Short-term effects of a progestational contraceptive drug on food intake, resting energy expenditure, and body weight in young women

Background: Studies showed that hormonal fluctuations that occur over the h uman menstrual cycle affect energy intake and expenditure. However, little is known about the possible effects on body weight regulation that may aris e when these cyclic changes are suppressed with hormonal contraceptives. Objective: The aim of this study was to examine how a progestational contra ceptive drug (depot medroxyprogesterone acetate) affects food intake, resti ng energy expenditure (REE), and body weight in young women. Design: Twenty normal-weight women were tested in a single-blind, placebo-c ontrolled experiment. Body weight, REE, and 3-d food intake (food provided) were measured in the follicular and luteal phases of 2 menstrual cycles be fore a single injection of depot medroxyprogesterone or saline solution was administered. Measurements were also taken 4 times after injection: in the luteal and follicular phases of 2 cycles in the placebo group and 2 wk apa rt (to mimic timing of the menstrual phases) in the drug group. Results: Before injection, the phase of the menstrual cycle affected both e nergy intake and REE. The study participants consumed more energy (4.3%; P = 0.02) and expended more energy at rest (4.3%; P = 0.0002) in the luteal p hase than in the follicular phase. Comparison of pre- and postinjection mea ns showed that treatment with the contraceptive drug had no significant eff ects on energy intake, REE, or body weight. Conclusions: This study showed that, although phases of the menstrual cycle affected energy intake and REE, depot medroxyprogesterone acetate did not alter energy intake or expenditure or cause weight gain in young women.