In December, on the day after Christmas, an entire segment of Good Morning America was devoted to intermittent fasting.
Pioneers of human longevity science have long embraced the eating pattern, which they sometimes refer to as caloric restriction. Ingest less food, they say, and the body shuts down a crucial pathway for regulating cellular metabolism, putting cells into repair mode. The thinking is that humans age less quickly while cells are shoring up their defenses instead of growing and dividing.
Now a diet favored by people questing to live longer was getting airtime on a popular morning show. The message was clear. Intermittent fasting is no longer just the purview of folks like Jack Dorsey, the Twitter CEO who outlined his strict eating regimen during a podcast interview last year, revealing he doesn’t eat until 6:30 p.m. each day. The diet has broken into the mainstream. Last year, intermittent fasting was the most-searched diet on Google.
While some fasting diets are in the service of weight loss, the way intermittent fasting is often applied in the corners of Silicon Valley — where it seems to have cultivated an early following — falls under the rubric of mental clarity. Much like dunking butter in a cup of coffee or eliminating everything except animal protein on your dinner plate, fasting is another tool being used to boost brainpower throughout the day.
“[T]he first two weeks were really hard. … [A]fter I got over those first two weeks, during the day, I feel so much more focused,” said Dorsey last spring. “I think it’s just this very ancestral looking for where the food is. You have this very focused point of mind in terms of this drive.”
But there’s another side of this quest to optimize the self. What Dorsey characterizes as focus is what a nutritionist might call starvation, a darker psychology that concerns eating-disorder specialists and therapists alike. The eating pattern is backed by science, but it still raises concerns among some medical professionals.
“These fad diets have become another way to rationalize and legitimize disordered…