(2024) reported higher resting energy expenditure in the mid-luteal phase compared to the early follicular phase; however, this difference did not reach statistical significance and had only a small effect, although it approached significance (p = 0.061, Cohen’s d = 0.20).
In the ovulatory group (n = 12), RMR increased by 58 kcal/d during the luteal phase, representing a moderate-to-large effect size (Cohen’s d = 0.79), although the result did not reach statistical significance (p = 0.070).
(2020) also highlighted that in studies published after the year 2000, which typically employ stricter methodologies, the overall effect size was substantially reduced and often failed to reach statistical significance.