Low Glycemic Index Starch Plus Diacylglycerol Beneficially Modifies Obesity Hormones During Canine Weight Loss
Obesity is the most common nutritional disorder in small animal medicine and is associated with several metabolic diseases. Decreasing its incidence is thus important in animal health. We previously reported that a low glycemic index starch/diacylglycerol oil dietary combination (LGIS/DAG) offered several benefits during canine weight loss. Here we report additional data investigating LGIS/DAG effects on obesity hormones. Twelve obese beagles with body condition scores of 8.4±0.1 (SEM) out of 9, and 48.9±3.3 % body fat were randomly divided into four groups. Four diets were studied: all included chicken by-product meal and either low--(LGIS, high amylose corn) or high--(HGIS, waxy corn) glycemic index starch; either diacylglycerol (DAG) or triacylglycerol (TAG) dietary oil; and vitamin/mineral pre-mixes for canine maintenance (25 % protein, 39 % fat and 36 % nitrogen-free extract, respectively (energy basis) and ca. 4200 kcal/kg DM). After a 10 week (n=3 per group) weight loss regimen, obesity was re-induced in all dogs to pre-diet body weights. After obesity re-induction, the beagles were then assigned into exactly opposite diet groups and weight loss again induced (10 weeks). All dogs were offered the equivalent calories each day to maintain their initial obese body weights. They were weighed weekly with food consumption recorded daily. During week 3, fecal samples were collected for diet digestibility trials. On week 1 and 8, post-prandial blood samples were collected via jugular catheter for glucose and gastric inhibitory polypeptide (GIP) determination using cooked chicken breast meat in place of chicken by-product meal in the diet mixture. On weeks 1, 4, 8 and 9, fasting blood samples were collected for adiponectin and leptin analyses. Data were analyzed by repeated measures ANOVA and Tukey post-hoc tests. The LGIS diet groups lost more weight than the HGIS diet group (2% vs 1% per week) due to lower digestibility of the LGIS diets. Significantly lower plasma leptin concentrations were found, consistent with weight loss in all groups and especially the LGIS/DAG group. Plasma adiponectin concentrations were significantly higher and plasma insulin significantly lower in the LGIS/DAG group compared with all other diet groups while glucose concentrations were similar. Although there were no statistically significant differences among the plasma GIP concentrations, the LGIS diet groups tended to be lower over time compared with the HGIS groups. These findings indicate that the LGIS/DAG dietary combination beneficially alters obesity hormones and, together with our earlier findings, appears to be preferred for healthy canine weight loss.