Can nutritional literacy be an important barrier for obesity and chronic diseases?

Adequate nutritional literacy, combined with appropriate food choices, can help protect individuals from chronic diseases and enhance both individual and public health. This study aimed to examine the relationship between the nutritional literacy levels of patients receiving dietary counseling at a diet outpatient clinic and their likelihood of being obese or having chronic diseases. The study included 130 patients with chronic diseases (chronic disease group) and 99 healthy individuals (control group), aged 19 to 64. Participants' nutritional status was assessed using food consumption records. Waist circumference was measured, and body mass index (BMI, kg/m2) was calculated. Nutritional literacy levels were evaluated using the Evaluation Instrument of Nutrition Literacy on Adults (EINLA) in all participants. The mean age was 44.0 (32-53) years in the chronic disease group and 42.5 (37-50) years in the control group. Female participants constituted 55.4% (n = 72) of the chronic disease group and 63.6% (n = 63) of the control group. The mean BMI was 27.5 (24.4-30.5) in the chronic disease group and 27.0 (24.3-29.6) in the control group. Chronic diseases among participants included hypertension, diabetes mellitus, heart diseases, chronic obstructive pulmonary disease, asthma, goiter, and obesity. The chronic disease group had significantly higher EINLA scores (26.41 ± 4.94) compared to the control group (24.15 ± 5.62); however, their scores for general nutritional knowledge, reading comprehension, food label reading, and numerical literacy were significantly lower (P < .05). EINLA score (1.09 [1.03-1.14], P = .002), general nutrition knowledge (odds ratio [OR] = 0.81 [0.68-0.96], P = .018), reading comprehension-interpretation (OR = 0.45 [0.32-0.64], P < .001), and reading food labels-numerical literacy (OR = 0.77 [0.67-0.90], P = .001) were significantly associated with the likelihood of having a nutrition-related chronic disease. These associations remained significant after adjustment. Individuals with adequate nutritional literacy, as measured by the EINLA, exhibited lower BMI. Among those with chronic diseases, higher EINLA scores were inversely associated with obesity risk but positively associated with the presence of nutrition-related chronic diseases, even after adjusting for confounding factors. Furthermore, higher scores in specific EINLA subdimensions were significantly and inversely related to nutrition-related chronic disease presence. These findings underscore the complex relationship between nutritional literacy and health outcomes and suggest the possibility of reverse causality in cross-sectional studies. These findings suggest that higher nutritional literacy, particularly through targeted education on specific subdomains may act as a protective factor against obesity and chronic diseases. Promoting nutritional literacy could be a simple and cost-effective strategy to reduce the public health burden of these conditions.