Reduced Sugar or Increased Fiber Intake May Reduce Risk for Type 2 Diabetes in Latino Children

April 10, 2009 — Latino children who reduced added sugar intake by the equivalent of 1 can of soda per day or increased fiber intake by the equivalent of a half cup of beans had improvements in key risk factors for type 2 diabetes, according to the results of a secondary analysis of a randomized control trial reported in the April issue of Archives of Pediatrics & Adolescent Medicine.

"In previous cross-sectional analyses in overweight Latino youth, we showed that dietary fiber consumption is inversely associated with both waist circumference and the metabolic syndrome and that intake of total and added sugar is associated with poor beta-cell function, independent of adiposity," write Emily Ventura, MPH, from Keck School of Medicine, University of Southern California, Los Angeles, and colleagues.

"Additionally, we showed that in a 12-week pilot intervention study, overweight Latina girls with greater reductions in added sugar intake showed greater reductions in insulin secretion. To date, only a few studies have examined the effects of a high-fiber, low sugar diet on metabolic health in overweight youth, and to our knowledge, none have tested the effects of this type of intervention in a mixed-sex group of Latino youth."

The goal of this study was to determine if reduced added sugar intake and increased fiber intake were associated with improvements in metabolic outcomes related to type 2 diabetes mellitus risk.

At a lifestyle and metabolic measures laboratory at the General Clinical Research Center, 54 overweight Latino adolescents were randomized to 1 of 3 interventions lasting 16 weeks: control, nutrition classes, or nutrition plus strength training classes. Mean age was 15.5 ± 1 years.

The primary study endpoints were dual energy x-ray absorptiometry measurement of body composition, magnetic resonance imaging determination of visceral adipose tissue, oral glucose tolerance test, and determination of glucose and insulin incremental area under the curve; intravenous glucose tolerance test measurement of insulin sensitivity, acute insulin response, and disposition index; and 3-day records of dietary intake.

More than half (55%) of all participants decreased added sugar intake (mean decrease, 47 g/day) and 59% increased fiber intake (mean increase, 5 g/day). In all intervention groups, including control patients, percentages of those who changed sugar and fiber intake were similar.

Compared with participants who did not change their diet, those with decreased intake of added sugar had improvements in glucose incremental area under the curve (−15% vs 3%; P = .049) and in insulin incremental area under the curve (−33% vs −9%; P = .02). Participants who increased fiber intake had improved body mass index (−2% vs 2%; P = .01) and visceral adipose tissue (−10% vs no change; P = .03).

"Individuals who reduced added sugar intake by the equivalent of 1 can of soda per day or increased fiber intake by the equivalent of a 1⁄2 cup of beans showed improvements in key risk factors for type 2 diabetes, specifically in insulin secretion and visceral fat," the study authors write. Improvements occurred independent of group assignment and were equally likely to occur in control group participants."

Limitations of this study include secondary analysis, lack of blinding, and possible Hawthorne effect.

"Nutritional guidance given in the primary care or community setting may be sufficient to promote the suggested dietary changes in some individuals," the study authors conclude. "In addition, policies that promote reduced intake of added sugar and increased intake of fiber could be effective public health strategies for the prevention of type 2 diabetes in this high-risk population."

The National Cancer Institute, University of Southern California Center for Transdisciplinary Research on Energetics and Cancer, National Institute of Child Health and Human Development, the Dr. Robert C. and Veronica Atkins Foundation, and National Center for Research Resources/National Institutes of Health supported this study. The authors have disclosed no financial relationships.

Arch Pediatr Adolesc Med. 2009;163:320-327.