Walking in itself will get you to lose weight, but it has to be accompanied by a healthy, nutritious diet. To make it effective however, try walking about 2-4 miles per day.
This depends on your body weight and how many calories you consume a day. You must take in less calories than you burn to lose weight. A good starting point would probably be about 20-30 minutes a day. You will probably want to cut some calories also for best results.
