I'm with Dogma, one of the things that really attracted me to Medifast was its association with Johns Hopkins. But, as far as differences go, here are a couple that I see:
The WonderSlim website wrote:Our weight loss plan uses portion-controlled meal replacements, provides a minimum of 1,000 calories per day . . . They provide 1000-1200 calories/day for Women, and 1500-1800 calories/day for Men
Whereas Medifast keeps us between 800 and 1,000.
The Wonderslim website wrote:Take 1 multivitamin and drink at least 8 cups of water or non-caloric beverage daily.
On Medifast, we get enough vitamins, etc. in the meals, that we don't have to take any kind of supplement. We can if we want to, but it's not mandatory. That suggests to me that the WonderSlim products are not up to the same nutritional standards as Medifast. Also, we're not allowed to substitute "non-caloric beverage" for our water intake.
The WonderSlim website offered no evidence of research done with their particular products. There was no WonderSlim nurse I could call to answer health questions. The links to the details of the products were broken, so I couldn't even get the nutritional content or an ingredient list. What kinds of sweeteners do they use? Just how much sugar is in them? It was a very brightly colored website, but it just didn't have much depth of information. It may be my closet paranoia, but I'm going to stick with the stuff that has been run through clinical trials at Johns Hopkins, and makes available a nurse AND a doctor for health questions.
And the thing that makes me really skeptical, is this:
The WonderSlim website FAQ wrote:As a result, you’ll not only experience rapid weight loss, but you’ll be doing it in a way that is healthy and will ensure you keep the weight off for the rest of your life.
I believe the ONLY person who can determine whether or not my weight will stay off is me (barring medical problems, of course). I've seen fad products/programs make this claim. Medifast doesn't. They offer help and support and guidance for maintenance, but they never promise that you'll "keep the weight off for the rest of your life." I don't see how any product/program could ever truthfully make that claim. That's like saying, "This product will ensure you quit smoking forever!" I think the only product that could make that claim would be super glue designed for lips. Otherwise, it's up to the individual to follow through.
Just my 2 cents, based only on looking at the website, my instinctive skepticism of most marketing, and my slightly biased (I may as well admit it) loyalty to Medifast.