Ask HN: What start ups have good health and fitness benefits?

As an avid start up stalker I've noticed plenty of start ups out there offer gym membership reimbursement, healthy snack foods, and various other "keep our employees happy and healthy" benefits. I love that there are so many of these great benefits out there and think that there could be some great value in keeping your employees healthy and therefore happy and productive.

My questions are: -Do your employees take advantage of these benefits? -If so have you seen a good ROI? -What benefit do you offer that your employees love most? -What health/fitness benefit do they want?