Timing of fructose intake: An important regulator of adiposity

Abstract

Summary 1. Overconsumption of fructose produces glucose intolerance, autonomic abnormalities and renal dysfunction and may be related to the worldwide epidemic of obesity and diabetes. 2. Experiments were conducted to determine whether the time period (light or dark) of fructose consumption influenced the pathological consequences. C57BL mice were given standard chow and assigned to one of three groups: (i) control (n = 10), which received water over a 24 h period; (ii) FL (n = 11), which received 10% fructose solution during the 12 h light period; and (iii) FD (n = 11), which received 10% fructose solution during the 12 h dark period. 3. There was a time related increase in body weight for all groups (P < 0.01, 2 vs 6 wks). There was a greater increase in body fat in the FL group compared with the control and FD groups. The changes in adiposity occurred even though the total caloric intake was not significantly different among the groups (approximately 18 kcal/day). Total fluid (water + fructose) consumption was greater in the FD and FL groups compared with control at 6 weeks. Significant increases were noted for plasma insulin and leptin at 8 weeks, with highest levels in the FL compared with FD group (P < 0.05). There were no significant changes in glucose, glucose tolerance, cholesterol, triglycerides or adiponectin. 4. The results of the present study suggest that there is a mismatch in caloric consumption, metabolism and adiposity as related to the light–dark cycle of fructose consumption. These findings have clinical implications in the control of bodyweight, abdominal fat accumulation and Type 2 diabetes.

Sympathetic overactivity precedes metabolic dysfunction in a fructose model of glucose intolerance in mice

“…After 60 days of fructose overload, there were increases in plasma glucose (26%), cholesterol (44%), triglycerides (22%), insulin (95%), leptin (63%), as well as glucose intolerance. These results are sup- ported by our previous study, which showed that liquid fructose intake in mice increased leptin and insulin (36). Studies in rats also showed that fructose consumption induced hypertension associated with moderate glucose intolerance, increased plasma insulin, cholesterol, and triglycerides (20,23,24).…”

“…A stimulatory effect of fructose on plasma insulin was generally reported (32,34,36). However, a previous study by Farah et al (13), reported unchanged insulin levels in fructose-fed mice.…”

Circadian rhythms and obesity: Timekeeping governs lipid metabolism

“…118 Mice with restricted access to fructose only during the light period gained more body weight and showed a greater increase in white adipose tissues than mice with nighttime restricted access to fructose. 119 Furthermore, other foods, such as caffeine and ginger, also exert a profound effect on the circadian rhythms of locomotor activity and mediate host lipid metabolism. 120,121 Angptl8 may help to explain the potential mechanism of the nutrient and circadian clock association, as it has been recently identified as a key regulator of the clock in response to food based on the signal relay of the membrane receptor PirB, the phosphorylation of kinases and transcriptional factors, and consequently, the transient activation of the central clock gene Per1.…”

Exercise Training Prevents Cardiovascular Derangements Induced by Fructose Overload in Developing Rats

“…The resulting increase in cases of morbidity and mortality such as obesity, hypertension and diabetes [2] have encouraged several studies to focus on the risk factors posed by this trend [3, 4] and the preventive strategies to fight them [5]. …”