Your Body on Keto
The keto diet works differently than other weight loss plans. Most diets work by cutting calories; so while you do lose fat, you also lose muscle. But keto is less about reducing caloric intake, and more about changing it.
"Studies show that when you follow keto's precise macro blend of 75% fat, 20% protein and 5% carbohydrate, the majority of weight loss is from fat mass," explains Pam Nisevich Bede, M.S., a dietitian with Abbott.
But how does this magic equation turn your body into a fat-burning machine? Typically, the body turns to carbohydrate (in the form of glycogen) for energy. When you cut carbs and increase fat in your diet, the body begins to use fat for fuel instead. This fat-burning state, called ketosis, generates byproducts known as ketones, which help suppress appetite, making it easier to eat less.
What Is a Cheat Day?
For many people, one of the hardest parts of going keto is saying goodbye to their favorite high-carb foods and drinks. But is it OK to occasionally stray from the strict plan? For the most part, it turns out: the answer is no.
"When you go off the keto regimen, it interferes with ketosis and it can take several days to get back on track," explains Bede. "One of the most important factors when it comes to being successful on a diet—any diet—is adherence. So if a little cheat here and there helps you stick with the diet in the long term, go for it. But it's important to limit the extent-the length and the severity-of that cheat day so that you can get back to your usual keto diet foods and the benefits of ketosis as quickly as possible."