A new study from researchers with the University of Alabama at Birmingham’s Department of Nutrition Sciences suggests consumption of a moderately carbohydrate-restricted diet may result in decreased fatty liver tissue, as well as improvements in body composition and insulin resistance, in adolescents with non-alcoholic fatty liver disease.
NAFLD has emerged as the most common form of liver disease among adolescents in industrialized countries, according to the study, reaching 40 percent in children with obesity. For children and adolescents ages 2 to 19, the prevalence of obesity has reached 17 percent and affects nearly 13 million children in the United States.
Lead author Amy Goss, Ph.D., assistant professor of nutrition sciences, says understanding the effectiveness of lifestyle interventions as long-term solutions in treating this condition in child and adolescent populations is critical.
“For many children, NAFLD ends up progressing, and by the time they are adults, they may have other health complications or may even need a transplant,” Goss said. “There have been other studies done that focus more on removing added sugars; but to our knowledge, this is the first study to test the effectiveness of overall diet quality.”
The primary objective of the pilot study was to compare the effects of an individualized weight-maintaining, high-quality, lower-carbohydrate diet, versus a lower-fat diet, in 32 children and adolescents with NAFLD, on reducing liver fat and Type 2 diabetes risk using a family-based intervention with a two-week feeding phase and a six-week free-living phase.
The moderately CHO-restricted diet was designed to minimize intake of refined carbohydrates like added sugars, high glycemic grains and fructose. The fat-restricted diet limited high-fat foods like butter, cream cheese, fried food and bacon.
All groceries were provided to the families by a grocery delivery service for the first two weeks during the modified controlled feeding phase. During the entire intervention, parents and guardians were encouraged to adopt the prescribed diet for the entire family. Participants were asked to complete a three-day food diary at week four of the intervention.
“Family involvement can predict successful adherence to diet,” Goss said in the study.
Goss and her team found significantly different results when comparing the CHO-restricted vs. fat-restricted diets, reporting that the participants in the CHO-restricted group on average lost one-third of their liver fat in just eight weeks, in addition to significant reductions in weight, BMI, total fat mass and abdominal fat.
“We were encouraged to see that big a change in such a short amount of time,” Goss said. “What this means is that an emphasis on weight loss may not be necessary, but just improving quality of diet could improve overall health in these age groups.”
Goss says larger studies are needed to more accurately test the impact of the two diets on NAFLD.
Funding for this study was provided by the National Institute of Diabetes and Digestive and Kidney Diseases grants P30DK56336 and P60DK079626.