Weight loss is more complicated than calories in calories out. Your diet will be the number one thing that leads to healthy weight loss. Eat natural foods with very little if any processing. Avoid sugar and white flour like the poison that it is. If you are completely sedentary then walking will help to a point. Once walking a mile gets easy, don’t assume that two miles will give you a new benefit. Exercise should have elements that push you to your edge, because that is where the body begins to change itself. Try sprinting for as long as you can then walk until you catch your breath and cool down a bit, then do it again Throw in some push ups or jumping jacks, move in every way you body can. Walk or run stairs one day then hills another. There are no magic exercises it all boils down to intensity. However long slow cardio (like walking or jogging) will eventually lead to repetitive stress injuries, just ask any long distance runner.