Effects of 4-week very-high-fructose/glucose diets on insulin sensitivity, visceral fat and intrahepatic lipids: an exploratory trial

Abstract

An increasing amount of fructose in the diet is suggested to play a causal role in the pathogenesis of the metabolic syndrome, type 2 diabetes and fatty liver. Our aim was to investigate and compare the effects of very high fructose and very high glucose in hyperenergetic diets on glucose and lipid metabolism and on fat depots in healthy humans. We conducted an exploratory, prospective, randomised, singleblinded, intervention trial. Participants in addition to a balanced weight-maintaining diet received 150 g of fructose or glucose/d for 4 weeks. Insulin sensitivity was estimated from oral glucose tolerance tests. Visceral and subcutaneous abdominal fat was determined with MRI. Liver fat and intramyocellular lipids of the tibialis anterior muscle were measured with 1 H magnetic resonance spectroscopy. A total of twenty healthy subjects (fructose group n 10 and glucose group n 10; twelve males and eight females) completed the study. They had a mean age of 30·5 (SEM 2·0) years and a mean BMI of 25·9 (SEM 0·5) kg/m 2 . Insulin sensitivity appeared to decrease both in the fructose and glucose groups. TAG markedly increased in the fructose group. No strong alterations or treatment effects were found for liver fat, visceral fat, subcutaneous abdominal fat and intramyocellular lipids of the tibialis anterior muscle. In conclusion, the effects of very high fructose and very high glucose in hyperenergetic diets on glucose metabolism and body fat composition were not different in the healthy participants of the present study. However, elevation of plasma TAG seemed to be fructose-specific.

Sugar-sweetened beverage consumption and central and total adiposity in older children: a prospective study accounting for dietary reporting errors

“…In a recent study, overweight individuals randomized to drink sucrose-sweetened soda over 6 months had significant increases in intra-abdominal fat, but not total fat mass, relative to those in the isoenergetic milk condition (54) . In contrast, among healthy adults (BMI = 20-35 kg/m 2 ) participating in a 4-week weight maintenance feeding study of a diet supplemented with fructose or glucose 150 g/d (approximately 21 % of daily energy expenditure), Silbernagel et al (55) found no significant differences in changes in weight (kg), total body fat (kg) and visceral fat (kg) between diets. Additional research is needed to establish a definitive role of fructose in central fat accumulation (56) .…”

Relevance of liver fat to the impact of dietary extrinsic sugars on lipid metabolism

“…This has coincided with a furore over the link between sugar and health, and the adverse outcomes of short-term, mechanistic studies that intervened with excessive amounts of fructose or sucrose (>20 % total energy) from sugarsweetened beverages (27)(28)(29)(30)(31) . Reassuringly, the outcome of these studies have not been reproduced in interventions with moderate intakes of fructose or sucrose, especially under iso-energetic conditions, and are thus unlikely to translate to the effects produced by habitual intakes of sugar.…”

Effect of Fructose on Blood Pressure

“…The remaining 16 reports were reviewed in full. A total of 11 reports were selected for analysis, providing data for 15 trials: 13 isocaloric 14,15,17,27,28,[32][33][34][35][36] and 2 hypercaloric feeding trials, 27,37 with a median follow-up of 4.0 weeks (range: 15.5 days to 10 weeks).…”