Pretty sure it's just more protein. You can have either..
55 refers to grams of protein in 5 meals.
70 refers to grams of protein in 5 meals.
Im assuming this goes back to the days where shakes were a larger staple of the Medifast program..
But ya, thats one of the differences..
I have the 55 shakes, my husband has the 70 shakes. There are 20 more calories in the 70 shakes, plus the additional protein..
Duh! I figured that and thought I look at the nutrition, guess not. That makes sense..
I do a lot of exercise so I chose the 70 shakes for the added protein for my workouts..