If you eat less than you burn, you will lose fat. If you aren't active or eat WAY less than you burn, you will also lose muscle. I used to be "naturally thin", then I had kids. Looking back, before the kids, I used to walk miles a day. 2 miles one way from the parking lot to classes in college, a half hour here and there between classes, after dinner, bored and nothing on TV. I used to think I really hadn't changed my activity level, I've never been able to run or been interested in sports. But the kids won't walk for miles and miles or spend an afternoon just wandering through the neighborhood. I never broke a sweat, just did it b/c I liked it. Hindsight being 20/20, I think now it's the (absence of) walking responsible for this slow creeping weight gain.
If I keep starting over, eventually it will stick, right?
Current weight: 140
Goal weight: 135