Figure 2. Behavioural rhythms entrained to a LD cycle are affected by HF.

A, daily wheel-running activity of Arvicanthis entrained to a light–dark cycle (indicated by the top black–white bar) and to a NF or HF at the middle of the night period (vertical arrow). In actograms horizontal arrows on the right indicate transition ad libitum–restricted feeding–ad libitum feeding conditions. Activity profiles of wheel-running activity over the 24 h cycle of NF and HF Arvicanthis (means ± SEM) under food ad libitum conditions (left) and during the restricted feeding period (right). B, representative actograms of wheel-running behaviour in Arvicanthis under AL (left) and HF (right) conditions (ZT-18) during the entrainment to a LD cycle and then released in DD conditions. Arrows on the right indicate the time duration of HF. Group mean (±SEM) of phase delays in AL and HF fed animals after to be released in DD conditions. Linear regression of weight loss (%) plotted against phase delays in HF Arvicanthis (R²= 0.53). *P < 0.05, differences between groups.