faye12, my understanding of E and D is that the difference is in the shoulder and hip measurements. E's shoulders and hips are about the same width. D's hips are wider than the shoulders. Both body types are plus size, and both may have undefined waists.
soularchitect, your basic body shape doesn't change, but if you gain weight and wear plus-size your profile type would probably change. The B shape usually becomes an E when you gain weight, and a C can change to the D. This isn't a hard and fast rule, as every woman carries their weight differently. Some of the guidelines and tips for an E would probably help a B with a tummy issue, but her suggestions for the E clothing would all be in plus sizing. I guess it takes a lot of trying on to see what works best for you.