Inverse relation between dietary fiber intake and visceral adiposity in overweight Latino youth

Abstract

Background: To date, no studies have assessed the longitudinal changes of dietary intake on metabolic risk factors in Latino youth.

Objective: We assessed the relation between changes in dietary intake, specifically sugar and fiber intakes, with changes in adiposity and risk factors for type 2 diabetes in a longitudinal analysis of overweight Latino youth.

Design: Overweight Latino youth (n = 85; aged 11-17 y) underwent the following measures over 2 y [mean (+/-SD) time difference was 1.5 +/- 0.5 y]: dietary intake by 2-d diet recalls, body composition by dual-energy X-ray absorptiometry and magnetic resonance imaging, and glucose and insulin indexes by oral- and intravenous-glucose-tolerance tests. Partial correlations and repeated-measures analysis of covariance assessed the relation between changes in dietary intake with changes in adiposity and glucose and insulin indexes, independent of the following a priori covariates: sex, Tanner stage, time between visits, and baseline dietary and metabolic variables of interest.

Results: Increases in total dietary fiber (g/1000 kcal) and insoluble fiber (g/1000 kcal) were associated with decreases in visceral adipose tissue (VAT) (r = -0.29, P = 0.02, and r = -0.27, P = 0.03, for total dietary and insoluble fiber, respectively), independent of baseline covariates and change in subcutaneous abdominal adipose tissue. Participants who had decreased total dietary fiber (mean decrease of 3 g . 1000 kcal(-1) x d(-1)) had significant increases in VAT compared with participants who had increased total dietary fiber (21% compared with -4%; P = 0.02). No other changes in dietary variables were related to changes in adiposity or metabolic variables.

Conclusion: Small reductions in dietary fiber intake over 1-2 y can have profound effects on increasing visceral adiposity in a high-risk Latino youth population.

FIGURE 1

Partial correlations were performed on 85 overweight Latino children. Changes in total (A) and insoluble (B) fiber intakes (g/1000 kcal) were inversely associated with changes in visceral adipose tissue (VAT) (r = −0.29, P = 0.02, and r = 0–0.27, P = 0.03, for total and insoluble fiber intakes, respectively), adjusted for sex, Tanner stage, baseline VAT, total or insoluble fiber intake, and baseline and year 2 subcutaneous abdominal adipose tissue.

FIGURE 2

Repeated-measures ANCOVA was performed on data from 85 overweight Latino children. Participants who had decreased dietary fiber (n = 46) from year 1 to year 2 (mean decrease of 3 g · 1000 kcal⁻¹ · d⁻¹) had a significant increase in visceral adipose tissue compared with participants who had increased dietary fiber (n = 39; mean increase of 3 g · 1000 kcal⁻¹ · d⁻¹) (21% compared with −4%; P = 0.02). Models were adjusted for sex, Tanner stage, time between visits, baseline visceral adipose tissue, energy, baseline fiber intake, and baseline subcutaneous abdominal adipose tissue.