Breakfast on Wednesday morning is engineer Paul Benigeri's favorite meal of the week. Why? "I haven't eaten in 60 hours," Benigeri tells Business Insider in a sunlit café in San Francisco, after clearing through a frittata with no spinach and extra goat cheese.

Benigeri and his coworkers at Nootrobox, a subscription service for "smart drugs," or cognition-enhancing supplements, are part of a Bay Area group of biohacking enthusiasts called WeFast. The club believes that intermittent fasting promotes longevity, increases focus and productivity, and leads to a healthier diet.

I recently attended the group's weekly breakfast to find out the appeal of starving yourself.