The Use of Combined Oral Contraceptives for ˃6 Months Is Not Associated with Body Fat or Bone Density, Regardless of Dietary Differences—A Pilot Study

Background and Objectives: There is a lack of information on the dietary intake of long-term combined oral contraceptive users (COC-users) in relation to their body composition. The aim of the pilot study was to determine the food consumption of young women using COCs for >6 months and its relationship to body composition compared to non-users. Materials and Methods: A total of 45 healthy women (21.8 ± 1.7 years) were divided into COC non-users (n = 19) and users of a low (≤20 μg) ethinylestradiol (EE) dose (n = 18) and a medium (30–35 μg) EE dose (n = 8). Anthropometric data, body composition, physical activity levels, three-consecutive-days of dietary records, and serum concentrations of calcium, magnesium, and vitamin D were assessed. Statistical methods included chi-squared, Fisher’s exact test, t-test, Mann–Whitney U test, Spearman’s correlation, and multiple linear regression. Results: There were no differences between COC-users and non-users in terms of physical activity, intake of micronutrients, body mass index, body fat percentage (BF%), or bone mineral density (BMD). COC-users consumed a higher percentage of energy from fats (p = 0.02) and had higher serum vitamin D levels (p < 0.01). BF% was negatively associated with BMD (coefficient −0.008; p = 0.027). Conclusions: The use of COCs for ˃6 months is not associated with FM or BMD, regardless of dietary differences. Further attention should be paid to possible associations between COCs use, dietary habits, and body composition (including BMD).