I've lost so much weight over the last three years that I went from "too embarrassed to be seen shirtless" to "slightly above underweight". I did this entirely through eating less food. It's possible dog walking helped, but I keep losing weight even when my dog's at my parents' for a few weeks. By now I may have to eat a bit more since I tried to replace my wardrobe of size Small shirts only to find the stores here don't even have XS. But overall weight loss has gone so well that I'm proud of the result. Some friends and family have expressed concern, but it's not like I go hungry or skip meals, and I think it's because moderately thin people are rare here these days.