calories: Why pet food calorie calculations need fixing
www.PetfoodIndustry.com/15739358
Briefly: Top 5 takeaways
- The Modified Atwater equation produces discrepancies when compared to the actual calorie content of pet foods as determined through feeding studies.
- Overconsumption of calories is a cause for weight gain, and small discrepancies in food calorie content can add up over time.
- Under-estimation of ME of a pet treat or snack leads to pet owners unknowingly feeding more calories than they think.
- Calorie content serves as the foundation for determining the appropriate levels of all other essential nutrients in complete and balanced pet foods.
- Pet food manufacturers can combat the pet obesity epidemic by recognizing the economic value of developing effective weight management products for the hefty overweight and obese pet populations.