The Nuance
Why Fasting Diets Are About to Get More Extreme
Two weeks without food? Some scientists think it could help.
Every week, the Nuance will go beyond the basics, offering a deep and researched look at the latest science and expert insights on a buzzed-about health topic.
Even if you’re unfamiliar with the nitty-gritty of intermittent fasting, you’re probably aware of its broad strokes. By restricting your food intake a couple days a week (the 5:2 diet) or squishing all your meals into a short daily window (time-restricted fasting), you can lose weight. There’s also mounting evidence that regular bouts of fasting can lower your disease risks, improve your brain function, and even extend your life.
Experts say these diets shift the body’s use of energy in ways that improve cell health.
After going about 12 hours without food, your liver’s stores of glycogen — a form of energy — are depleted, and your body taps into its fat cells for energy, says Mark Mattson, a senior investigator with the National Institutes of Health (NIH) who has researched fasting and its effects (and who practices time-restricted fasting himself). This shift places stress on your cells — mild at first, but more significant the longer you go without eating — that can trigger all sorts…
