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. Author manuscript; available in PMC: 2022 Nov 15.
Published before final editing as: Genes Brain Behav. 2021 May 12:e12751. doi: 10.1111/gbb.12751

Figure 2. Change in body weight and palatable food (PF) intake during binge-like eating, PF-CPP, and power analysis in C57BL/6J x DBA/2J-F2 mice.

Figure 2.

(A): Change in body weight [BW; % of Day (D)1] across binge-like eating training days from D2 through D18; prior to assessment of compulsive-like eating on D23. RM ANOVA indicated a main effect of Sex (F1,129 = 24.96, p < 0.0001), Day [Greenhouse-Geisser-adjusted (epsilon for “Day” = 0.53): F2.65,341.85 = 187.53, p < 0.0001], and an interaction (Greenhouse-Geisser-adjusted: F2.65,341.85 = 14.91, p <0.0001). Tukey’s post-hoc comparison indicated that males gained significantly more %BW compared to females on D11, D16, and D18 (*all psadjusted < 0.05). (B): Slope of % increase in body weight (BW) from D2 through D18 in F2 females (n = 66) and in F2 males (n = 65). Unpaired Student’s t-test revealed a significantly steeper rise in % increase in BW over binge-like eating training days in males compared to females (t129 = −5.13, *p = 1.05 x 10−6). (C): In assessing change in BW (% of D1) on D23, unpaired Student’s t-test revealed significantly greater body weight (BW) gain in the males compared to females (t129 = −5.58, *p = 1.39 x 10−07). (D): Palatable food intake (%BW) over binge-like eating training D2 through D18 in F2 females and F2 males. RM ANOVA revealed a main effect of Sex (F1,129 = 4.11, *p = 0.045), indicating an overall increase in PF intake in females compared to males. There was also an effect of Day [Greenhouse-Geisser-adjusted (epsilon for “Day” = 0.74): F3.80,490.43 = 71.32, p < 0.0001); however, the Sex x Day interaction was not statistically significant (Greenhouse-Geisser-adjusted: F3.80,490.33 = 1.98; p = 0.10). (E): Analysis of slope of intake (%BW) from D2 through D18 in F2 females and F2 males using an unpaired Student’s t-test indicated no significant difference (p = 0.10). (F): Palatable food intake (%BW) on D23 (compulsive-like eating assessment) in F2 females and F2 males. Unpaired Student’s t-test revealed significantly less intake in the males compared to the females (t129 = 2.18, *p = 0.03). (G): Time spent on the palatable food (PF)-paired side on D2 prior to binge-like eating training and on D22 post-binge-like eating training. There was a main effect of Day (F1,129 = 14.66, *p = 2 x 10−4) which indicated significant PF-CPP, but no effect of Sex (p = 0.619), and no interaction (p = 0.37). (H): Analysis of the difference in time spent on the palatable food-paired side between D2 and D22 (D22-D2, seconds) in females and males confirmed no significant difference (t129 < 1). (I): Power versus effect size (% variance explained) for an additive QTL model and a sample size of 128 F2 mice (p < 0.05). 0.2, 0.4, 0.6, and 0.8 power is achieved with an observed effect size of 5%, 8%, 10%, and 13% variance explained, respectively.