im not sure on the answer either but i would imagine it is to limit the extra calories (albeit not many calories). Having said that, i technically have 2 servings a day as i use one serving of MAM to make my choc tetra mousse and i use a serving of supercook gelatine to make the jelly, and before i looked into the gelatine i was using MAM in the jelly too.it doesnt affect me but i guess if u were having 3-4 mousses a day every day it would mount up over time. ( still not enough to dramatically affect weightloss but it may cause some small differences IMO)
i wouldnt give up my daily trifle for anything though. (give us this day and my daily trifle) lol