you are not alone with this challenge............
the body is a biological engine, it uses and burns what you put in. When you are younger that can be pretty much anything and it doesn't seem to matter but we cannot get away with this as older. Weight loss is calories in being less than calories out - its amazing the junk that creeps in.
Ignoring the exercise bit for a moment, couple of years ago I fundamentally changed my diet, before, lunch was sandwiches from supermarket at my desk, dinner was late, 5 a day was optional, now it's home made, home cooked, (mrs is a star), more vegetables (

), getting good sleep is better,
as to exercise, would agree with comments above, we noticed that actually got worse having moved out of London, before didn't have a car and amazing how much walking /cycling etc do without realizing, now drive everywhere, and impact of less is now very noticeable.
I think having an objective is important, even if its just making sure that when the kids are older and (hopefully) into longer rides that it can be done as a family not staying at home and leaving them to it.