A new family-based research initiative has explored the relationship between the consumption of ultra-processed foods (UPFs) and early indicators of insulin response in children who do not have diabetes. The findings suggest that a higher intake of these foods is associated with changes in insulin secretion and sensitivity, emphasizing the need for continued investigation into long-term metabolic health.
The Impact of Ultra-Processed Foods on Children's Metabolic Health
Ultra-processed foods, characterized by industrial processing and the inclusion of non-traditional ingredients and additives, have seen a global surge in consumption. These foods, often rich in carbohydrates, low in fiber, and highly palatable, are rapidly digested and have been linked to increased cardiometabolic risks. Proposed mechanisms include alterations in gut microbiota, increased intestinal permeability, and chronic low-grade inflammation, all of which can contribute to metabolic stress and impaired glucose regulation. The frequent consumption of easily absorbed carbohydrates and the reduced satiety provided by UPFs may also adversely affect insulin action and pancreatic responses. While most research on UPF intake focuses on advanced conditions such as obesity and diabetes, there is a recognized need to understand their early metabolic effects, particularly in children, concerning insulin sensitivity and beta-cell function. Addressing this knowledge gap is crucial for determining if UPF consumption impacts children’s metabolic health before the onset of clinical disease.
This investigation involved a secondary analysis of data from the San Antonio Family Assessment of Metabolic Risk Indicators in Youth (SAFARI) study, which enrolled children and adolescents aged 6 to 17. The cohort predominantly consisted of lower-income Mexican American families from San Antonio, many of whom had family members participating in related genetic epidemiology studies. The original SAFARI cohort showed high rates of obesity, metabolic syndrome, and prediabetes among youth. The current study utilized available dietary and insulin data from these participants, with varying sample sizes for different outcomes. Nineteen indices of insulin sensitivity and secretion were computed, with ten derived from oral glucose tolerance tests (OGTTs). Dietary intake was assessed using a Block Kids’ Food Frequency Questionnaire (FFQ) for 508 children, focusing on the frequency and quantity of 78 food and beverage items, with UPF intake specifically estimated from 61 of these items. This comprehensive approach allowed for an in-depth examination of the dietary patterns and their potential metabolic consequences in this specific population.
Associations Between UPF Intake and Insulin Dysregulation in Youth
The study participants, with an average age of 11.5 years, included an almost equal distribution of males and females, and had a mean body mass index (BMI) of approximately 22.3 kg/m². A significant portion of the cohort, over 30%, exhibited general or abdominal obesity. Prediabetes, defined by impaired fasting glucose or glucose tolerance, affected 13% of participants, while high blood pressure was observed in 12%, dyslipidemia in 32%, and metabolic syndrome in 19%. The family-based analysis, which accounted for genetic relatedness among 3,664 kinship pairs, revealed substantial genetic contributions to several insulin-related traits, supporting the use of polygenic models. These traits generally had heritability estimates exceeding 0.43, although some, like serum C-peptide and ISI0,120, yielded unreliable estimates. Notably, there were observed differences between males and females in systolic blood pressure, physical activity levels, fasting glucose, and various insulin function measures, including HOMA_β and several OGTT-based insulin indices such as Matsuda, insulinogenic, and disposition indices.
The analysis demonstrated that a higher UPF score was significantly linked to seven out of 19 insulin-related traits, even after adjusting for confounders, with a conventional p-value threshold of less than 0.05. Specifically, increased UPF consumption correlated with reduced insulin sensitivity, as indicated by HOMA_s and QUICKI, and was associated with elevated fasting insulin levels and greater insulin resistance, measured by HOMA_IR. For OGTT-based indices, higher UPF intake was associated with lower Matsuda index values and increased values for both the insulinogenic index at 30 minutes and the disposition index at 30 minutes. Nominal associations, with p-values between 0.05 and 0.10, were also noted for HOMA_β, the area under the curve for insulin (AUC_Insulin), and the triglyceride-glucose index (TyG). These results collectively suggest that greater UPF intake is associated with altered insulin sensitivity, insulin resistance, and early insulin secretion in non-diabetic children. However, it's important to acknowledge that the study did not correct for multiple comparisons across all 19 traits, implying that these findings are exploratory rather than definitive. When applying the more stringent Bonferroni threshold (p < 0.0026), only the 30-minute insulinogenic index maintained statistical significance. Adjusting for total calorie intake attenuated the significance of associations between UPF intake and fasting insulin-based indices, while strengthening those with fasting glucose-based indices. This suggests that while total energy intake plays a role, certain associations, particularly with OGTT-related indices, persist independently, indicating complex underlying mechanisms that warrant further investigation.