90% of weight loss comes from your eating habits/diet. While I'm a huge fan of walking, I love it actually, if you don't change your eating habits no amount of working out (walking, running, cross fit...) is going to make a difference, on the scale at least.
I'm a huge fan of both walking AND eating and I lost 40+ pounds (and maintained it) while doing a lot of both. I changed my eating habits in my late 40s by cutting out a lot of sugar and junk (I was eating a TON of junk and not exercising for a good chunk of my 40s - oops!) but I still eat a lot (more than my overweight husband by a good bit). I walk about 125 miles/month on the treadmill but I keep the speed and incline up the whole time (like 4.3 mph and 8-9 incline). Maybe I'm burning "100 calories" but it certainly seems sufficient to keep up with my appetite. I wish I liked some other form of exercise but I don't - just some ab work and pushups, a few barbell exercises.
I like walking outside for the fresh air and sunshine (well, not this week) but I don't really count that as part of my exercise because I don't ever end up drenched in sweat like I do inside.