Sex as an independent variable in the measurement of satiation: a retrospective cohort study

Satiation is a key component of food intake regulation as it brings an eating episode to an end. The effect of sex on satiation measurement has not been characterized.

To assess the effects of biological variables on satiation.

Retrospective cohort study. We included 959 participants (mean age 39 [SD 12] years; 70.7% female, and BMI 33 kg/m² [8]) who had measurements of satiation with a nutrient-drink test to assess volume to fullness (VTF) and maximum tolerated volume (MTV), and/or an ad libitum meal test to assess calories consumed to fullness (CTF). We performed univariate and multiple regression analyses to estimate the contribution of sex to VTF, MTV, and CTF, compared to other biological variables, such as age, weight, height, BMI, waist-to-hip circumference (W/H), and lean mass percentage (LM%), that are known to affect these parameters.

Females had higher BMI, W/H, and LM%. VTF, MTV, and CTF were lower in females: 704 [323] vs. 783 [328] mL, p = 0.001; 1226 [384] vs. 1419 [410] mL, p < 0.001; and 871 [291] vs. 1086 [326] kcal, p < 0.001; respectively. Sex was a strong and independent predictor of VTF, MTF and CTF: parameter estimate [PE] = -80.8, p = 0.006; PE = -124.2, p = 0.0007; and PE = -110, p = 0.001; respectively.

Sex has a strong effect on satiation measured by VTF, MTV, and CTF, even after adjusting for other biological factors known to affect these parameters. Females seem to integrate intra-meal inhibition signals to consume fewer calories unrelated to body size or composition.

None.