Effects of Dietary Fructose Restriction on Liver Fat, De Novo Lipogenesis, and Insulin Kinetics in Children with Obesity.
Gastroenterology. 2017 Jun 1. Epub 2017 Jun 1. PMID: 28579536
BACKGROUND & AIMS: Consumption of sugar is associated with obesity, type 2 diabetes mellitus, non-alcoholic fatty liver disease, and cardiovascular disease. The conversion of fructose to fat in liver (de novo lipogenesis, DNL) may be a modifiable pathogenetic pathway. We determined the effect of 9 days of isocaloric fructose restriction on DNL, liver fat, visceral fat (VAT), subcutaneous fat, and insulin kinetics in obese Latino and African American children with habitual high sugar consumption (fructose intake more than 50 g/day).
METHODS: Children (9-18 years old; n = 41) had all meals provided for 9 days with the same energy and macronutrient composition as their standard diet, but with starch substituted for sugar, yielding a final fructose content of 4% of total kcal. Metabolic assessments were performed before and after fructose restriction. Liver fat, VAT, and subcutaneous fat were determined by magnetic resonance spectroscopy and imaging. The fractional DNL area under the curve value was measured using stable isotope tracers and gas chromatography/mass spectrometry. Insulin kinetics were calculated from oral glucose tolerance tests. Paired analyses compared change from day 0 to day 10 within each child.
RESULTS: Compared with baseline, on day 10, liver fat decreased from a median of 7.2% (inter-quartile range, 2.5%-14.8%) to 3.8% (inter-quartile range, 1.7%-15.5%)(P<.001) and VAT decreased from 123 cm(3) (inter-quartile range, 85-145 cm(3)) to 110 cm(3) (inter-quartile range, 84-134 cm(3)) (P<.001). The DNL area under the curve decreased from 68% (inter-quartile range, 46%-83%) to 26% (inter-quartile range, 16%- 37%) (P<0.001). Insulin kinetics improved (P<.001). These changes occurred irrespective of baseline liver fat.
CONCLUSIONS: Short-term (9 day) isocaloric fructose restriction decreased liver fat, VAT, and DNL, and improved insulin kinetics in children with obesity. These findings support efforts to reduce sugar consumption. ClinicalTrials.gov no: NCT01200043.