My dad lost about 25lbs by tracking activity with a Fitbit, counting calories with the Fitness Pal app, and weighing in daily. I had my doubts when he started into all of this, especially because the entry for Fitness Pal seemed like a inconvenience. However once he got into routine using all three of those things together he was able to get quantifiable results, and it all became like a game to him and he lost weight pretty fast.
Overall he looks like a more respectable dude, says he has less back pain, and seems happier. He's fairly close to his target weight now so he'll just keep on using everything to more or less maintain things. It wasn't that exciting of a process but he pretty much did it with just living say to day life, and walking on weekends.
As far as actual activities go it's a bummer that MTB won't work. Would road biking work at all? It's far less impactful but still enjoyable. Hiking as above would be a pretty good one to, maybe even snowshoeing or XC skiing in the winter.
