Let me first say that fat fasting should be used in two situations only: - Breaking through a two week or longer weight plateau. - Inducing yourself into ketosis quicker, whether you are just starting keto or you had a cheat day (1).
If you’re the type of person that loses weight easily and you are NOT hitting a plateau, then fat fasting should NOT be used. It may be potentially dangerous for someone that is not metabolically resistant, or for someone that is not on a plateau (2).
You should not fat fast consistently. Like I said, it is only for people starting a ketogenic diet and want to be inducted into ketosis faster, or for people that are on a long (two weeks or more) plateau.
Understanding the Fat Fast: Lacking carbohydrates and protein will allow your body to depreciate your glycogen supplies quicker, also allowing your corpus to go after the fat stores, like we want it to, to use as fuel.
Fat fasting will force lipolysis, so that fat stored in the body is burnt up (2).
Lipolysis is a process involved in the breakdown of fats, transforming triglycerides into glycerin and free fatty acids. The longer you fast, the more of these free fatty acids are released. Why is this important? Well fatty acids are used by the liver to create small amounts of ketone bodies, and used as fuel.
Lipolysis cannot happen if there is a a large amount of glucose intake, but since 80% – 90% of your food intake is fats, you won't have to worry about excess protein or carbs converting into glucose.
What the Fat Fast Is: So, what exactly is a fat fast? It’s eating between 1000 and 1200 calories a day, where between 80% and 90% of your calories come from fat, and fat alone. The 1000-1200 calories are broken up into 4 or 5 meals a day, eating in blocks of 200-250 calories per meal.
It is normally done for 2-4 days, but is never recommended to go for more than 5 days. Going longer than this will start to put your body in “starvation mode” and your muscle mass will be metabolized as energy (3) – the exact opposite of what you want.
Hungry? You may be at first, but once your body adjusts to this new way of eating, you will notice a drop in hunger. This is because you will be eating in frequent intervals and consuming high amounts of fat, which increases satiety levels.
If you’re doing a fat fast, I recommend a 3 day fast. This normally drops approx 5-8 pounds of body fat and water weight. When you enter back into a regular diet, expect to put back 2-3 pounds of that weight.
What to Eat: So let’s get to it. What should you be eating? Well that’s up to you. There’s not all that much choice, as you have to maintain low calories and high fats.
Here are some selection for single meals: - 1 oz. macadamia nuts - Macadamia nut butter with 2 oz. cream cheese - 1 oz. chicken with 2 tbsp. mayonnaise - 2 egg yolks with 1 tbsp. mayonnaise - 1 cup coffee with ¼ cup heavy cream - 4 slices bacon (be careful with this, as it dwindles under 80% calories from fat) - ¼ cup heavy cream whipped with Da Vinci flavored syrup - 2 oz. sour cream with ½ cup cucumber - ½ Serving of sugar-free Jell-O with ½ cup whipped cream
Feel free to mix meat in there, but be careful about the amount eaten. As most of it will have large amounts of protein, you should be sparing. Chicken, tuna, turkey, bacon, prosciutto, etc. are great ways to add protein to your diet.
Making It Easy: If you’re unlike me and just love cream cheese, then you tins snack on a full 8 oz. block of cream cheese for the day along with a cup of coffee with 2½ tbsp. coconut oil in the morning.
A block of cream cheese with a ketoproof coffee is one of the best policies to do a fat fast, as it is: - 1020 Calories - 97g fat (86% calories from fat for the day) - 8g Carbs (3% calories from carbs for the day) - 16g Protein (6% calories from protein for the day) - Easy – one of the most important factors. Drawbacks: Drawbacks are more of a personal note from me. I just want to be sure to reiterate that a fat fast can be potentially dangerous if you are not at a weight plateau. Again, ONLY do a fat fast if you are wanting to be induced into ketosis faster, or if you are at a long-term weight deprivation plateau of two weeks or longer.
(1) Vazquez, J. A., & Kazi, U. (1994). Lipolysis and gluconeogenesis from glycerol during weight reduction with very-low-calorie diets. Metabolism: Clinical and Experimental, 43(10), 1293–1299. https://www.ncbi.nlm.nih.gov/pubmed/7934983.
(2) Michelle, K. (2017, July 18). The fat fast diet. Retrieved September 3, 2018, from https://www.livestrong.com/article/320892-the-fat-fast-diet/.
(3) Manninen, A. H. (2006). Very-low-carbohydrate diets and preservation of muscle mass. Nutrition & Metabolism, 3(1), 9. https://doi.org/10.1186/1743-7075-3-9.