My Fat Fast Experiment and Meal Plan
Martina SlajerovaThis post may contain affiliate links, see our disclaimer.
A few weeks ago, I created a guide to the Fat Fast. This short-term diet plan is very popular within the low-carb community because it may help people break through a weight loss plateau. I have always been planning to try the fat fast but was discouraged by its stringent rules and so I made some adjustments to it. Here is how my fat fast experiment looked like:
- Eating 2-3 regular meals (plus coffee). Ever since I've been following LCHF, I got used to 1-3 meals a day (plus coffee). Eating many small meals (4-5 as recommended in the traditional fat fast) would only make me hungry and think about food all day long. Eating 2-3 regular meals was more convenient.
- Sometimes eating less than 80% calories from fat. Getting 80-90% calories from fats is more difficult than you may think. I've reviewed all the available studies on the fat fast and there is no evidence that it is more effective than other types of low-carb diets limited in calories. That's why my tweaked version allows to go slightly below 80% fat but it is still relatively high in fat compare to "regular keto eating."
- Eating close to the upper limit of calories allowed on the fat fast. Limiting your food intake to only 1000-1200 kcal could be quite tough. On average, I ate 1100-1200 kcal. I was a bit hungry during the first two days but it was bearable. My body got adjusted to lower food intake very quickly and I naturally kept my calorie intake low even after the fat fast (1500-1600 kcal compared to my regular ~2000 kcal).
- Following the fat fast for no more than 3-5 days. According my tweaked version, I had no difficulties following the fat fast for 5 days. In fact, I know I could do it for even longer but didn't want to run any risks of deficiencies or getting my body into a starvation mode.
- Including some type of exercise. I didn't experience any drop in energy. In fact, I could do lifting and even some high intensity interval training. During the period of 5 days, I didn't give up my daily 30-45 minute walks, had 2 days of weight training (20 minutes which I mostly do at home) and one day of HIIT (20 minutes).
- It's hard to get all your electrolytes on a very low-carb diet limited in calories, so I included foods rich in electrolytes (avocados, nuts, mushrooms and even dark chocolate). You can always take multivitamins, magnesium supplements and for your potassium use a pinch of lite salt together with regular salt.
Ketone & Glucose Monitoring
I started using blood ketone meter during my fat fast. I've been using urine ketone sticks to test my ketone levels every now and then and to monitor my tolerance to carbs. However, I wanted to get a more accurate idea of how my body was affected. Another more convenient and less expensive option is to use the Ketonix Acetone Breathalyzer. While you can easily get both the urine strips and blood ketone meter from Amazon, the breathalyser is now only available at the manufacturer's website.
My readings very high from day 1, going up to 3.2 mMol (right) while my glucose levels stayed low (4-6 mMol, left). Both of the values shown below were my morning fasting levels. It's very likely my ketone levels were even higher later in the evening.
During my fat fast experiment, I had no symptoms of keto-flu, because I was already keto-adapted. If you just started following a low-carb diet, you will need to give it at least 3-4 weeks before your body gets used to using ketones for fuel and you should not follow the fat fast (try this diet plan first).
My Progress
Although I never had to lose a significant amount of weight, I have always been struggling with 2-4 kg of excess body fat. Don't get me wrong, I have a healthy weight but simply wanted to shed a few more pounds. I'm physically active and eat 30-50 g net carbs a day (you can read why I don't eat less carbs in my post here.) I've always had a big appetite and hormone issues (Hashimoto's) since 2011 which makes weight maintenance / weight loss more difficult.
Also, as I mentioned in my post here, weight loss becomes more and more difficult as you get close to your target weight. Unfortunately, I'm not one of those who can eat huge amounts of calories on a low-carb diet without consequences. One day of excessive eating won't make a difference but what really counts is how much you eat on average, say over a week.
Being a food blogger, I spend a big part of my time developing recipes and I'm constantly surrounded by food. I don't count calories but I am always aware of how much I eat. No matter what diet you follow, you can eat too much and put on weight, especially if you eat too many treats (even low-carb treats). Low-carb eating has a natural sating effect but this may not be enough for everyone. To find your ideal food intake, try KetoDiet Buddy, our free online keto calculator.
Before the fat fast, I was at 60 kg / 132 lbs (~ 22% body fat). My target was to get to 56 kg / 124 lbs which is a lot in just a few days. During the 5 day fat fast, I've lost about 6 pounds and gained 2 pounds back after 2-3 days. So, I'm happy with the final result, 58 kg / 128 lbs. I used body callipers to measure my body fat and confirmed that all of it came from body fat - no muscle loss!
Another effect of the fat fast was that my appetite decreased and all sweet cravings disappeared completely. Without forcing myself, I started eating less than before the fat fast and I got better at portion control.
I was using the KetoDiet iPad app to track my diet. I was keeping my fat intake between 72-83% calories from fat, mostly round 80% and my calorie intake round 1,100 kcal.
My Diet Log in Detail
I included raw dairy in the fat fast. There are many recipes with or without dairy among those I created for the fat fast.
You can always use coconut milk instead of cream (Aroy-D tastes just like cream!), ghee instead of butter and avocado in salads instead of cheese.
Day 1
- Meal 1: 2 oz / 60g macadamia nuts, 1 avocado (7.1 oz / 200g) seasoned with pink Himalayan salt (you can get a large bag of macadamia nuts here).
- Meal 2: Sashimi (80g salmon + 20g tuna) with some seaweed and edamame beans (sushi takeaway). Edamame beans are low-carb and paleo-friendly but you can skip them.
- Snacks: 2 cups of coffee, each with 2 tbsp heavy whipping cream, herbal tea
- Exercise: 35 minute fast walking
Total Daily values: 1138 kcal, 83% kcal from fat
32 g total carbs, 20.2 g fibre, 11.8 g net carbs (4%), 35.8 g protein (13%), 102 g fat (83%), 463 mg magnesium (115% RDA), 2185 mg potassium (109% EMR)
Day 2
- Meal 1: 1 slice bacon, 2 large eggs fried in 1 tsp ghee, 2 roasted tomatoes (5.3 oz / 150g), 1 small gluten-free sausage from outdoor-reared pork (1.8 oz / 50g)
- Meal 2: Beef burger served on half of my keto buns (recipe from my apps and book), 2 small lettuce leaves, 1 tsp home-made mustard
- Snacks: 1 cup coffee with 2 tbsp heavy whipping cream, 0.7 oz / 20g dark chocolate (85% cacao), 1 oz / 30g macadamia nuts, herbal or green tea
- Exercise: 45 minute fast walking
Total Daily values: 1107 kcal, 78% kcal from fat
21.5 g total carbs, 9.7 g fibre, 11.8 g net carbs (4%), 49.6 g protein (18%), 94.4 g fat (78%), 289 mg magnesium (72.4% RDA), 1499 mg potassium (75% EMR)
Day 3
- Meal 1: 3 slices bacon, 1 small avocado (3.5 oz / 100g), 1 cup brown mushrooms (90g / 3.1 oz) cooked in 1 tbsp butter, salt to taste
- Meal 2: Tomato & feta salad from 3.5 oz / 100g tomatoes, 2.8 oz / 80g feta cheese, 1/2 cup black and green olives (2.8 oz / 80g), 1 tbsp extra virgin olive oil, basil or oregano to taste
- Snacks: 1 cup coffee with 2 tbsp heavy whipping cream, herbal or green tea
- Exercise: 30 minute fast walking, 30 minutes home exercise (a combination of HIIT and strength training). I often follow videos from BodyRock. If this looks too challenging (or too easy) for you, they have more videos for beginners / very advanced.
Total Daily values: 1155 kcal, 85% kcal from fat
22.4 g total carbs, 11.2 g fibre, 11.2 g net carbs (4%), 30.6 g protein (11%), 107 g fat (85%), 194 mg magnesium (49% RDA), 1583 mg potassium (79% EMR)
Day 4
- Meal 1: Salmon & cream cheese parcels (ready-made from M&S) with 1/2 avocado (3.5 oz / 100g) seasoned with salt
- Meal 2: Slow-cooked meat (lamb, 6 oz / 170g) with butter-roasted asparagus (1 tbsp butter, 3 oz / 85 g asparagus), salt
- Snacks: 1 cup coffee with 2 tbsp heavy whipping cream, herbal or green tea
- Exercise: 35 minute fast walking, 20 minutes home exercise (strength training - squats, press-ups, etc.)
Total Daily values: 1049 kcal, 75% kcal from fat
15.6 g total carbs, 8.5 g fibre, 7.1 g net carbs (3%), 57.3 g protein (22%), 85.5 g fat (75%), 199 mg magnesium (50% RDA), 1409 mg potassium (71% EMR)
Day 5
- Meal 1: 1 large egg fried in 1 tbsp ghee, 1/2 avocado (3.5 oz / 100g) seasoned with salt, 1 medium gluten-free sausage from outdoor-reared pork (2.8 oz / 80g)
- Meal 2: Omelet from 2 large eggs fried in 1 tbsp ghee topped with 5.3 oz / 150g slow-cooked lamb and 1/2 avocado (3.5 oz / 100g) seasoned with salt
- Snacks: 1 cup coffee with 2 tbsp heavy whipping cream, herbal or green tea
- Exercise: 45 minute fast walking
Total Daily values: 1054 kcal, 81% kcal from fat
15.3 g total carbs, 10.5 g fibre, 4.8 g net carbs (2%), 44 g protein (17%), 92 g fat (81%), 206 mg magnesium (67% RDA), 1499 mg potassium (75% EMR)
I've been making easy to prepare recipes (you can find all of them here) during my fat fast experiment and even ate out on the first day (sashimi which is my favourite sushi meal). For those who have my apps / book, there are many recipes suitable for this diet plan, too.
We have been working on yet another update and are planning to add a filtering option to search for meals based on special dietary requirements which will include meals suitable for the fat fast.
How about snacks? Apart from coffee with cream or tea, other snacks great for the fat fast are fat bombs such as the Dark Chocolate Raspberry Fat Bombs (photo below).
Final Thoughts
Fat fast is not suitable for everyone, you really have to be keto-adapted before you even try it. However, if you are stuck at the same weight, then it can definitely help you move the scales down and help you start losing weight again.
You may also like
Complete Guide to Fat Fast
7-Day Keto/Paleo Diet Plan
2 Week Ketogenic Diet Plan
7-Day Grab & Go Keto/Paleo Diet Plan
2 Week Grab & Go Keto Paleo Diet Plan
2 Week Vegetarian Keto Diet Plan
Why Pairing High-Protein Keto with Fasting Is the Game-Changer You Need
Thriving on a Budget: Your Ultimate Guide to Affordable Low-Carb Living
Beyond the Labels: A Fresh Take on Keto and 'Non-Keto' Foods
How to Stay Low-Carb and Keto When You Travel
How To Low Carb: 15+ Common Weight Loss Mistakes
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The Ultimate Keto Food Swap List: How to Swap Common High-Carb Foods for Healthy Low-Carb Options
How to Stay Low-Carb and Keto on a Budget
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Comments & ratings (86)
Hi Martina! Happy New Year to you, sweetie! Given the latest information from Dr. Jason Fung, regarding pure water fasts and extended fasting as strategies which do not decrease metabolism and cause muscle catabolism, what are your thoughts on Fat Fasting for extended periods just a wee bit beyond 5 days? I know that Dana Carpenter in her “Fat Fast” cookbook, said that she went on some for a week and one for eight days with no ill effects, stating that Dr. Benoit fasted his subjects for 10 days. She also quotes Dr. Jackie Eberstein as saying maybe to go up to 5 days of fat fasting, followed by 2 regular low carb days....I am wondering if a person could for example, follow Dr. Jackie Eberstein’s adivce, but then do another shorter spurt (say, 3 days after several days of regular eating) and simply rotate this idea. Another scenario: One 5 day Fat Fast, 5 day regular low carb eating, 3 day Fat Fast...and continue to rotate until one has achieved a significant progressional loss of body fat. Possibly even just 2 cycles of this one rotation. -I have a great interest in this topic, due to the increased information about extended water fasts as indicating NO muscle loss and an increased metabolism. Wondering why fat in itself, should lower metabolism, if at all. In the meanwhile, I am on a hopeful 5 day fast and simply pondering these things. -I love how you laid out the Fat Fast in many adaptable ways! ❤️ You rock! Wishing you a Happy New Year from Canada! Sincerely, Mary
Thank you so much Mary and Happy New Year to you too! Thank you so much for your kind words ❤️
I personally don't do extended fasts (due to a thyroid condition) and I don't think that extended fasting is that similar to fat fasting. For fat fasting I wouldn't (personally) go beyond the recommended 3 to 5 days. Given the anecdotal evidence of this approach, it's a safer approach - that is just my opinion.
The question is what are you trying to achieve? What is your goal? Unlike extended water-only fats which are typically used for several different reasons (7 Science-Backed Health Benefits of Fasting), fat fasting is usually used for weight loss.
I hope this helps!
Good post on fat fast and challenge the very concept of weight loss using specific food. Essentially it is a caloric-restriction plan - fat happens to be the main fuel within this calorie restriction so there are plenty of food outside of eggs that has over 40% calories from fat.
While I applaud the confirmation of the pounds lost comes fat using a caliper, why then is there no explaination of the weight regain? Is the regain from fat or is it additional water retention? Since you mentioned all the weight loss was from body fat, not muscles, I assumed that statement means none of the weight loss came from water. So what explain the fat regain or new water gain post-fat fast?
Is there a follow-on weight and body fat monitoring well after the fat fast (1 week after, 2 week after) to monitor after you have adjusted down from 1600cal to 1200 cal as your normal daily calorie intake, was there any weight rebound back to pre-fat fast? This shall address the question if a fat fast is useful in the long term, or is it useful to drop a few pound before attending a party and fit into a dress better.
Overall I find your content very useful and have an unbiased perspective - it is void of false statement and false advertisement of what keto can do. In this day and age of over-information and dis-information, what readers could use is something more blunt - deliverying hard to swallow truth in the fewest words. Overeating in any diet result in weight gain, keto or not.
Great info. Thanks. I've been keto adapted for a few months now and loving it. I've found that my ketone levels drop low even when I'm strict on the plan and even sometimes when fasting. Interestingly I found that my levels when higher the morning after going out with friends and eating some new foreign foods like meat that was marinated in soy and sugar and different sauces and other foods, still trying to adhere to keto. It was as if going slightly astray, even if it was just in trace amounts of sugars and carbs, actually boosted my levels incredibly high the next morning, much to my surprise. Has anyone else had a similar experience? Is there such a thing as being too strict on the keto diet? If so I think that may be something I do.
Hi,
I really like this blog, good job.
I wandered if you also have a KETO Meal Prep Menu ?
It would really fit in my live, because every day I have so little time to make a decent breakfast, lunch or dinner.
I would really appreciatie it.
Thank you
Kind Regards
Betty
Hi Betty, you can download our free diet plans: ketodietapp.com/free-diet-plans
They are optimised for busy people (meals are prepared in advance for the rest of the week so you don't have to cook every day).
Day two meal one, you say a gluten free sausage??? Unless you had it stuffed with grain, why do you identify it as gluten free? Gluten is never found in any meats. It is only found in some plants like wheat, rye, barley...
lloyd,
www.bentmileshealth.com
There are fillers such as corn starch or flour in sausages - it's always better to look at the list of ingredients.
Love this! Am really stock on my weight and I was trying to find something like this! Thanks for sharing !
Question:
1-can a do 2 big Snacks ( coffee and WHC ) and 1 Meal?
2- And you said you gain 2pounds later, why that happen?
Hi there, really good blog.
How much weight did you lose during the 5 days?
Hi Gemma, it's above in the "My Progress" part 😊
VERY nice blog and recipes! Thanks for sharing, Martina! 😊
How do I make the salmon and cream cheese parcels or something similar at home?
I think it was just smoked salmon, herbs (dill works well) and lemon juice so it should be easy to make them 😊
I need to loose weight can u share me a good keto diet plan to shed off weight ASAP.
You can get my diet plans: ketodietapp.com/books (they are ideal for weight loss) - for free diet plans, scroll down that page. I hope this helps!
Today is 3/13/2018 and I am just now getting off a 5 day 800 cal. for 3 months fasting.I feel great,but my #'s still stay up in the 300 range.I was on 3 different types of diabetic meds. that would not get the #'s out of the 300 range,even up to 700 or more as my meter reads high on those days when[b][/b] I wasn't watching what I was eating.After getting myself off the meds. I even had my #'s in the 200 range something the med.s could not do.After research and research I came across DrAxe.com such an amazing man and I noticed that what I was eating was causing a lot of damage.Foods like rice,noodles,popcorn,breads of all kinds,beans REALLY! Oh yes,beans would sky rocket my #'s and fruits,go figure! I will say I have a strong will power when it comes to food as I am not a big eater at all it was just what I was eating that a normal person could eat and not effect them at all, like my hubby! Oh yes, dear old hubby can scarf down all kinds of high carbs,high calories,foods high in GI and I checked his #'s they were 98 on my meter,say what??? My dad who is a diabetic as well been normal weight all his life can take his meds. and be in the 90 range.My dad's mom died of diabetes in her 60's so genetics plays a part as well,not good! I had very large 8 boys at birth and was diagnosed with 6 of them GD. I struggled with weight loss for all my married 35 years, but now weight loss is not a factor it comes off for no reason.I am 173lbs 5ft8 before married and baby life I was 125 5ft 10,yep loss even footage! My busy life lead me to your site trying to find meals ideas that will benefit my life and I am so happy to find your meal plan that will be perfect for me to give a try! Sry for the long comment,but I will give your plan a try and keep you updated on the outcome that I am so positive about that will benefit me 100%![i][/i][u][/u][c][/c]
Hi,
I have been having weight loss problems for many years. Now that I am 50, it has become harder.
My question: Am I allowed to have a protein (whey) smoothie on the Fat Fast? I work out in the early mornings, so need it for post recovery.
Thanks so much for helping us.
Hi Naomi, I think that it's better to avoid it on a fat fast. It may be better if you only do light exercise when reducing your calorie intake during fat fast.
I've been stalled for a few weeks now and began a FAT Fast yesterday. Today I found this great plan of yours and have printed all of the menus and recipes. The photos look wonderful, such a variety and very colorful. I've done the Egg Fast in the past and am hoping the Fat Fast will be even better due to the variety of foods I can eat. I found the Egg Fast quite boring even though I love eggs.
Thanks and I love your BLOG and your latest cookbook too.
Thank you Pat, I hope you find this diet plan useful!
I gained 2.5 pounds on my first day following your meal plan?
Ant thoughts? On day two and nervous.
I think it's just natural weight fluctuation (very common for women but also men). Make sure that you first get keto-adapted before following a fat fast. I'd give it 2-3 more days.
what a wonderful blog! i like the photos 😊
i "suddenly" gained 17 lbs over the last year and i need to get back in shape. i think a 5 day fat fast will be just the thing to kick start my keto diet! thk you!
Hello, Have been trying IF for a while and all is good so far.
My work schedule is so tight and I'd like to know if I am doing right.
Get up around 4:30 and be at home 6 weekdays. Try to eat with my boys dinner around 6:30-7:00. And I go to bed around 9. Is it too early? I mean almost 1 hour after dinner I go to bed.
And also, I feel hunger in the morning, because almost 8 hours after rising I only can eat. Should I switch my meal schedules? Or what can I eat/drink if I feel very hungry? I drunk bone broth today. Does it break my fasting?
I really enjoy your website and will try some recipes over the weekend.
Thanks so much, Hanife
Hi Hanife, here's a post that may help (intermittent fasting): Complete Guide to Intermittent Fasting
I understand this may be difficult due to your work schedule but if you feel hungry/dizzy, you should eat more or increase your portion sizes. How about having a quick snack if you can't have a regular meal? Make sure you eat enough protein - that's what will keep hunger at bay. Bone broth is low in calories and I don't think it will break your fast. I hope this helps!
Hi your site is absolutely wonderful with clear pics of your meals and alot of information. It is easy to read and perfect to use,giving one an excellent guide to follow on the ketogenic diet.I am still in ketosis,and have done a test to confirm this,have lost 4 kg over a month,but now over one week i am not loosing at all,scale shows i have picked up 500g.I am really not cheating in any type of way,but have kept strickly to my eating pattern as before.How can a whole week go by without me loosing something.I only eat 2 meals a day which is fine for me.I donot really excercise,and have still lost before and even eat 2 meals a day,wheras others eat 3 meals a day.I have lost steadily,now all of a sudden the scale shows the same as a week ago.But yet i am still in ketosis,so how can i NOT loose some weight in a week.If the body is keeping water,HOW LONG will this go on for? I drink enough water daily too.Am i still loosing weight,although it does not show on the scale?
Thank you Tania, I hope this post helps: How To Low Carb: 15+ Common Weight Loss Mistakes
How does MCT oil fit into this fat fast?
I use MCT oil as a supplement (in smoothies and coffee). You can use it on a fat fast too - just make sure you don't exceed the recommended amounts. MCT oil may sometimes cause stomach distress.
Thanks for this! I've been on keto for 4 weeks now, in ketosis for almost the same period. Apart from a couple of pounds of water weight loss right in the beginning, I haven't lost any weight OR inches although I've noticed that my keto sticks have started to turn a much darker shade of purple in the last 2-3 days...on the other hand, I definitely feel heavier on my abdomen and cheeks.
I'm 5'3 at 110 lbs trying to get to my usual weight of 105. I know that might seem low but I have pockets of (new) fat that I'm trying to lose, e.g upper arms. I restrict my calories to about 1200 on average per week, but calorie cycle to avoid any metabolism slowdown. I'm also sedentary with no exercise at all. My macros are pretty spot-on, ❤️0 g grabs, protein in 50g-65g range and the rest from fats. Fat intake comes from meat, eggs, avocado, oils and occasionally almond butter.
My question is, given that I seem to be stuck on a weight plateau (with slight weight gain) on keto, will the fat fast aggravate the weight gain or help me kickstart weight loss?
Apologies for the loooong email, it helps to confide!!!
Hi Yasmin, I'd actually try something else instead - how about adding some exercise and convert those extra few pounds into muscles? Instead of just losing body fat, I'd try to gain muscles muscles at the same time - if I were you - so you might want to try resistance training and focus on large muscle groups. Have you checked your macros? Here is a tool that will help: ketodietapp.com/Blog/page/KetoDiet-Buddy. I think that 1200 kcal is way too low but it's good that you cycle.
I love this post, but with regards to the woman weighing 110 and 5'3", you should be more vigilant, don't you think? Yasmin is at a normal weight for her height and I think pointing her to information that shows that would be a smart choice. Many women and men looking up fat loss info or diets are at risk for eating disorders...I know it's not your job persay, but it could be a part of your mission.
Thank you Rubie. I did point that out and emphasised the importance of muscle gain over weight loss, but as I explained here, I can only point people to the right direction: Low-Carb Experts
Hi Martina, I have been a LCHF for more than a year and have been in my plateau of 72kg for about 6 months. so i decided to do the fat fast, i am on my 3rd day and i have kept my cal under1200 and high fat about 80% but I have not lost any weight as yet.. still 71.7kg-72.5kg. whats going on?
Hi Anita, fat fasting might help but there is no guarantee that it will always work. What's your "usual" calorie intake like? Have you been eating enough on a regular low-carb/ keto diet? Here is a post that might help: Not Losing Weight on a Low-Carb Ketogenic Diet? Don’t Give Up and Read Further
Hi Martina, thank you so much for this article and for all those tips. I really really like your website and come here often. Do you think that there is any value in fat-fasting once a week, e.g. having a very high fat day (~90%) every Monday or would it be rather pointless? Thanks a lot and Best Wishes. Marie
Thank you Marie! I'd rather go for a day of complete fasting or for intermittent fasting. I'd only use fat fasting for the reasons listed in this post: Complete Guide to Fat Fast Hope this helps!