Animal experiment:

A total of 66 male 8-wk-old Sprague-Dawley obesity-prone (OP) and obesity-resistant (OR) rats (n = 38 per each phenotype), weighing 275 g and 210 g respectively, are used in this study. After recovery and attaining pre-surgical weights, rats undergo three training trials of 60-min sham feeding sessions with 0.03 M Sucrose solution. During testing, rats are briefly deprived of water (0900 to 1600 h) but not food, and are tested for 1 h (1400 to1500 h) sham intake of 0.03 M Sucrose solution until a stable baseline is achieved. Afterwards, rats are sham fed one of three Sucrose solutions (0.03, 0.3, and 1.0 M) in random order, every other day, with each concentration tested at least twice. Sucrose intake is individually recorded every 5 min for 60 min[1].

Sucrose is a disaccharide which is composed of two monosaccharides, glucose and fructose.

Sucrose is a disaccharide which is composed of two monosaccharides, glucose and fructose. Compare to chow-feeding, high-energy (HE)-feeding results in an overall decreased preference for Sucrose solutions in both strains. Specifically, obesity-prone (OP) rats prefer 0.3 M and 1.0 M Sucrose solutions less during HE-feeding relative to chow-feeding (P=0.046 and P=0.012, respectively). As well, obesity-resistant (OR) rats exhibit decreased preferences for 0.01 M, 0.03 M, and 1.0 M Sucrose when HE-fed compare to chow-fed counterparts (P<0.0001, P=0.043, and P=0.013, respectively). Chow-fed OP rats consume significantly less of 0.03 and 0.1 M Sucrose solutions relative to OR animals (P<0.0001, for both) while HE-fed OP rats consume less of a 0.1 M Sucrose solution only (P<0.05), compare to HE-fed OR rats[1].

[1]. Duca FA, et al. Effect of diet on preference and intake of sucrose in obese prone and resistant rats. PLoS One. 2014 Oct 20;9(10):e111232.