Effect of feeding a high-carbohydrate or a high-fat diet on subsequent food intake and blood concentration of satiety-related hormones in dogs

Although studies in rodents and humans have evidenced a weaker effect of fat in comparison to carbohydrates on the suppression of food intake, very few studies have been carried out in this field in dogs. This study investigates the effects of a high-carbohydrate (HC) and a high-fat (HF) diets on subsequent food intake and blood satiety-related hormones in dogs. Diets differed mainly in their starch (442 vs. 271 g/kg dry matter) and fat (99.3 vs. 214 g/kg dry matter) contents. Twelve Beagle dogs received the experimental diets at maintenance energy requirements in two experimental periods, following a cross-over arrangement. In week 7 of each period, blood concentrations of active ghrelin, glucagon-like peptide (GLP-1), peptide YY, insulin, and glucose were determined before and at 30, 60, 120, 180, and 360 min post-feeding. The following week, intake of a challenge food offered 180 min after the HC and HF diets was recorded over two days. In comparison to the dogs on the HC diet, those on the HF diet had a higher basal concentration of GLP-1 (p =.010) and a higher total area under the curve over 180 min post-prandial (tAUC) (p =.031). Dogs on the HC diet showed a higher elevation of ghrelin at 180 min (p =.033) and of insulin at 360 min (p =.041), although ghrelin and insulin tAUC did not differ between the two diets (p ˃.10). Diet had no effect on challenge food intake (p ˃.10), which correlated with the tAUC of ghrelin (r =.514, p =.010), insulin (r = −.595, p =.002), and glucose (r = −.516, p =.010). Feeding a diet high in carbohydrate or fat at these inclusion levels does not affect the feeding response at 180 min post-prandial, suggesting a similar short-term satiating capacity.This work was funded by Affini Petcare, with the participation of the Department of Industry and Innovation of the Government of Aragón and the European Social Fund. The authors wish to thank the Servicio de Apoyo a la Investigación (SAI) team for their dedicated dog care and for their invaluable assistance with sampling. We also thank the laboratory technicians of the Animal Nutrition Unit of the Faculty of Veterinary Sciences of Zaragoza for carrying out the analysis of food and faeces.Peer Reviewe