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

TL;DR

This pilot study found that using combined oral contraceptives for more than six months does not affect body fat or bone density, even with dietary differences.

Contribution

The study is novel in showing that COC use is not linked to body composition changes despite dietary variations.

Findings

COC users and non-users had similar body fat percentages and bone mineral density.

COC users consumed more energy from fats and had higher vitamin D levels.

Body fat percentage was negatively associated with bone mineral density.

Abstract

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).