AMcC
Journeyman Pro
Del for what it's worth, I like you had a very inactive job as a sale rep and three years ago went on a health kick.
I downloaded an app called my fitness pal which based on your weight, lifestyle and age gives you a daily calorie allowance abd covers every food out there. You can add exercise and so on to readjust your allowance for the day. According to the app a 3hr round burns 1400 calories and a 4hr round burns 1800
Anyway I used the app to educate me not only of what foods are crap for you but also portion sizes. I lost 2 stone in just under 5 months eating more than I've ever eaten but eating the right foods. You can now link that app to one called pacer which will automatically work out the length of walks and adjust your calories for the day.
A +1 for my Fitness Pal. I downloaded it a while back and started using it recently again. I think it is great, It counts all your calories and tells you what is left for the day. The ability to scan the bar codes from your phone really helps as well. In the beginning it is a bit of a fuss but once you get in to it and start eating the same things again you already have that info saved. I also have a Jawbone UP and that tracks my steps and sleep, but also links with My Fitness Pal.