What Is the Effect of a High-Fat Diet on Insulin Sensitivity in Older Horses?

Insulin resistance is an associated risk factor in laminitis, equine metabolic syndrome, and equine Cushing’s disease, with aged horses at particular risk. This study was designed to examine whether short term adaptation to a high fat diet would affect insulin sensitivity in aged horses.

During the three-period study, three Thoroughbred geldings were given mixed grass/legume hay and unfortified sweet feed for the first and third periods. In the second period they were given the same amount of hay plus hay cubes and 600 ml of soybean oil. After administration of a dextrose solution by nasogastric tube, glucose tolerance tests were conducted. This was done on days 28 and 35 of each period.

Glucose was higher in the FAT group at 120 minutes compared to horses on the carbohydrate diet. Insulin in the FAT group was significantly lower at 5, 60, 90, and 120 minutes compared to horses on the carbohydrate diet. Horses on the high-fat diet produced less insulin and took longer to clear glucose from their blood.  The results of this study suggest that feeding high fat to aged horses reduced insulin sensitivity compared to a moderate high-carbohydrate diet.

Read the entire research paper, titled The Effect of Short-Term Adaptation to a High-Fat Diet on Insulin Sensitivity in Aged Thoroughbred Horses.