Cucumbers have always been cool. Now, thanks to social media, they're also hot. Viral cucumber recipes racked up millions of views in the past year, thrusting the salad bar staple into the spotlight.

They are at least 95% water, he said. That can help with hydration, but it also means cucumbers are a low-calorie vegetable, with only 45 calories a cuke. "You could eat cups of them, and barely ...