In a recent study published in Scientific Reports, researchers evaluated the relationship between Dietary Approaches to Stop Hypertension (DASH) and metabolic health status among Iranian overweight and obese adolescents.
Study: Association of priori-defined DASH dietary pattern with metabolic health status among Iranian adolescents with overweight and obesity. Image Credit: monticello/Shutterstock.com
Background
Adolescent overweight and obesity are global health concerns associated with metabolic conditions such as hypertension, blood lipid abnormalities, impaired glucose metabolism, and insulin resistance. These diseases increase the risk of cardiovascular disease, type 2 diabetes, and early death—lifestyle variables such as food and physical exercise influence metabolic health.
Recent studies report favorable relationships between high vegetable and fruit intake and low sugary beverages and fats, implying a link between healthy diets and metabolically healthy overweight or obesity. The DASH diet, which contains more vegetables, fruits, whole grains, legumes, seeds, and low-fat-type dairy foods, has been researched in adolescents, but disputed findings call for more research.
About the study
In the present cross-sectional study, researchers explored the metabolic impact of DASH diets among overweight and obese adolescents.
The team surveyed 203 adolescents aged 12 to 18 years with overweight or obesity status, as determined by body mass index (BMI) values using the Quetelet formula. Eligible students did not follow weight-loss diets, had no endocrinal or genetic disease, and did not use vitamin or mineral supplements or medications that could alter their metabolic profiles.
The researchers obtained dietary intake data using standardized food frequency questionnaires (FFQs). They also collected data on anthropometric parameters such as circulating insulin, blood pressure, lipid profile, and fasting blood sugar. The team characterized DASH scores based on eight components, i.e., higher intake of low-fat dairy foods, whole grains, seeds, nuts, vegetables, fruits, and legumes, and lower consumption of sodium, sweetened beverages, and processed and red meats.
The team obtained blood samples from all participants for biochemical analysis. They measured insulin levels by enzyme-linked immunosorbent assays (ELISA) and ascertained metabolic health status based on insulin resistance, determined using the International Diabetes Federation (IDF) and Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) criteria.
The researchers assessed physical activity levels using the Physical Activity Questionnaire for Adolescents (PAQ-A) and total calorie intake using the United States Department of Agriculture (USDA) food composition database. They used multivariate logistic regression to calculate the odds ratios (ORs) for the association between DASH diets and metabolic health, adjusting for age, gender, physical activity, socioeconomic status, and total calorie intake.
Results
The mean values for age and BMI of the study participants were 14 years and 27 kg/m2, respectively. Among participants, 79 (42 girls and 37 boys, 39%) suffered from metabolically unhealthy overweight or obesity (MUO) by the IDF definition, and 62 (32 girls and 35 boys, 33%) were MUO following the IDF and HOMA-IR guidelines. Using the IDF definition, MUO prevalence in the DASH diet's highest tertile was lower compared to the lowest statistical tertile (10 vs. 67%). Using HOMA-IR guidelines yielded similar findings (10 vs. 61%).
Individuals in the uppermost tertile of the DASH diet were more physically active, with higher HDL-c levels and lower blood pressure, fasting blood sugar, insulin, triglyceride, and HOMA-IR levels, compared to those in the lowest tertile. Confounder adjustment showed that individuals in the highest vs. lowest DASH tertile had 91% and 92% lower MUO odds using the IDF/IR (OR, 0.09) and IDF definition (OR, 0.08), respectively.
The highest vs. lowest DASH adherence was associated with decreased odds of hyperglycemia, hypertriglyceridemia, insulin resistance, and low HDL cholesterolemia, with odds ratios of 0.1, 0.3, 0.1, and 0.3, respectively. Subgroup analysis by BMI and sex indicated that the association was more robust among females (OR, 0.02) than males (OR, 0.09). The DASH diet likely improves metabolic health by lowering inflammation because of its high fiber, antioxidants, potassium, magnesium, and low salt content.
Conclusions
Overall, the study findings showed that increased adherence to the DASH diet was related to decreased probabilities of metabolic disease conditions among Iranian adolescents, particularly overweight girls. The study also found that adhering to the DASH diet reduced the risk of hypertriglyceridemia, hyperglycemia, insulin resistance, and low HDL cholesterol. Further research, including prospective surveys, could validate the study findings.
The inverse association observed between the DASH dietary pattern and the MUO category in the current study indicates that adolescents must increase the intake of health-associated DASH components, including fruits, vegetables, legumes, low-fat-type dairy foods, whole grains, seeds, and nuts while limiting the consumption of unhealthy foods such as processed and red meats, sweetened beverages, and salt to improve dietary quality and decrease the metabolic disease burden.
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