How can a tailored diet support overweight diabetic cats?

In this interview with dvm360 at the 2026 Western Veterinary Conference (WVC), John Flanagan, PhD, of Royal Canin, discusses a recent study of Glycoadvanced. He explains how a high-protein, low-digestible carbohydrate formula designed for weight reduction was tested in overweight diabetic cats and what the results mean for clinical practice.

Transcript

John Flanagan, PhD: Hello. My name is John Flanagan. I am a research scientist at Royal Canin, and I have been with the company for more than 10 years. My background is in food technology. I have a PhD in food technology from the University of Limerick in Ireland, and I have held research positions in companies in France and Spain, [as well as] a postdoctoral position in New Zealand. I'm at WVC to talk about a new diabetic diet that Royal Canin is launching, Glycoadvanced. I was involved in the study design from the start, and I'm very proud to see it come to market over the [past] 3 months.

The study involved overweight diabetic cats. We wanted to see whether putting them on the new Glycoadvanced diet could help more cats achieve diabetic remission. The diet we developed focuses on the needs of overweight, diabetic cats. It is high in protein, low in digestible carbohydrates, reduced in energy, and has an increased nutrient-to-calorie ratio to meet the needs of cats during weight reduction.

For the study, we recruited 72 overweight diabetic cats that had previously been on insulin. We divided them into 2 groups. One group was fed Glycoadvanced at levels intended to maintain body weight, and the second group was fed Glycoadvanced with caloric restriction to promote weight loss.

The diabetes classification system we used came out of an advisory group meeting with experts in internal medicine and nutrition who have long worked with diabetic cats. The idea is that a diabetic cat is not a static individual with unchanging needs. Needs change over time and in response to medical and dietary treatment. We know from veterinary medicine that other classification systems, such as the [International Renal Interest Society] system for CKD [chronic kidney disease], have proven useful and have helped inform clinical decision-making. We hope the same will be true for this diabetes classification system.

The classification system is based on 4 dimensions, and cats can move within each dimension. The primary dimension is diabetic status—whether a cat is at risk of becoming diabetic, clinically diabetic, or in remission. The other 2 dimensions are body condition score and body weight evolution, which is a very good indicator of clinical progress. The final dimension is the treatment the cat is receiving for diabetes.

We were very conscious of safety when running a weight-loss program in overweight diabetic cats because this had not been done before. We consulted widely with experts experienced in weight-reduction programs for cats. For otherwise healthy overweight or obese cats, we typically recommend weight loss of about 0.5% to 2% per week, and we thought this was a reasonable target in overweight diabetic cats, as well. We put several safety measures in place to closely monitor the cats and to watch for any signs of problems during weight loss.

We saw a gap in the market for overweight diabetic cats. For diabetic cats, it is generally recommended to use a diet low in carbohydrates—specifically, low in digestible carbohydrates—because cats cannot manage large glucose loads after a meal. Weight-reduction diets on the market are typically high in total dietary fiber, reduced in energy, low in fat, and have an increased nutrient-to-calorie ratio, so cats get the nutrients they need while under calorie restriction. To show the benefits of weight reduction in overweight diabetic cats, we had to meet the needs of both groups: diabetic cats that require low digestible carbohydrates and high protein, and overweight cats that require lower energy density and an increased nutrient-to-calorie ratio.

Safety was a primary concern during the study. We monitored clinical chemistry and hematological parameters throughout the trial and were pleased to find no signs of serious adverse events. The issues we saw were mostly minor, nonclinical hypoglycemia. There were no signs of pancreatitis, hepatic lipidosis, or ketoacidosis. Renal and liver functions remained normal for most cats, with the exception of 1 cat in the control group whose CKD worsened slightly over 12 weeks.

We were fortunate that the pet owners were highly engaged, which made [adherence] much easier. We provided owners with tools to help manage the cats, including scales so they could weigh food portions daily and scales to weigh their cats. We also taught owners how to perform blood glucose curves, and for those who were not able to do a full curve, we asked for spot glucose measurements. We provided feeding stations for households with multiple cats to prevent cats from eating each other’s food. All of these measures helped owners participate in the study, and we achieved excellent [adherence].