I haven't noticed anything to be honest. I expected to get an increase and thus also gain weight because it seems to be a fairly common experience among FTM but I didn't notice any. My apetite from what I've noticed, is by and large, exactly the same except the kickstart I gained when I began to workout for real and my metabolism increased which is a very noticeable change to me because it feels like someone presses on an overdrive button. I really feel the difference from living a sedentary lifestyle.
I did gain weight but it seems to be predominantly muscle mass, not fat. Currently weighing around 57 kg and I'm 160 cm tall so I hope to lose at least 5 kg more fat and see if I've gotten closer to my ideal body fat percentage (10%). It does seem like I burn it off a little easier after starting HRT, likely due to greater muscle mass which means more energy is required to keep the machinery running.