The Dreaded "How are you losing the weight" question at work

I struggled with this big time a first, who to tell, who not to tell. Etc... I'm down about 90 lbs since preop and surgery 5 weeks ago, people are definitely noticing... The other day a woman I never even spoke to before came up to me and said I look great! My response when asked how, I'm eating a lot less and focusing on protein and veggies...ALL TRUE! I've shared with many, but I have no issues sharing if asked.

I don't know the right answer because I haven't had my surgery yet so I'm clueless, but all I can remember is when Star Jones had surgery and when people asked she said something like "it's private" or "between my doctor and me", then later, "yes, I did have a medical intervention" or a "medical procedure."  Eventually, she just had to tell people.  She looked kind of goofy to go that route because people can usually tell when it's such a rapid loss.  They'll just gossip behind your back anyway like my family did when my sister-in-law lost weight.  She's my ex-sister-in-law now so I never did get the truth.  I recall when Carnie Wilson had her surgery filmed and everyone appreciated her honesty and told her how great she looked when she was thinner.  People didn't seem to hold it against her.  The catch is when she gained a lot back, she got flack for that so what can you do?  I guess what I'm realizing in writing this is that you can't make people happy no matter what you do so who cares what they think.  I will probably tell them and just let them react how they are going to.  They already choose how to react to the fat so they'll just choose how to react to the thin.  Again, I'm not sure the best way at all so I'll sign off now.  Sorry I wasn't much help; I'm rambling!

I'm really not sure how I'll handle it, actually. I work in medical accreditation and the office is very wellness-oriented, so I doubt it'd be much of a problem.

The handful of people in my department already know, since I've had to plan time away and make sure others can cover some of my stuff. That was just, "I'm going to be out for 2 weeks, I'm having bariatric surgery so I can get off these darn blood pressure meds and stuff. So sad that I'll have to miss the Christmas party!" And that's it, no worries. 

For everybody else... I'm kind of tempted to play it off as a joke, since I'm kind of a goofball. I'm an atheist, so I'm tempted to joke that I sold my soul to the devil. Or since I live in Arizona, I can joke that I volunteered as a drug mule, and it went terribly bad, and a large dose of heroine screwed with my metabolism. Or since I'm a geek, I can say that I'm slowly giving birth to the alien babies that I've been incubating since I started work a year and a half ago?

I figure I'll take it as it comes, and we'll go from there :)