Mismatch of Caloric Intake and Body Fat when Fructose is provided during the Sleeping Phase

Abstract

<p>Purpose: There are concerns that high fructose consumption in humans may result in obesity and metabolic dysfunction. There is little information on whether the timing of fructose intake has an impact on the resultant pathologies. We conducted studies in mice to determine whether the timing, fructose available during only the light or dark periods, would affect body weight, body fat, glucose tolerance and total calorie intake. Methods: C57BL/6 male mice (10/group) were given either water or a 10% fructose solution ad libitum for six weeks. Groups were control (C, water only); fructose light (F12L, 12 hr fructose during light and water during dark; fructose dark (F12D, 12 hr fructose during dark and water during light. Eco MRI was used to measure body composition (fat, lean, total water and free water). Glucose tolerance was measured using an ip glucose injection (1.5g/kg). Results: After 6 wks on the diet, there were no significant differences for glucose tolerance, body weight, food or total caloric intake among the groups. F12L consumed more water as compared to F12D (8.5± 0.3 vs. 6.7±0.7ml). F12D consumed more than twice the amount of fructose as compared to F12L (15.7±0.5ml vs. 7±0.4ml). Even though the caloric intake was the same, F12L showed greater body fat than F12D or C (3.1±0.2, 2.6±0.2 and 2.4±0.2g, F12L,F12D,C, p<0.01). Conclusion: Data show that the timing of fructose consumption has important pathological consequences. When the sugar was consumed during the normal sleeping phase, there was an enhanced obesogenic action, providing implications for dietary habits in humans.</p><p>This presentation occurred at the Wright State University Campus-Wide Celebration of Research, Scholarship and Creative Activities on April 16, 2010</p>