Isocaloric fructose restriction and metabolic improvement in children with obesity and metabolic syndrome.
Level 4 - case-series / case-control
Single-arm before-and-after intervention study without a concurrent control group.
PubMed 26499447 · doi:10.1002/oby.21371
What was done
Latino (n = 27) and African-American (n = 16) children with obesity and metabolic syndrome participated in a 9-day dietary intervention. The intervention matched each participant's self-reported baseline macronutrient proportions (protein, fat, and carbohydrate), but reduced dietary sugar from 28% to 10% of total energy intake by substituting it with starch. Participants recorded daily weights to allow calorie adjustments aimed at weight maintenance. Oral glucose tolerance testing and dual-energy X-ray absorptiometry were conducted on Days 0 and 10, with biochemical analyses adjusted for weight change via repeated measures ANCOVA.
What was found
Diastolic blood pressure decreased by -5 mmHg (P = 0.002), lactate by -0.3 mmol/L (P < 0.001), triglycerides by -46% (P < 0.001), and LDL-cholesterol by -0.3 mmol/L (P < 0.001). Glucose tolerance and hyperinsulinemia improved (P < 0.001). Despite weight-maintenance aims, participants lost 0.9 ± 0.2 kg of weight (P < 0.001) and 0.6 kg of fat-free mass (P = 0.04). A post hoc sensitivity analysis in participants who did not lose weight (n = 10) showed directionally consistent results.
Why it matters
This study provides proof-of-concept evidence that reducing dietary sugar and fructose improves surrogate cardiovascular and metabolic markers in youth with metabolic syndrome independently of total caloric intake.
Limits
The study lacked a randomized control group, making it susceptible to secular trends or study-effect confounding. The sample was small (n = 43), limited to Latino and African-American children, and evaluated over a very short duration (9 days). Unintended weight loss occurred despite calorie adjustments, and baseline diets were self-reported.
Cited by
- supports Studies at UCSF showed that eating real food reduces insulin, fatty liver, uric acid, and ALT in nine days.