What does it mean to be fat-adapted?
Fat-adaption is the ultimate goal for ketoers...it’s the next step to extreme success once you’ve reached ketosis.
Just a quick background on why we want to be fat-adapted: our bodies store fat in case we need energy, but as we consume carbs, the glucose from those carbs is used as energy rather than the fat. When glucose is our main energy source and it's constantly being replenished through our diet, it forces the fat we eat to wait it's turn to be used. This is how the fat we eat becomes stored in places like our belly or legs, making us overweight, and putting us at risk for type 2 diabetes (1). Enter: ketosis.
When you restrict the consumption of carbs your body can no longer create glucose to burn for energy, so it switches over to burning fat for energy instead. Once you reach ketosis, your body has made the metabolic shift from burning glucose from carbs to burning the fat from your diet and your fat reserves (2). This can cause consistent and rapid weight-loss-- hello looser clothes and shrinking numbers on the scale!
During the nutritional ketosis phase, be sure to monitor your glucose levels to ensure your levels aren't spiking, throwing you out of ketosis, and inhibiting fat-adaption. The most accurate way to do this, without investing an arm and leg, is to buy a simple blood glucose meter from amazon or a local pharmacy.
In the morning before you have eaten anything, check your glucose levels--ideally they will be 85 mg/dL or less (3). You want to check your levels again 30 minutes AND 60 minutes after each meal. Your goal is to keep your levels between 80-90 mg/dL. If your numbers are slightly higher or lower don't worry, about it, glucose meters aren't completely accurate and as long as you are staying near the 80-90 mark your glucose level is considered stable. Now if you're going over 100 mg/dL, you know you are consuming too many carbs and you need to cut back and consider better food options that won't spike your blood sugar--pass the bacon and eggs please!
ATP and fat-adaption
After about 2-4 weeks of being in ketosis, your system basically reboots itself, enabling your body to use fat and fat stores to produce ketones that can be burned to produce ATP (your body’s energy source) (4). This new metabolic state is called fat-adapted.
Imagine riding a bike for 45 minutes and your body has burned off it's available glucose and it has to turn to its fat stores to provide the energy necessary to keep going. Now imagine that rather than your body quickly switching back to glucose-burn once the exercise is over and you've re-fed it some carbs, your body continues to burn fat at the rate it was when you were exercising. This is what happens when you are fat-adapted (5). Your body is constantly in high fat burning mode as if you were exercising. SCORE!
How to know you’re fat-adapted
Unfortunately, there aren’t any tests you can take to know if you’re fat-adapted. However, there are some indicators to watch for. If you experience some of these, you are likely fat-adapted:
Able to fast for long periods of time without feeling hungry (or hangry!)
Excessive amounts of energy
Improved sleep patterns
Decreased cravings (or none at all!)
Ability to exercise while fasting or ingesting minimal calories and carbs
Ability to re-enter ketosis quickly in the case you go out of ketosis
Sounds amazing right?! Stick to your low-carb diet and you’ll get there. All these awesome results are the reason fat-adaption is the goal--it is the optimal way to utilize all the benefits (6) of ketosis and reach your health and weight goals quickly.
(1) Dara P Schuster. Obesity and the development of type 2 diabetes: the effects of fatty tissue inflammation. Diabetes Metab Syndr Obes. 2010; 3: 253–262.Published online 2010 Jul 16.
(2) Anssi H Manninen. Metabolic Effects of the Very-Low-Carbohydrate Diets: Misunderstood "Villains" of Human Metabolism. J Int Soc Sports Nutr. 2004; 1(2): 7–11.Published online 2004 Dec 31.
(3) Mayo Clinic Staff. Blood sugar testing: Why, when and how. www.mayoclinic.org. https://www.mayoclinic.org/diseases-conditions/diabetes/in-depth/blood-sugar/art-20046628. Accessed Sep. 18th, 2018.
(4) Dr. Jnankumar Chaudhuri. Ketone Body Metabolism. http://www.srmuniv.ac.in. http://www.srmuniv.ac.in/sites/default/files/files/KETONEBODYMETABOLISM.pdf. Accessed Sep. 18th, 2018.
(5) Diego Gomez-Arbelaez, Ana B. Crujeiras, Ana I. Castro, et al. Resting metabolic rate of obese patients under very low calorie ketogenic diet. Nutr Metab (Lond). 2018; 15: 18.Published online 2018 Feb 17.
(6) Linda Stern, MD; Nayyar Iqbal, MD; Prakash Seshadri, MD, et al. The Effects of Low-Carbohydrate versus Conventional Weight Loss Diets in Severely Obese Adults: One-Year Follow-up of a Randomized Trial. Annals of Internal Medicine, May 18th, 2004