If you're young, just walking might not do it. If you've been completely sedentary, doing anything that adds movement will help, but again, if you're young, you might want to look into something more vigorous than walking. As far as diet, what you want to do is change your metabolism in two ways -- exercise and eating healthy foods gives you energy and burns energy, and second, eating foods that don't metabolize quickly into sugar and that you digest well will keep things moving instead of sticking around. Personally, I think your diet is overloaded with dairy, which isn't digested well by most humans, but some people do lose weight eating a lot of it. That doesn't make it healthy to eat it, as there are a lot of inflammation and digestion problems and problems overloading with calcium causing magnesium problems, but you can still lose weight eating it. Personally, I believe in a balanced diet with only a moderate amount of animal protein -- meaning complex carbs such as whole grains for stamina, enough protein but not overdoing it as it can help with short-term weight loss but isn't the healthiest way to eat long-term, and lots of different colored veggies. But diet is a variable thing -- the one you've listed might just be perfect for you provided it's not so low-calorie you're not getting sufficient nutrients. Nobody knows what the ideal diet is, we only know by looking at people over long periods of time who seems to do better both with health and with weight and even then it's a generalization, as some within the group will do much better than others within the group. Try it and see how it goes.