\ By Dr. Michael W. Fox
In the Timely Topics in Nutrition review article “Evidence does not support the controversy regarding carbohydrates in feline diets” the authors suggest that for healthy cats an upper limit of 50% of calories coming from carbohydrates in their diets is acceptable. But they also state that low carbohydrate diets can help diabetic cats and achieve remission. (1) How are we to know that a cat is diabetic until it has been fed a high carbohydrate, diabetogenic diet, to which, admittedly, many cats adapt. But they can develop other health consequences which these authors failed to address, their’ focus on dietary fat content and feline obesity being a distraction.
Many manufactured cat foods, especially dry kibble, contain phytates, which are present mainly in legumes (i.e. Soy) and cereals. These reduce the digestibility of proteins and mineral absorption (2). A net loss of body calcium, phosphorus, and magnesium during feeding of the fiber diet suggests that dietary inclusion of insoluble fiber could increase macromineral requirements of cats. Could this be a contributing factor in the widespread diagnosis of arthritis in cats?
Starch and fiber in diets potentially stimulate formation of struvite crystals. (3) Hence, reducing dietary carbohydrate is desirable to prevent struvite urolith formation.
Considering the high incidence of hyperthyroidism in the cat population, the inclusion of soy as a cheap protein in many cat foods also needs to be questioned since soy does affect the thyroid gland. (4)
I am also concerned about irritable and inflammatory bowel conditions in cats and the immunological and behavioral consequences of intestinal dysbiosis, “leaky gut” syndrome and autoimmune diseases possibly caused in part by lectins in the diet as noted in human patients (5). This may result in such cats being euthanized, abandoned, or left at an animal shelter for unlikely adoption.
The association of one of the authors of this article with Hill’s Pet Nutrition, Topeka, Kansas raises an ethical question regarding this company marketing profitable (and too-often unpalatable) special diets. Cats taken to veterinary hospitals with the above health issues are often prescribed these costly corrective diets which might well have been avoided by lower carbohydrate diets being standard fare in the market place for cat owners.
For more insights go to veterinarian Dr. Lisa A. Pierson’s website Feeding Your Cat: Know the Basics of Feline Nutrition. https://catinfo.org/
Also, The Corn Gluten Meal Cover-Up An example of how the industry can hide the truth from pet owners using the AAFCO system.
https://truthaboutpetfood.com/the-corn-gluten-meal-cover-up/
References
1.Lafamee, D.P., Backus, R.C., Forrester, D. et al Evidence does not support the controversy regarding carbohydrates in feline diets. JAVMA, 2022. 260: 506-513.
2.Samtiya, M., Aluko, R.E. & Dhewa, T. Plant food anti-nutritional factors and their reduction strategies: an overview. Food Prod Process and Nutr 2020 2, 6 . https://doi.org/10.1186/s43014-020-0020-5
4.Tonstad, S., Jaceldo-Siegl, K., Messina, M., et al. The association between soya consumption and serum thyroid-stimulating hormone concentrations in the Adventist Health Study-2. Public Health Nutrition 2016., 19(8), 1464-1470. doi:10.1017/S1368980015002943
5.Morosil, G., Anabela M., Cutine, A.M., et al. Control of intestinal inflammation by glycosylation-dependent lectin-driven immunoregulatory circuits Sci. Adv. 2021; 7::1-19.