Risks and Benefits to Consider Before Trying Keto

Posted on 07/08/19 by Clint Carter

Maybe you know someone who snarfs down piles of bacon, but thinks toast is evil. Perhaps you have friends who won’t go to dinner after 7, because the time falls outside their “food window.” You might have even seen someone drinking “bulletproof coffee” — regular joe with a pat of butter and some oil mixed in. 

These behaviors are all linked to popular weight-loss programs that share a common approach: to make your body achieve ketosis, a metabolic state that switches your body’s engine from sugar burner to fat burner.

Ketogenic, or “keto,” diets have been around a long time. Conceived in the 1920s as a treatment for epilepsy, they provided the science behind the Atkins diet that first became popular in the 1970s. Now they’re back. Here are answers to questions about how they work and whether ketogenic diets are a sensible approach to weight loss for older people.

What is the underlying theory of ketosis?

After you eat carbohydrates, your blood surges with glucose, the primary sugar that powers all your body’s cells. But when you don’t consume carbohydrates for an extended period — as your ancestors might have done in times of famine — the glucose runs dry, and your liver begins converting stored body fat into W-shaped molecules called ketones. This is the backup fuel system for your body: It is, essentially, running on body fat.

How do you trigger ketosis?

Most proponents point to two approaches: intermittent fasting or following a keto diet.  Many ketosis advocates combine the two methods to one extent or another.

Intermittent fasting attempts to mimic the effects of a temporary famine by limiting one’s food intake to a daily window (usually about eight hours), or by integrating a couple of very-low-calorie days into each week to force the body into ketosis.

Following a keto diet, on the other hand, involves eating primarily fat plus a limited amount of protein (because protein can be converted to glucose) and almost nothing else. “The keto diet is designed to mimic the effect of fasting without actually starving,” says Stephen Cunnane, a professor with the Research Centre on Aging at the University of Sherbrooke in Quebec. “Broadly speaking, they do the same thing.” 

This article originally appeared on AARP.org in July 2019

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