You forgot to mention the broken bone and resultant time off the bike and on the cake there, boabacca. I know it is only one factor, but it didn't help you, did it?
Out of curiousity, I just plotted my very haphazrd weight over the last few years. I weigh myself very intermittently, when I go to our mum's house and remember to, since she owns scales.
That's roughly 13kg dropped between the 2010 Easter Arrow (the first at which I provided cake and which was the day after me and the EldestCub's first 'big' ride) and the 2010 Dun Run. I rode loads, and tracked calories, and was highly motivated to shed weight so that Wow didn't drop the tandem with me on the back of it and so that I could make it to the end of the FNRttC to Cleethorpes.
Back up gradually when I stopped tracking in the Autumn and over winter up to Christmas 2010, although not to where it was. January 2011 and I started riding winter miles and dropping weight steadily through to the summer. Then a burglary, separation, broken bone and several months off the bike and back up it went.
January '12 and it plummeted alarmingly due to a never before encountered symptom of stress i.e. loss of appetite, verging on inability to eat. Not a recommended method of dropping 8 or 9 kg in a couple of weeks, that - it was really rather unpleasant. I actually started calorie tracking again for a while for the first time since the Dun Run, in order to make myself eat more, and it mostly dropped a bit more steadily for a month or two before stabilising at and around the 100kg mark.
Crept up again over this autumn/winter which isn't surprising given how little I've ridden really. But even now I weigh about 10kg less than I did the day I got my bike. And about 14 or 15 less than at my heaviest, 10 years back.
The 13kg I lost in 2010 was possibly only the second time in my life that I deliberately set out to lose weight and track/monitor what I weigh and what I ate - the previous time was when I was a teenager, and asked the GP to refer me to a dietician. I was quite nervous about the Dun Run mind, and was doing lots of 'training' rides with the Cub before his "Big Ride" to Barrow in Furness as well as swimming lots.
Looking at that graph, it shows me that when I track I lose weight. Or, more probably, when I lose weight I track. Looking back at photos from the last 10 years, I can see that I lose weight when I a) am doing loads of exercise and b) am happy. The happiness and the exercise are very related, I reckon - in a virtuous circle kind of way.
Guess I need to ride m'bike more...