So, all of the weight loss magazines and advice columns say that walking burns just as many calories per mile as running but it takes longer since you aren't going as fast. They are liars. Liars, liars, liars.
Since I hurt my knee, I've been run/walking or just walking instead of running. Keep in mind that I am walking as fast as I possibly can and running when my knee doesn't hurt. Regardless, according to my Garmin, I burned approximately 225 calories (one darn cookie) when running 3.25 miles at an 8.5/9 minute per mile pace. For the same route at an 11.5 minute per mile pace, I burned only 60 calories (one starburst). Yes, Garmin might be wrong - and he probably is, a little.
However, in my completely non-scientific and un-controlled experiment of one, I've noticed the same thing. When running the 9-12 miles per week, I can eat whatever I want (within reason), consume multiple beers and snack on nuts several times daily and still lose weight. While walking, I've cut down on the beer and limited the nuts, but now I'm gaining. I'm not so worried about the weight - big deal. If I would resist the snacks and eat more fruits/veggies, I wouldn't gain anything but what a disservice this hype does to those who are really trying to lose! It makes me hate the dieting "know-it-alls" as much as I hate the childbirth ones. Bastards.
Oh, and - the endorphins. Not being produced so much with the walking, as you may have noticed.