BACKGROUND: Eating behavior changes under stress, i.e. during high HPA-axis activation.
AIM: Assessment of effects of high versus low HPA-axis activation on liking and wanting related brain signaling in relevant regions.
METHODS: 15 female subjects (21.5±0.4 years, BMI=22.2±0.4) completed fMRI scans on 2 days, in a fasted as well as a satiated condition on each day. The days were sorted by HPA-axis activation, resulting in two sufficiently separated HPA-axis states which were statistically confirmed (p<.05). During scans, subjects rated liking and wanting for food images; wanting indicated food choice for the subsequent meal. Energy-intake, hunger and fullness were additionally recorded.
RESULTS: Hunger changed significantly over the meal (p<.001). Energy intake was lower during the second meal (p<.001). Behavioral wanting was lower after breakfast (p<.01), behavioral liking did not change. During low HPA-activation, liking task related signaling (TRS) pre-meal in the anterior insula predicted behavioral liking, wanting TRS in the anterior insula, nucleus accumbens and thalamus predicted behavioral wanting. During high HPA-activation, these relationships were not present pre-meal, but post-meal behavioral liking was predicted in the nucleus accumbens and wanting in the caudate.
CONCLUSION: High HPA-axis activation disrupted and redirected the connection of behavioral liking/wanting with the specifically associated brain signaling in relevant regions.