Dietary Fiber Intake and Metabolic Syndrome Risk Factors among Young South African Adults

This study attempts to bridge the research gap regarding the importance of dietary fiber in reducing metabolic syndrome (MetS) risk factors in young rural South Africans. A total of 627 individuals (309 males and 318 females) aged 18–30 years participated in the study. Dietary intake was measured using a validated 24-h recall method. The consumption of different types of dietary fiber (total, soluble, and insoluble) was calculated and presented as grams. Anthropometrics, blood pressure, fasting blood glucose, and lipid profiles were measured according to standard protocols. According to the definition of the International Diabetes Federation (IDF), the prevalence of MetS was 23.1%. Overall, the total median [interquartile range (IQR)] values for total, insoluble, and soluble fiber consumed were 4.6 g [0.0–48.9], 0.0 g [0.0–18.0], and 0.0 g [0.0–15.0], respectively. Females had a higher median [IQR] intake of total (5.1 g [0.0–48.9] vs. 4.3 g [0.0–43.9]), insoluble (0.0 g [0.0–18.0] vs. 0.0 g [0.0–12.0]), and soluble fiber (0.0 g [0.0–14.9] vs. 0.0 g [0.0–7.3]) than males, respectively. The mean values for waist circumference, fasting blood glucose, and total cholesterol were higher in females than males (82.20 cm vs. 75.07 cm; 5.59 mmol/L vs. 5.44 mmol/L; and 4.26 mmol/L vs. 4.03 mmol/L, respectively), with significant differences observed for waist circumference and total cholesterol (p < 0.001 and p = 0.005, respectively). More than 97% of participants had fiber intakes below the recommended levels. After adjusting for all potential confounders (age, gender, and energy), log total fiber was inversely associated with fasting blood glucose (β = −0.019, 95% CI [−0.042 to 0.003], p < 0.05), systolic blood pressure (β = −0.002, 95% CI [−0.050 to 0.002], p < 0.05) and high-density lipoprotein cholesterol (β = −0.085, 95% CI [−0.173 to 0.002], p = 0.051) This study may be of public health relevance, providing a potential link between less dietary fiber intake and fasting blood glucose (FBG) and both systolic and diastolic blood pressure. Therefore, this observational data encourages public health policy measures to increase the consumption of dietary fiber in rural communities in order to lower the burden of MetS and its associated risk factors.