This would really defeat the purpose of personalized recommendations. The test account was for a quick look at what we offer, not as a long-term solution.
Not really. What you do is create a temporary account for each session, unless one exists already. If the user chooses to create an account later, it is not really created, but the temporary account is promoted to a permanent one, and the details like username are filled in.
Unlike stackoverflow.com the food recommendations generated by Usable Health are dependent on each of the answers in the sign up process. For example someone who weighs a 100 pounds will receive different recommendations from someone who weighs 200 pounds so unfortunately there is no way of getting around the complete sign up / nutritional profile creation process.
Again, check out stackoverflow.com. They do this.