So this woman I know has gone on this Medifast bullshit diet and lost 40 pounds. Deep down I know she's not going to keep that weight off (since she doesn't exercise, for one), but I can't think of any specific criticisms aside from, "It's forcing you to eat certain foods you have to pay for. Can you do that forever? No."

Need specific reasons why this diet is shit so I can point her in the RIGHT direction. Weight-loss? Good. Laziness and inevitable weight-gain? Not good.