This has definitely been a trend @Leanne, it isn’t just you. I have looked at some past threads, and found a few older ones that may be of interest to you!
Here they are :Weight gain and ASD closure (diet is mentioned), How are people going years after having your operation? (where @Helen and @Ellen_C mention exercise, and @MissSea had experienced random weight gain), Update on me where @Natasha_HG describes her exercise regime and how things had changed for the better, and Weight gain following closure (more about weight gain experiences).
All the best! We would love to hear updates on this from you all.
-Arjuna from ModSupport