The results of a recent study show that children who report eating more polyunsaturated fatty acids (PUFAs), found in tree nuts, seeds and fatty fish, and consume a higher ratio of PUFA: saturated fatty acids (SFAs), have more lean body mass, lower percent body fat, and less intra-abdominal fat (belly fat).
The study was conducted by researchers at the University of Colorado Anschutz Health and Wellness Centre and the University of Colorado School of Medicine at the Anschutz Medical Campus, Aurora, Colorado in collaboration with the University of Alabama at Birmingham.
The study looked at a group of racially diverse children ages 7-12 (39% European-American, 34% African-American, and 27% Hispanic-American). Each child, with parental supervision, provided two separate self-reports of their 24-hour dietary intakes.
“Studies have identified a variety of benefits of including PUFAs into an adult’s diet, particularly omega-3 fatty acids,” said Dr Michelle Cardel, the study’s lead author. “Our data suggests that consumption of PUFAs is associated with improved body composition in diverse groups of children. It’s important to note, however, that this study was cross-sectional and no causation can be concluded. Randomised experiments are needed to confirm these findings.”
Each child’s body composition and abdominal fat distribution were measured by dual energy x-ray absorptiometry and computed tomography scans, respectively. Those who ate more PUFAs and had a higher ratio of PUFA: SFAs in their reported diet were found to be leaner, have less body fat and less abdominal adiposity.
“Hopefully this work will stimulate additional research to determine if there is a causal relationship between dietary PUFAs, body fat and lean mass in kids,” Cardel said. “Until then, children should consume fatty fish, such as salmon, twice a week to reach Institute of Medicine recommendations for omega-3 fatty acids.”
Background: Polyunsaturated fatty acids (PUFAs) are associated with protection from obesity-related phenotypes in adults; however, the relation between reported intake of PUFAs with body-composition outcomes in children remains unknown.
Objective: Our objective was to examine how self-reported intakes of PUFAs, including total, n–6 (ω-6), and n–3 (ω-3) PUFAs and ratios of n–6 to n–3 PUFAs and PUFAs to saturated fatty acids (SFAs), are associated with measures of adiposity and lean mass (LM) in children. We hypothesized that higher self-reported intakes of PUFAs and the ratio of PUFAs to SFAs would be positively associated with LM and negatively associated with total adiposity.
Methods: Body composition and dietary intake were measured in a racially diverse sample of 311 children (39% European American, 34% African American, and 27% Hispanic American) aged 7–12 y. Body composition and abdominal fat distribution were measured by dual-energy X-ray absorptiometry and computed tomography scans, respectively. Self-reported dietary intakes (including total PUFAs, n–3 PUFAs, n–6 PUFAs, and SFAs) were assessed by using two 24-h recalls. Independent-sample t tests and multiple linear regression analyses were conducted.
Results: Total PUFA intake was positively associated with LM (P = 0.049) and negatively associated with percentage of body fat (%BF; P = 0.033) and intra-abdominal adipose tissue (IAAT; P = 0.022). A higher ratio of PUFAs to SFAs was associated with higher LM (P = 0.030) and lower %BF (P = 0.028) and IAAT (P = 0.048). Intakes of n–3 and n–6 PUFAs were positively associated with LM (P = 0.017 and P = 0.021, respectively), and the ratio of n–6 to n–3 PUFAs was negatively associated with IAAT (P = 0.014). All results were independent of biological, environmental, and genetic covariates.
Conclusions: Our results show that a higher self-reported intake of PUFAs and a higher ratio of PUFAs to SFAs are positively associated with LM and negatively associated with visceral adiposity and %BF in a healthy cohort of racially diverse children aged 7–12 y.