Investigation of Nutrition Knowledge Levels Among Fitness Center Members According to Their Metabolic Profiles

Background: This research aimed to examine the associations between the total “Nutrition Knowledge Scale” score and metabolic profile indicators among fitness center members, and to explore whether selected nutrition knowledge items differed according to daily meal consumption. Methods: The research, conducted using a cross-sectional and relational screening model, included a total of 230 volunteers, consisting of 67 women and 163 men. The participants’ HDL, LDL, fasting glucose, and triglyceride levels were obtained from biochemical analysis results via the e-Nabız system, while their nutrition knowledge levels were assessed using the “Nutrition Knowledge Scale”. Descriptive statistics, simple and multiple linear regression analyses, and one-way ANOVA were used for data analysis. Results: The total “Nutrition Knowledge Scale” score was significantly associated with LDL levels after adjustment for BMI and gender (β = −0.136, p = 0.037), whereas no statistically significant associations were observed with HDL, fasting glucose, or triglyceride levels. In secondary exploratory analyses, selected nutrition knowledge items showed significant associations with LDL levels, while the vitamin B12-related item was positively but not significantly associated with triglyceride levels (β = 0.099, p = 0.136). Additionally, responses to three selected nutrition knowledge items differed significantly according to daily meal consumption, with small effect sizes (η2 = 0.029–0.046). Conclusions: Overall nutrition knowledge was associated with LDL levels after adjustment for BMI and gender, but not with HDL, fasting glucose, or triglyceride levels. Secondary exploratory findings indicated associations between selected nutrition knowledge items, LDL levels, and daily meal consumption. Causal inference is limited by the cross-sectional design.