Use of combined hormonal contraceptives (CHCs) is associated with reduced efficacy of weight-loss interventions after initial weight loss, according to study results published in Obesity.

In a secondary analysis of data from an 18-month behavioral weight-loss trial (ClinicalTrials.gov Identifier: NCT01985568), investigators aimed to evaluate the effect of CHC use on initial weight loss and maintenance of weight loss.

Premenopausal women aged 18 to 55 years with body mass index of 27 to 42 kg/m2 who participated in a weight-loss intervention, which consisting of a reduced-calorie diet and group-based behavioral support, were randomly assigned to progressive exercise program that began at baseline or at 6 months into the study. Use of oral CHCs was assessed at baseline and every 3 months thereafter. Changes in weight and body composition from baseline were assessed every 6 months.

Of the 110 women included in the analysis, 17 (15%) used CHCs. In both users and nonusers, 65% of participants completed the full 18-month weight-loss intervention program.


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At 6 months, both CHC users (-6.7 kg; 95% CI, -9.8 to -3.7) and nonusers (-7.7 kg; 95% CI, -9.1 to -6.4) experienced weight loss. However, between 6 and 18 months, CHC use was associated with weight gain (4.9 kg; 95% CI, 0.9 to 8.9 kg), whereas nonusers remained relatively weight stable (-0.2 kg; 95% CI, -1.8 to 1.6 kg). Overall weight loss at 18 months was lower among CHC users (-1.8 kg; 95% CI, -7.3 to 3.6 kg) compared with nonusers (-7.9 kg; 95% CI, -10.2 to -5.5 kg).

Similar trends were observed with regard to fat mass and lean mass at 6 and 18 months.

Among those who completed the weight-loss intervention, 27% of CHC users and 55% of nonusers achieved ≥5% weight loss at 18 months.

Between 6 and 18 months, self-reported dietary intake exhibited a trend towards an increased energy intake in CHC users (166 kcal/d; 95% CI, -169 to 502) compared with nonusers (-268 kcal/d; 95% CI, -268 to -132).

The researchers noted that the relatively small subset of CHC users represented a potential limitation of the study and also prevented an analysis of the effects associated with different subcategories of oral CHCs.

“CHC use was associated with weight regain after initial weight loss,” the study authors wrote. While they acknowledged that more research is needed to understand the relationship between CHC use and weight loss and maintenance, the authors also noted that “[t]hese results suggest a potential effect of CHCs on appetite, eating behavior, and/or macronutrient preference in the weight-reduced state.”

Disclosures: Authors Wyatt and Phelan report affiliations with the weight-loss industry. Please see the original reference for a full list of disclosures.

Reference

Caldwell AE, Zaman A, Ostendorf DM, et al. Impact of combined hormonal contraceptive use on weight loss: a secondary analysis of a behavioral weight-loss trial. Obesity (Silver Spring). 2020;28(6):1040‐1049.