Oral Contraceptive Pill Alters Acute Dietary Protein‐Induced Thermogenesis in Young Women

Abstract

This study shows an absence of the greater thermic effect of HP versus NP in women taking the oral contraceptive pill and has important implications regarding the effectiveness of HP for body weight regulation in women. With current obesity treatment/prevention strategies remaining largely ineffective, understanding the relationship between oral contraceptive pill use and protein-induced thermogenesis may enable the successful recalibration of existing dietary recommendations.

Gender‐specific considerations in physical activity, thermogenesis and fat oxidation: implications for obesity management

“…However, intriguingly, it appears that sex hormone status may modify our metabolic response to this macronutrient manipulation. In particular, a recent study investigating the metabolic response to a high protein meal showed that an absence of the greater thermic effect of high‐protein (24% total energy from protein) versus normal‐protein (11%) in women taking the combined, monophasic oral contraceptive pill – an important finding in the context of macronutrient recommendations for body‐weight control.…”

Assessment of the Dose–Response Relationship between Meal Protein Content and Postprandial Thermogenesis: Effect of Sex and the Oral Contraceptive Pill

“…The number of required subjects was determined by power analysis using web-based software () with a type I error (α) of 0.05 and a desired power (1 − β) of 0.90. Based on our previous work [5], to detect a difference in the area-under-curve (AUC) (normal–high protein) for EE between –OCP and +OCP of 0.05 kcal/min based on a SD of 0.04 kcal/min, a sample size of 7 subjects per group was required.…”

“…Measurements of oxygen consumption (VO 2 ) and carbon dioxide elimination (VCO 2 ) were carried out using an open-circuit indirect calorimeter equipped with a ventilated canopy (hood) system (Quark CPET, COSMED, Rome, Italy). As previously described [5], participants were seated comfortably in a car seat adapted for calorimetric monitoring, with metabolic measurements conducted for at least 30–40 min, after 15 min of rest; for each subject the mean of last 30 min was taken as the baseline (fasted) value. The ventilated hood was then removed while the subject ingested one of the three test meals described below, consumed within 10 min.…”

“…However, whilst increasing protein consumption has been shown to be somewhat effective in modulating energy balance at a macro-level [1,2], there appears to be a high degree of variability in individual responses to such interventions [3,4]. Indeed, in a recent study, we demonstrated no greater thermic effect of a high protein (24% total energy from protein) versus normal protein (11%) meal in women taking the combined, monophasic oral contraceptive pill (OCP) [5]. Although the mechanisms underpinning this differential response are not yet known, it should be noted that high protein diets administered in the context of weight management often include meals comprising about 30% of energy intake as protein, that is, higher than the 24% protein meal used in our above-mentioned study [5].…”

“…Indeed, in a recent study, we demonstrated no greater thermic effect of a high protein (24% total energy from protein) versus normal protein (11%) meal in women taking the combined, monophasic oral contraceptive pill (OCP) [5]. Although the mechanisms underpinning this differential response are not yet known, it should be noted that high protein diets administered in the context of weight management often include meals comprising about 30% of energy intake as protein, that is, higher than the 24% protein meal used in our above-mentioned study [5]. Combined with concerns about the long-term consequences of “too high” protein diets on kidney function and risks for cardiovascular diseases [6], there is therefore a need to determine whether or not the effect of contraceptive pill use on metabolic responsiveness to dietary protein persists at this higher level of meal protein content (i.e., 30% by energy), whether any sex-differences in response become apparent across a wider content range, and to establish the range of what could constitute an acceptable “high-protein” diet for weight management.…”