I have done both Medifast and Wonderslim. Wonderslim has the advantage of better taste, but some of their products are vitamin deficient. Just read the labels and choose the vitamin fortified products, if you plan to follow Wonderslim.
I lost weight on both diets, but having not changed my lifestyle, I regained the weight back, faster than it took to take the weight off. I follow Jenny Craig now, for its more 'normal' eating patterns and foods, and I am learning portion control, better food choices, etc.. Sure, the weight loss is slower, but this is a good thing. I am a senior, and plan to remain a Jenny Craig client for the rest of my life. For me, the eating plan, and direction is invaluable. Remember, gimic diets are just that--quick fixes. I do wish success to everyone in their weight loss journey, no matter what plans they follow. JMHO.