Ketosis has a long list of health benefits. The biggest benefit, and reason why the Keto Diet comes so highly recommended, is weight loss. When in ketosis, we burn fat effectively and efficiently. The reason for this is "fat adaptation," another important Keto keyword.
What is Fat Adaptation?
Fat adaptation is the state in which the metabolism burns fat as its primary source of energy. It's part and parcel with ketosis, though it isn't actually necessary to be in ketosis all the time to be fat adapted. Fat adaptation is an ongoing state. As long as your body is fully adjusted to burning fat instead of carbs, you're considered fat adapted, and you can remain so in the long term by consistently staying low carb.
Fat adaptation is the sweet spot we're trying to reach as Keto followers, so it's helpful to know when we've arrived. With Keto, we "teach" our formerly carb adapted bodies to thrive in the absence of carbs. There are telltale signs that show us we've successfully learned.
#1: You've Been In Ketosis For A While
At the start of Keto, ketosis kicks off within days. If ketosis is sustained, your body will achieve fat adaptation in 4 - 12 weeks. With regular exercise, it may start sooner.
A blood or urine test for ketones can determine for certain if you're in ketosis. Staying there requires a continued adherence to the diet, so if you've been eating the right things for weeks (with close monitoring and no cheating), and you've experienced the typical symptoms of ketosis, it's generally safe to assume you're in it.
The most important thing to remember is that fat adaptation takes a while to get rolling. We're making a major adjustment after a lifetime of relying on carbs, so be patient and be strict! Once fat adaptation is the body's primary operating mode, it's possible to go in and out of ketosis for short periods without losing it. But we have to get there first, and the only way to do that is through solid consistency at the outset.
#2: Improved Energy Levels
In a world where we're constantly bombarded with carb- and sugar-laden treats, it's easy to forget that being fat adapted was -- and still is -- the ideal metabolic state for humans. The human body has evolved to be able to run far better on ketones and stored body fat alone.
When finally fat adapted, we access that primal metabolic state and reap its benefits. Chief among them is energy. Carbs are a less efficient energy source than fat, which is why eating them often results in feeling sluggish or weighed down. Feeling a sustainable, steady level of energy that doesn't require caffeine and doesn't crash is one of the greatest signs (and rewards) of fat adaptation.
#3: Decreased Cravings
Carbs can power us, but in order to keep running, we have to reload on carbs again and again. They're also incredibly addictive, and it's easy to eat too much.
Fat adaptation frees us from the potential for a carbohydrate binge cycle by eliminating our need for them, thereby decreasing our cravings for them. When you reach a point where you're not preoccupied with carbs and you're no longer fighting the urge to snack on them, congratulations! You've likely crossed the threshold into fat adaptation.
#4: Exercise, A Whole New World
While many athletes tend to "carb up" before working out, we know by now that's not necessary. Studies have shown that endurance athletes perform better in nearly every way when they're on carb-restrictive diets.
Not only do low-carb athletes burn much more fat while doing the same exercise as their carb-loading counterparts, they also use oxygen more efficiently and can work out longer. Adjusting to being a low-carb athlete takes some getting used to, but when you're fat adapted, you'll know by the way exercise feels.
#5: You Can Cheat (Some)!
Fat adaptation hasn't exhausted its miracles just yet. One of the most awesome rewards we get from staying in ketosis long-term is the ability to keep on burning fat for short periods of time when not in ketosis.
That's right -- after sticking with strict Keto long enough to reach fat adaptation, we can occasionally eat above our carb limit. The ketone count in the blood decreases when we have the infrequent cheat meal, meaning we're not technically in ketosis anymore. The fat adapted body can recover from being kicked out of ketosis with great resiliency; within less than a day, we're back in and continuing to burn fat. If you're a few months into strict Keto and a slice of cake doesn't throw you off, you're probably fat adapted.
#6: Brain Fog Disappears
Constant glucose consumption puts us in a state of perpetual cloudy consciousness. Sugar is simply not the ideal source for most of the brain -- but ketones are. One of the signs that you've entered ketosis is a short-term impairment of brain function which can include brain fog, forgetfulness, confusion, and dizziness as the brain gets used to ketones.
When we've taught our brains to run on ketones, it disappears and makes way for greater mental clarity than we've ever experienced. Fat adaptation leads to quicker thinking, better sleep, and overall better mood.
To Wrap It UpTo simplify, there are essentially two ways you'll know if you're fat adapted.
The first: You know for a fact you've been following the Keto Diet strictly and are existing in a state of sustained ketosis. This requires commitment and tracking, and only you will know if you've been doing it right.
The second: You'll just feel better! Ketosis and fat adaptation have been available to us as modes of existence since the dawn of humanity, but carb culture has made us forget them. When you've accessed them, there will be no denying a powerful feeling of wellness in every area of your life.