Providing you compliment this routine with a healthy and adequate food intake, then I imagine after about 4-6 weeks you should notice some difference, but this really depends on a lot of things such as your metabolism and can take up to 8 weeks for any particular noticeable difference. For one thing, after a month you should 'feel' much better and more energised.
Remember though that as well as healthy eating and exercise, your body also needs to rest, so don't overdo it.