When Erik Oberholtzer was feeling overwhelmed by the stress of expanding his restaurant business, he decided to go as far off the grid as he could go for three weeks.

Mr. Oberholtzer, co-founder of Tender Greens, a casual, slow-food-minded restaurant with 13 locations in California, left his phone, email and most human contact behind in mid-2012 and went trekking in the Himalayas. "In a world where we are so distracted by everything digital, it's nice to be focused on just putting one foot in front of the other,"...