As trendy as it is, the Keto diet is nothing new. It’s been used in clinical settings for years to treat some medical conditions, and low-carb diets in general have been around since the early 1970s and the Atkins Diet. But does Keto really work? And, more important: is it healthy? It definitely can be, with a few simple fixes.

What It Is

The Keto diet—short for “ketogenic”—is an ultra-low-carb regimen designed to shift the body into what’s called a state of ketosis. Most of the body’s cells use blood sugar (derived from dietary carbs) as their main source of energy. If carbs are restricted and sugar’s not available, the body starts breaking down stored fat into chemicals called ketones—that’s ketosis. It usually takes two to four days of eating fewer than 50 grams of carbs a day for the body to shift. The intended result: more balanced blood sugar and rapid weight loss. Other research also suggests that the Keto diet may influence appetite-control, and ketones themselves are thought to suppress appetite.