Dietary fat and sugar induce obesity and impair glucose tolerance in prepubertal pigs

Abstract

A translational swine model of childhood obesity was used to determine the interaction between dietary energy source, body adiposity, and oral glucose tolerance (OGT). Prepubertal female pigs weaned at 21 d of age were fed control (C), refined sugar (S), fat (F), and sugar‐fat (HE) diets in a 2×2 factorial arrangement for 16 wk. Calories from fat were 8.9% for C, 5.6% for S, 35.5% for F and 32.3% for HE. Calories from sugar were 36.0% for S and 30.7% for HE. Adding fat or sugar increased (P<0.003) calorie intake indicating impaired ability to regulate energy consumption. Daily fat accretion and percent body fat were higher (P<0.03) in all treatments compared to C, and in HE compared to S. Ultrasound backfat depth was associated (P<0.001) positively with percent body fat (r2 = 0.909) and negatively with percent body protein (r2 = −0.912). Fat and sugar intake raised (P<0.02) plasma cholesterol levels. Glucose area under the curve (AUC) in response to OGT at 14 wk was higher (P<0.03) in F (+15%) and HE (+32%) pigs compared to C. Glucose AUC from S‐fed pigs was not different (P=0.2) from C‐ or F‐fed pigs. Adding sugar, fat, or their combination to diets increased (P<0.008) glucose AUC. Inclusion of fat in the diet reduced (P<0.001) insulin AUC during OGT, while sugar had no effect. Inclusion of fat and refined sugar in pig diets increases body adiposity and impairs glucose homeostasis. College of Agriculture and Life Sciences