Just got back from my 11 day German cycle tour where I was eating whopping breakfasts, cake, big evening meals (Schnitzel, pizza) and then having 100g of chocolate for dessert. Healthy, me.
Anyway, I lost 2kg-ish. Which I could tell before I stepped on the scales as my trousers were loose.
I think the main reason to account for this was that I had whopping breakfasts and consequently didn't snack at all during the day on rubbish like biscuits (which I often do at home). I felt full up until lunch, at which point I usually only had soup or something light. I know people say that eating a good brekkie is good for diet but I'd never really experienced this before - and it wasn't as if my mileage was vastly more than normal. I tend to do 33 miles per day - on the tour I was doing 40-70 so more, but not loads more.