Copyright 2012-2016 - KetoDiet Blog (http://KetoDietApp.com/Blog)

Complete Guide to Intermittent Fasting

|Complete Guide to Intermittent Fasting

Before I gave up grains, sugar and other foods which I used to believe were healthy (or at least not harmful), I had breakfast every single day. At least that's what all kinds of TV ads were claiming, promoting whole grains and cereals and other "healthy" breakfast options often loaded with sugar. Just the thought of skipping a meal made me feel guilty. Doing a full day fast seemed unnecessary and impossible to follow. But all this has just been part of the big high-carb, low-fat campaign.

Myth #1: Breakfast is the most important meal of the day.

As you will learn in this post, nothing can be further from the truth. I rarely eat breakfast - that's the meal I skip almost every day.

Myth #2: You have to eat regularly, ideally 5 small meals a day.

Once you get keto-adapted and not depended on glucose, this will change. Since your insulin levels will not spike, you won't have the need to eat regularly or in small portions (apart from diabetics which I discuss later in this post).

Myth #3: You need to eat most of your carbs for breakfast because that's when your body uses them most effectively.

You should try to eat your carbs throughout the day and not just in one meal. Furthermore, since our body is in fat-burning state in the morning, eating carbs in the second half of the day is more beneficial for weight loss.

Myth #4: Never exercise on an empty stomach. It's bad for your performance and you'll lose muscles instead of body fat.

As described below, for most people Intermittent Fasting is ideal for maximising the benefits of exercise for several reasons.

What is Intermittent Fasting (IF)?

Compared to calorie restriction, IF is not restricted in calories - it simply limits your eating windows to just a few hours a day. In effect, you usually fast for 14-20 hours or even up to 36 hours.

The idea is that you should be eating ad libitum (as much as you want) during your "feeding" window, but you should not eat or drink anything with caloric value during your fasting window (black coffee or tea sweetened with stevia or Erythritol are allowed). You should be aiming at reaching your daily macronutrient targets and without restricting yourself - simply eat to satiety.

If eating ad libitum means that you may not meet your macronutrient targets, that's just fine. Your appetite is what will determine how much you should eat. Aim for your daily protein intake and use fat as a "filler" to sate your appetite while keeping carbs low (20-30 g net carbs). Remember, if you eat less protein than required over a long period of time (not just a day or two), you may lose muscles, decrease your basal metabolic rate and therefore burn less body fat. That's why losing muscle mass is what you really want to avoid.

If you need to know how to find your optimal food intake, try KetoDiet Buddy - our online keto calculator.

Just like Fat Fasting (guide is here), Intermittent fasting (IF) is a diet approach that is often used for breaking though a stubborn month-lasting weight loss plateau. Although Intermittent Fasting is not always a guarantee for weight loss, it has proven to have several health benefits.

IF versus Calorie Restriction

Most studies compare Intermittent Fasting to calorie restriction in the sense that both have several health benefits. However, unlike IF, calorie restriction has many downsides: it's difficult to stick with and can be frustrating. It leads to muscle loss, loss of bone mineral density and may also cause severe micronutrient deficiencies. This is, of course, relative and depends on the scale of the calorie restriction. Another study of mice compared IF and calorie restriction and found that IF exceeded the beneficial effects of calorie restriction. This study compared individuals on IF and calorie restriction and found both to be equally effective for weight loss, although IF was better for the retention of lean mass. So, what if there was a way to improve your healthy and enjoy life without restricting yourself at the same time? It seems that Intermittent Fasting is the best way to achieve both.

Bottom line: Fasting seems to have all the benefits of calorie restriction without its downsides. Fasting leads to natural calorie restriction - without forcing yourself, you will likely eat less. Even if you have a large meal after a fasting period, it will likely not make up for the time you have been fasting.

Sign up for FREE and get:

  • 3 free diet plans to help you kickstart your diet, lose weight and get healthy
  • Recipes, giveaways and exclusive deals delivered directly to your inbox
  • A chance to win the KetoDiet app every week

Get this for FREE

How Does it Work? Types of IF

When we are fasting on a low-carb diet, our body is using fat stores for energy and we lose body fat. Fasting on a ketogenic diet has more benefits: since our body is depleted from glycogen, we use fat and ketones for energy instead of glucose.

Healthy low-carb eating is great for appetite control and keeps us fuller for longer. As your body gets used to fat and ketones as main sources of energy, you will naturally eat less amount and less frequently. That's the best time to try Intermittent Fasting.

There are several types of IF:

1) Skip a meal every now and then. It is important to note, that you must not force yourself and start feeling too hungry. It should be a gradual process, where you slowly get your body used to it by putting your next meal off slightly every day until you skip it. It's my favourite way to do IF and what I practice 4-5 times a week by skipping breakfast. I'd usually have Monday to Friday with IF and have weekends off. This is, in fact, what most keto-adapted people do - they eat when they are hungry because foods high in fats, moderate in protein and low in carbs induce strong satiety.

2) Break a 24-hour period into 2 segments / windows (e.g. 18/6). This means you fast for 18 hours just drinking water or tea and have a 6-hour period of calorie intake. You can also have 16/8, 20/4 or even 21/3 periods based on what suits you best.

3) Active individuals, IF combined with exercise. It's an approach similar to the one above but also includes exercise. Martin Berkhan, the author of LeanGains has further described this approach suitable for active people in this guide. Apart from working out in the fasted state (with only 10 grams of BCAA), there are more rules to follow. Your post-workout meal should be the largest one and you should pay attention to the macronutrients on your active vs resting days. Your ideal macronutrients then depend on your goals (fat loss, muscle gain or body recompositioning). In general, on days of your workouts, you should be eating more carbs while on your rest days you should focus on eating fat. Protein intake should be kept high on all days and depends on individual needs. You should also try to keep your feeding window constant as it will help you stick with the plan.

4) Alternate days of fasting with days of unrestricted eating while still eating low-carb food. This approach may be too extreme for most people and I wouldn't recommend you follow it unless you've tried one of the above methods first. You can do this by including one or two fasting days a week.

5) Combination of Fat Fasting with Intermittent Fasting - instead of eating 5 small meals on a traditional Fat Fast, you can try 1-2 regular high-fat meals which makes it easier to follow. I've further described this approach here.

Bottom line: Whether you decide to include one fasting day a week or skip breakfast every day like I mostly do - do what works best for you. Just make sure you don't end up eating too little - you should meet your macros on most days - IF is not about starving!

What Are the Benefits of Intermittent Fasting?

Occasional fasting has been proven to have the same benefits as calorie restriction. Most studies on Intermittent Fasting to date have been focused on its health benefits.

IF improves metabolic syndrome markers

Studies show that IF improves blood lipids, cardiovascular markers, improves insulin resistance & increases insulin sensitivity, reduces blood pressure and inflammation markers (Study 1, Study 2, Study 3).

Longevity

Several studies that were performed on mice showed increased lifespan when a period of fasting was included in their diet. Most likely reason for that is that fasting affects the ageing process via calorie restriction. Another reason for increased longevity can be the fact that fasting improves the symptoms of metabolic syndrome (obesity, diabetes, etc.) and reduces the risk of cancer. Also, fasting and ketosis has proven to enhance autophagy (body's ability to "repair" itself). Autophagy is required for muscle mass maintenance and has anti-ageing properties. Finally, fasting has shown to enhance production of growth hormone which is known to naturally decrease as we are ageing.

Cancer

This review of studies shows that metabolic factors are strongly linked to various types of cancer. The strongest risk factors identified in men were high levels of blood pressure and triglycerides, and in women with high plasma glucose. Since IF improves metabolic syndrome markers, it also reduces the risk of cancer. Additionally, this study shows that fasting helps reduce the negative side effects of chemotherapy in cancer patients.

Mental clarity and neurological health

Fasting and ketosis are good for the brain. Once your body becomes keto-adapted and you are no longer glucose-dependent, usually in 3-4 weeks, your body will effectively use ketones, dietary fats and stored body fat for energy. No brain fog and more focus - you can learn more about how ketosis can enhance mental clarity in this post by Dr Bill Lagakos. Intermittent fasting can improve neurodegenerative diseases such as Alzheimer's, Parkinson's, Huntington’s disease and stroke. Scientists at the National Institute on Aging, led by Dr Mark Mattson found that in animal studies Intermittent Fasting can increase the resistance of neurons in the brain to dysfunction and degeneration.

Improved fitness

When you exercise in the fasted state, you'll enhance fat burn. Since you have low glycogen stores, your body will use ketones and body fat for energy instead of glycogen. Contrary to common beliefs, fasting does not have a negative effect on performance. Studies show that it can either improve performance or have no effect (Study 1, Study 2). Will you lose muscles if you train in the fasted state? No, you won't - fasting also enhances muscle protein synthesis and recovery after exercise (Study 1, Study 2).

Weight loss

Intermittent fasting is not about starving. When you follow IF, you effectively eat the same amount of food as you would on your non-fasting day, just in a shorter eating window. This by itself usually doesn't help weight loss. The main reason people lose weight on IF seems to be the fact that they naturally eat less. Imagine, if you are already keto-adapted and have just one or two large meals, you will unlikely eat the same amount of food as if you were to have 3 regular meals.

Also, studies show that Intermittent Fasting increases fat oxidation. As mentioned above, it increases the production of growth hormone and decreases insulin levels: all these are factors that help us to lose body fat. Compared to calorie restriction, most studies on IF show that people find IF to be less restrictive, easier to follow and they better adhere to it.

My personal experience: I do IF by skipping meals and found that on days of IF, I naturally eat 20-30% less which I confirmed by using the KetoDiet app. Below is my progress chart where the spikes close to 2000 kcal are either the days I exercise or days without IF (usually weekends) or a combination of both.

What is more effective for weight loss? Calorie restriction or Intermittent Fasting? This review of studies compared the effects of calorie restriction and IF: "these diets are equally as effective in decreasing body weight and fat mass, although intermittent fasting may be more effective for the retention of lean mass." As you know, retention of lean mass is important for long-term weight loss as it plays role in our basal metabolic rate. The more lean mass we have, the more calories we burn at rest.

Convenience:

Being used to IF is great for those who can't always find low-carb foods - either they are travelling, at work with limited options or too busy to cook. Although I would suggest you take low-carb snacks or prepare your meals in advance, this is not always possible. Also, with less meals to prepare, you will save time and money.

Bottom line: Indisputably, there are several benefits of IF. However, the truth remains that there has not yet been a long-term, randomised clinical trial of IF in humans to tell whether or not it extends our life or leads to a sustained weight loss. These potential benefits have only been assessed based on short-term studies and studies in animals.

7 Tips on Getting Started

1) Don't try IF during the first few weeks of a low-carb / ketogenic diet OR if you follow SAD (Standard American Diet). This is very important, as your body has to first get keto-adapted prior to trying IF. You will first need to get used to low-carb eating so that your body can be fully utilising ketones for energy instead of glucose. If you try IF straight away, you won't succeed, as you will initially be glucose-dependent and too hungry to follow it. There is a lot of misinformation on the Internet about IF. Intermittent fasting should be natural and you should not struggle and feel hungry. It's a gradual process and will take time before it can be used effectively. You can learn more about the basics and how to start following a ketogenic diet here: Guide to Keto & Paleo

2) Don't plan IF - listen to your body. IF works best when it's done naturally. It it time for lunch and you don't feel hungry? Skip it and keep the food for dinner. Is it too late to eat? Skip dinner and have a large breakfast instead. I mostly do IF from Monday to Friday by skipping breakfast and sometimes even lunch. In most cases, I would just have my first meal at 1-3 pm and I try to eat at least 3-4 hours before bed to have enough time for my body to digest and avoid sleep disruptions. I don't usually do IF on weekends because I may be going out or simply enjoy having breakfast with others purely from its social point of view :-)

3) Don't force yourself into IF, start slow. As mentioned above, IF should be natural and you should not restrict and deprive yourself. Once you become fat-adapted, you will feel less hungry. Start by avoiding snacking between meals. Then, try skipping "regular" meals but only if you don't feel hungry.

4) Keep yourself busy. I find it easier and more natural to skip meals when I have a busy schedule and don't spend my time near the kitchen. Even if you don't feel hungry, you may be tempted to have a treat or a snack if you are surrounded by food. Based on my experience, I can easily be without food all day when I'm out shopping or meeting people. I may have a coffee, tea or sparkling water but that's about it.

5) Don't expect that IF will fix everything. Although IF can potentially help you lose weight and live a longer life, it's just one of the several factors that will help you meet your targets. Stress levels, sufficient sleep, macronutrients & micronutrients and exercise are just some of the most important factors to consider. Don't use IF as a "quick fix" when you eat more carbs than you planned for, at least not too often. You should do it naturally and should never feel deprived by doing IF.

6) "Bulletproof / butter coffee" will break your fasting period. Ingesting of butter and coconut oil / MCT oil won't maintain your fasted state. Anything with a caloric value will have the same effect and that's why it's called "fasting". What you can do is have a regular BPC or my Ultimate Keto Coffee for breakfast, skip lunch and only have dinner :-)

7) Be warned that IF is not for everybody. According to Dr John Briffa, the author of Escape the Diet Trap, people suffering from anorexia nervosa, bulimia nervosa and Type 1 diabetes should avoid it completely.

Type 2 diabetics should only do it under medical supervision (so they should when following a low-carb diet), because they may need an adjustment to their medication. Others who should avoid IF are those who are generally "stressed" or suffer from chronic fatigue and adrenal disorders, those with lack of sleep or those who overexercise.

Also, studies suggest that pregnant and breastfeeding women should avoid IF. Mark Sisson has a great post in which he explains why IF may not be an effective weight loss tool for pre-menopausal women or even women in general.

No diet plan lots all and you'll have to try how IF works for you. If you experience side effects like sleeplessness, anxiety, irregular periods, or hormone imbalance, you should avoid IF.

Intermittent Fasting: What to Eat

I've been working on easy-to-follow sample meal plans for specific types of IF (skipping lunch, breakfast or dinner, "one meal a day" IF plan and even more). For now, you can check out the recipes on my blog, especially recipes in these categories: Main Dishes and Breakfast - Stay tuned!

Now I'd like to hear from you. What is your experience with IF? Has it helped you lose weight / improve health / feel better?

Sign up for FREE and get:

  • 3 free diet plans to help you kickstart your diet, lose weight and get healthy
  • Recipes, giveaways and exclusive deals delivered directly to your inbox
  • A chance to win the KetoDiet app every week

Get this for FREE

Add comment

biuquote
  • Comment
  • Preview
Loading

Please, note that I do not offer personalised advice. For personalised advice you can contact one of our experts.

Comments (78)

Thank you for your Blog.  I wondered if anyone else has had a craving during the day for the BPC, I seem to crave it and of course takes my appetite away. Also I stopped using butter, cream or half and half, as the dairy was too much for me.and I limit the intake of cheese.
I'm definitely going to try IF, I have lost 11 pounds in 4 months, not much by others.  My activity is low, so I know I need to change this.
Any suggestions for me?

Reply

Hi Stacy, if you crave BPC, don't avoid it. If you want to try IF, you should not force yourself to fast and instead only eat when you are hungry. I don't think that including BPC classifies as fasting but I do think that there are still great benefits because it will provide an energy boost from fats that are better digested.
I don't think you need to exercise to lose weight but it does help if you include some exercise for other reasons: ketodietapp.com/.../how-to-exercise-on-a-keto-diet
Here's how to calculate your macros on a ketogenic diet: https://ketodietapp.com/Blog/page/KetoDiet-Buddy

Reply

Hi. I use Pure Planet Best of Greens whole food supplement. It's a green powder that gets mixed with water. There is no caloric information on the bottle & I contacted the company that makes it & tthey can't provide me with caloric information. Do you think taking this in my fasting window would break my fast?

Reply

I think that unless there is added sugar (and I don't think there is), a serving shouldn't have a significant caloric value. I think it's probably fine for fasting.

Reply

Why should pre-menopausal women avoid IF??

Reply

Hi CynD, recent studies show that IF may not an effective weight loss tool for most pre-menopausal and peri-menopausal women. On the other hand... what works for some may not fork for others - you can give it a try and see how it works for you.

Reply

I found the following info towards HIIT and Keto. If you want to find the source, just google a bit of the paragraph.
The body burns primarily glycogen when the heart rate is above 70% of its max. Therefore, aerobic exercises such as HIIT are good for burning liver-glycogen stores during induction, but such high-intensity exercise is not recommended once under ketosis as once muscle-glycogen stores are depleted, the body will begin catabolizing mainly muscle-mass under any high-intensity activity.
The ideal aerobic exercises to perform when under ketosis are MISS (medium intensity steady state) and LISS (low intensity steady state).

Reply

I don't think this is accurate - studies show the opposite for HIIT and keto. You can do HIIT, which is anaerobic, on keto and you won't lose muscles because you will use body fat and ketones for energy (unless you are severely underweight and have very low body fat - Volek & Phinney). HIIT is muscle-sparing, LISS can actually cause muscle loss.
Here's more about HIIT: ketodietapp.com/.../how-to-exercise-on-a-keto-diet
ketodietapp.com/.../keto-diet-nutrition-and-exercise-carbs

Reply

Very good blog and I thank you. This is more of a success story then a question...
I am 55. I started a lchf diet about 3 months ago. I lost 20 pounds in 2 months. I have since then hit a plateau. I only have another 10 to lose.
So I started IF last week. I work out 3 times a week doing HIIT. I work out in the morning. Monday, Wednesday and Friday. On those days I skip breakfast. I have BPC and then I hit the gym.
I guess I am worried about getting hungry.... My BPC breakfast concists of 2 cups of coffee with butter and a "side order" teaspoon of coconut oil.
Now I was surpprised to read your comments on BPC and IT. I will definitely try cutting out the BPC breakfast and see how that goes.
By the way, I have not felt this good in over 15 years...

Reply

Well done Miko - I hope it helps! You may want to read this post too: ketodietapp.com/.../how-to-low-carb-15-common-weight-loss-mistakes

Reply

I want to make my keto diet plan... can you help me or suggestions me.. my body body weight is 86kg ... and I am non vegetarian and doing regularly workout.. pls tell me diet

Reply

You can try one of my free diet plans here: http://ketodietebooks.com/

Reply

I read elsewhere that Bulletproof coffee (with butter & coconut/MCT oil) will NOT break a fast despite the high calories. This is because it is pure fat and does not raise your insulin levels.
I think Dr.Sara Solomon also mentioned that in one of her FAQ videos.
But she cautions that one must not forget to take those calories into account when tallying up total calories for the day.
You say the exact opposite about bulletproof coffee and now I'm confused Frown

Reply

I'm not against BPC - I do have a cup every now and then. However, I don't use it during intermittent fasting (as part of the "fasting window") - I just count it as a "meal/snack".
I understand that there are arguments for and against BPC on IF - this is where opinions vary. As long as it works for you and you see added benefits, there is no reason to change your approach Smile
In general, here are my thoughts on BPC...
- It should keep you fuller for longer. This is beneficial unless you significantly reduce your food intake (which may result in micronutrient deficiencies if it's more than just a few days). You should experience mental clarity and increased energy levels.
- It may not be working as expected and you may end up eating more calories (regular meals as before + added fats from BPC without reducing food intake).

Reply

yea....as far as breakfast goes, highly overrated (I speak for myself). I can "cleaned out" much better when fasting and skipping breakfast. Is it hard? That depends. When I started IF and ate "more carbs" it was hard. I went zero carb/low-carb and the second time around with IF it was easier. Carb crashes made IF harder for me to do it. Eating just meat and fat it becomes easier and less cravings.

Reply

Hello!
I started the LCHF life a little over a year ago. Overall I have lost 30 lbs, but that is it, and I still have another 30 lbs to get to an "average" weight.
I was successful at first and have been able to keep the weight off and not gain any back. I have slacked quite a bit since November, and have attributed my slacking to the fact that I have not been losing lbs.
About two months ago I decided to get serious again, but have had minimal results,I am only down 5 lbs. I did read your "Mistakes on Keto" blog, and I do know that I do cheat from time to time with a bite here or a bite there, and once or twice I did have a full cheat day.
But for the most part I am good. I usually only have coffee with heavy cream and sweetener for breakfast, lunch whenever I am hungry that includes a salad and whatever entree I cooked the night before (usually protein in butter, and veggies in butter or olive oil) and then dinner.
I have not followed your Macro guide and do not count carbs much. I just eat low carb veggies everyday, protein, and low carb berries on occasion.
After reading through your blog, I wonder what I should try to do to get out of this slump and back on track. Should I follow your Macro guide and pay more attention to reaching the goals through your calculator, or should I try the Fat Fast or Intermittent Fasting? What do you think I should try first? My only issue is that I know it is ideal to follow the Macro guide, it is very difficult to count those Macros for every meal. I know you recipes include the counts, but I do not use just your recipes, I use others or my own.
Thank you for your blob! and Thank you for your help!!

Reply

hi Erica, I think you might want to consider counting macros just to get an idea where you are and whether there is something you might have not realised. If you have an iPad, you can download our tracking app (iPhone and Android coming soon). I'd start with counting macros and then IF but only if you feel comfortable with skipping meals. You should not feel hungry.

Reply

I enjoy an orange and lime slice in my water. Would that break IF, and should I be counting that as carbs? Thank you for all of the useful information, I have really loved this group!!

Reply

Hi Marci, no, that would not break your IF because it is only used to add a bit of flavour and has less than 50 calories.

Reply

Can you expand a little bit on the topic of butter/coconut oil coffee? I've been IFing for a couple months now, some times I'll do a teaspoon off coconut oil in my morning coffee. I've read on other sites that this is fine because it will not cause a spike in insulin, and will boost ketones. Can you expand on your comment please?

Reply

Hi Zack, I mentioned some of the issues with butter coffee in this post: ketodietapp.com/.../how-to-low-carb-15-common-weight-loss-mistakes I personally don't use BPC for IF (I count it as a full meal) but I do make it every now and then for breakfast because I like it.

Reply

Hi Martina,
I just wanted to add that I was recently diagnosed with mild type 2 diabetes, and was prescribed medication: 500mg of metformin twice a day.  However, I decided not to go on the medication prescribed, choosing use a low-carb diet with 16/8 IF instead.  Two months later, I'd lost 30 pounds, my blood sugar was back down to normal (5.2mmol/L).  I informed my doctor of what I'd been doing, and he agreed that I should continue.  
Of course, I'm not a medical professional, and I realize that everyone reacts differently.  However, I wanted to contribute my personal experience with IF, which has been very positive.  Thank you for continuing to encourage people to take charge of their health!

Reply

Thank you for sharing this with us, Ben, and well done!!

Reply

Hi Martina,
I have  question regarding IF and working out in the morning. I have found that my body doesn't get hungry until about 12pm and I only want a little something, but I want to know if using an amino acid drink 10 calories within one hour after my workout but before my eating window will negate IF?  I have read that supplying the body with amino acids after a workout is helpful in saving your lean mass? Any comment/help.
Thanks.

Reply

Hi Michelle, such a supplement will not break your fasting window because it's less than 50 calories.

Reply

Great read and very informative. Cheers

Reply

8 weeks ago, I jumped straight into IF following the lchf diet. Before that, I followed a  calorie restricted, low fat diet, with few results. After a lifetime of brainwashing, I'm struggling to maintain higher fat levels, but I'm working on it. I do the BP butter coffee in the morning with 10g of organic whey protein, and other than that, don't eat between dinner at 7ish the previous evening, and lunch between 1 and 2pm the following day. In the first two weeks, any carbs over about 50g and my dipstick (medical grade urine analysis) would be clear of ketones. Since then, it has been difficult to lower the ketone readings on the dipstick. I've eaten an entire white bagel for lunch with no lowering effect. Though eating gluten again was a killer - I had immediate IBS symptoms. Yesterday, being Easter, I thought I'd treat myself to a heap of sugar (all in the name of science) and ate a load of milk chocolate, wheat flour pancakes, bagel ... you name it! I was sure my dipstick test this morning would show no ketones at all. I was wrong. Even with the big glucose and resulting insulin dump, there were still levels of ketone on the stick.
Am I ever hungry doing the BP style IF? Not ever. I cannot eat to hunger as I am never hungry, and would only consume the butter coffee. I have to force myself to eat to avoid starvation ketosis. Do I exercise? Not at all and I haven't done in the previous year due to serious injury (though this time it's just part of my experiment, and I plan to soon). Have I lost any weight? 14lbs in the first 5 weeks, and then I stopped measuring. Have I lost any inches? And here's the biggy ... I was so inflamed and bloated before I looked 9 months pregnant! Now my waistline is reduced by a whopping 5 1/2 inches, and my other dimensions are just as dramatically reduced.
My instinct about why this is ... firstly, I have a lot of weight to lose, so moving this body at all uses much more energy. Gettinng rid of inflammation in the body allows other processes to work the way they should. Not having that carb brain fog and loads more energy makes you want to move more. That's just my opinion though. Looking forward to getting back on the wagon after Easter because I can't stand feeling like a carb zombie for another minute. Experiment over!

Reply

Hi Jacquie, I'd avoid BPC in your case. If you don't feel hungry and can't get enough calories, using BPC would only result in nutrient deficiencies. Urine ketone strips are not reliable and chances are that you measure ketones because you are not eating enough, even when you have more carbs. Good luck and keto on!

Reply

martina i am having problems with 29-30 carbs.  i am a bodybuilder so when i plan meals, i can get values for fats really spot on near maintenance.  proteins i lack maybe 20-30 g sometimes.  but carbs i tend to go over by 10 -15 g and it is frustrating me.  what can i do.

Reply

Hi Mark, it's hard to tell why you go over your carb intake. Do you count "net" or "total" carbs? It's not necessary to count "total" and follow a very low-carb diet. Up to 50 g total (25-30 g net) is fine for what you want to achieve: ketodietapp.com/.../Total-Carbs-or-Net-Carbs-What-Really-Counts
Here is a keto food list: ketodietapp.com/.../Keto-Diet-Food-List-What-to-Eat-and-Avoid
And here are sample diet plans: http://ketodietebooks.com/

Reply

Hey Martina quick question. I am a 35 year old male and have been doing keto fasting for a month. Ive been working out at 5 am and not eating till 11-12.... Seems like my weightloss has been minimal. 20-30 carbs a day on about 1800-1900 calories. Some days I run up to 3 miles. Do you think my calories are sufficient? I feel so full all the time. Thanks for your help

Reply

Hi John, you seem to have a very busy lifestyle - I would personally find it difficult to work out at 5 am. Do you sleep enough? Sleep and stress levels are huge factors in weight loss. When and how much you eat should be mainly determined by your appetite (apart from daily macros). I don't always have a post-workout meal either. To find out if your macronutrients are sufficient, please, check out our keto calculator: http://ketodietapp.com/Blog/page/KetoDiet-Buddy

Reply

Hi Martina, Very informative post, thank you!
I was on vacation for 2 weeks and decided to try IF for that period and was eating from 1pm-7pm and really found it easy & felt great. I did however drink my coffee in the morning with a bit of cream (about 25 cals worth), but I still seemed to do ok.
Now this week I'm back to work where my work day starts at 6am and is 12 hours long and I'm finding it very difficult to maintain my fast through the morning and am back to eating the way I was prior to IF and I'm gaining weight!
Would it be acceptable to eat breakfast & lunch & skip dinner? I think if I could get my eating in while I'm at work, around others who are eating, I would find it easier. Its difficult to sit here, not eating breakfast when everyone is eating bacon around me! I may have to extend my eating window  to a 8/16 or even 10/14 on work days and then back to 6/18 on days off.
I do think IF is the right choice for me because I have issues with binge eating in the evenings and that is completely controlled by IF. I also find I sleep better which is an added benefit. Thanks for all your great info! Krista

Reply

Hi Krista, yes, you can switch / postpone your "eating/ fasting window" until you feel comfortable. You should eat when you're hungry - yes, you can definitely skip your dinner instead. You can start with 10/14 window and see how you feel. Low-carb eating should naturally lead to a reduced appetite and you shouldn't feel hungry. If you do, eat more often or larger portions. I wish you all the best!

Reply

What works best for me is to consume nothing but coffee/tea with capryllic MCTs throughout the day, and then start feeding any time after 5pm.
I find that adhering to this regimen significantly increases my energy levels, confidence, mood, work ethic, workout performance, sex drive, etc. Probably because intermittent fasting has been shown increases testosterone by 80% or something like that.
You just have to manage your sleep, since it seems to amplify keto-related sleep difficulties. Definitely helps to have a sizeable amount of dark chocolate before bed, particularly if you had very few carbs during your feeding window.

Reply

That's great Derek! Sleep is a huge factor in weight loss, energy, hormone levels and overall well-being.

Reply

Great post, I commend you on mentioning that it is not for everybody, as someone who suffers with ME/CFS I would love to try it but feel it would be too much for my body to handle.

Reply

Thank you Marcin, yes, IF with chronic fatigue syndrome is problematic. I have Hashimoto's, which is not the same but similar, and I avoid large eating/fasting windows. I have no issues when skipping a single meal every now and then.

Reply

Hi! Why is it not safe to do IF when you are first starting ketogenic diet?. Today is my 3rd day on low carb and high fat and also fasting 18/6. I feel great! I'm not sure if I'm in ketosis already, but I don't have any issues with fasting, not hungry or anything. What do you suggest?.

Reply

Hi Suzy, it's safe but it's not recommended. It's better to do IF when your body gets keto-adapted and is not depended on carbohydrates. You will feel less hungry and it will be easier for you to do IF. So if you can do it and it feels natural without hunger issues, go for it Smile

Reply

Hello Martina!! Cheers from Greece!! Love your blog, it is really useful!!! Although, I have a problem understanding how you manage to IF while taking the necessary proteins.
I do not feel hungry all day and I force myself to eat breakfast and lunch, because I want to take proteins (i have to eat 1400 cal/day and 50 proteins according to keto buddy - I do not work at the moment).
I suppose it is a matter of habit (if I say it right - don't speak English fluently). I am in keto diet for 1 week and a half now.

Reply

Thank you Gianna! When IF, you get most of your daily macros in just one or two meals but even if you don't, it doesn't matter, unless you are doing it every day and not getting enough protein in the long term. I do IF by skipping a meal, usually breakfast.

Reply

Hello, I just start yesterday a new protocol that is.
Alternate day where, in train day in the morning i eat 250gr proteins-140gr fat - 30gr carbo around 2300kcal. Day after i fast till 1pm i do cardio training on these days than i break my fast with 220gr pro-80gr fat-30 gr carbo. Saturday dinner cheat and carbs meal. I am a bodybuilder

Reply

Hi Gino, have a look at this tool: http://ketodietapp.com/Blog/page/KetoDiet-Buddy

Reply

Hello, you say that any kind of caloric intake during your fasting periods disrupts the fasted state.  What about medication? Could taking my morning meds  disrupt my fasted state?

Reply

Hi Anna, I think that the limit is about 50 calories so you should be ok. However, I don't know what medication you're taking but make sure it doesn't upset your stomach if you eat nothing with it.

Reply

So I've been reading your site a lot today. I haven't followed ANY diet sites/plans/whatever before, just eating "whatever I want". I used to eat a lot of fast food for lunch, but I was getting quite uncomfortable digestive distress after eating. So I basically stopped eating lunch (I've not eaten breakfast in years, besides the odd Saturday). I guess I've pretty much been doing IF for the past couple of months (though I'd never heard of it).
Now, the potentially strange part: my "meal" at dinner (only meal of most weekdays besides the odd snack) was/is cold cereal with milk. Obviously this is very high in carbs. I estimate I can eat >1,500 calories of it in one sitting, with the obvious (bad?) balance of high carbs, medium protein, low fat. Anyway, the thing that seems weird to me is that I don't usually even think about being hungry at lunch (anymore), or even anytime during the day until about 4-5pm.
I'm wanting to see if I can maybe switch my evening meal to something HFLC, but it's hard for me to want to prepare anything (no preparation with cereal). Plus I really love a good bowl of cold cereal (though I love meat too).

Reply

I think that a bowl of cereal is not only high in carbs but also sugar (unless you use sugar-free) and low in protein. What this means is that most likely you are not getting enough protein for the day.
Even if you don't feel hungry, this may cause you to lose muscle mass. I think that you can try switching to snacks like avocado or macadamia nuts or maybe even toasted coconut flakes - you will like these if you like cereals: ketodietapp.com/.../Spiced-Coconut-Chips-for-the-Fat-Fast)
or this recipe - porridge/ oatmeal (ketodietapp.com/.../quick-keto-oatmeal)
or even this recipe - granola (ketodietapp.com/.../Pumpkin-Spiced-Granola). Also, I suggest you check your macros here to see if you are below your protein requirements: http://ketodietapp.com/Blog/page/KetoDiet-Buddy. Hope this helps!

Reply

Also, i know there's a difference between being in ketosis and being keto-adapted, right? But how does one know if they're fully and highly keto adapted?? Is it a consistent ketone level as well as a fasting glucose level?? I heard around 1.0 blood ketone level and around 80 fasted glucose in the morning/fasted? Is that correct and how else does one know they're highly adapted??

Reply

Yes, you can be ketosis just after a few days of a ketogenic diet. However, to become keto-adapted, your body will need at least 3-4 weeks. Being keto-adapted means that your body can use ketones and fat effectively for energy and is not depended on glucose. You can learn more about this here: ketodietapp.com/.../Ketosis-Measuring-Ketones

Reply

What about skipping dinner and working out in the AM ? Everyone always talks about skipping breakfast, maybe it feels easiest to most but is there any difference or benefits to which meal I skip? Wouldn't it be better to not eat a lot anywhere close to bedtime? And isn't it better to eat after a workout then staying in a fasted state? Thank you so much!

Reply

Hi Nicole, yes, you can do that if you like. I personally prefer skipping breakfast and working out either on an empty stomach in the morning / noon or in the evening. I think it depends what works best for you. I don't like skipping dinner but I don't eat a lot in the evening either (I eat most of my calories round 3-6 pm).

Reply

I've been following IF (breakfast skipping) for a week - i eat lunch around noon and I'm DONE eating dinner by 6-6:30 at the latest, and I am completely stalled. I figured with more "burn" time, i would lose some this week.  I have been on keto for 16 months, lost 179 pounds (with 45 more to go), I'm 5'6" and my macros are around 1250cal, 105+g protein, 90g fat, VERY low carb 3-5g a day.  Any suggestions?

Reply

Hi Wendy, first, congrats on your weight loss!! That's amazing! Less carbs won't always help you lose more weight. I think that 20-30 g net carbs would be better and provide more micronutrients. I suspect you may not be getting enough electrolytes and other nutrients. Have a look at my post here - it explains why you don't need to follow a "zero-carb" diet: ketodietapp.com/.../Total-Carbs-or-Net-Carbs-What-Really-Counts
I think you may also be over on your protein intake but to be absolutely sure, try this tool: http://ketodietapp.com/Blog/page/KetoDiet-Buddy "Slow fat loss" option is usually enough. Hope this helps!

Reply

Hi, so I've been intermittent fasting and fasted weight lifting since an year and eating moderate carbs and protein and low fat.
I've lost 10kg... only.
as most of time I would feel more hungry. But recently after starting to take a tbsp of coconut oil and blending it in coffee for morning in IG, I heard on Dave's blog it doesn't break the fast. You say it does. Does a tbsp of coconut oil blended in coffee break the fast resulting in me not getting the benefits of IF? Frown I've gone keto and I'm adapted on it, been over a month. But my problem is lightheaded and I can't focus.
I eat 104g protein and 83-86g fats and 30-40gm carbs. following the tkd protocol. And I do workout. Can you tell me how to get rid of the brain fog people describe and what about IF and 1tbsp of coconut oil blended in coffee conflict where on Dave's (the bullet proof guy) blog he says no problem.

Reply

Hi Naman, technically, anything that contains calories breaks the fast, even coconut oil. On the other hand, I don't think that's what is causing your brain fog. Some people use BPC instead of breakfast and it seems to be working for inducing satiety & eat less. On the other hand, apart from fat, butter / BPC coffee contains no micronutrients and just fat so make sure your diet is nutritious. Try this tool - you may be running low on fat and maybe also high on protein: http://ketodietapp.com/Blog/page/KetoDiet-Buddy
I think you may not be keto-adapted and that's why you feel that way. You don't need any pre-workout carbs once you get keto-adapted. Instead of TKD (pre-workout carbs), I suggest you try SKD or carb re-feeding (post-workout carbs) depending on on the intensity of your exercise and what your goal is. Carb re-feeds are not usually needed for weight lifting. It can, actually make it more difficult for you to get keto-adapted.
Here is a guide to the keto diet just in case: ketodietapp.com/.../Practical-Guide-to-Keto-Paleo-Diet-for-Health-and-Long-Term-Weight-Loss

Reply

Can you educate me about Keto diet and pregnancy. can I continue with the diet when I am pregnant, maybe for the 1st trimester.

Reply

Yes you can but you should not try to lose weigh, at least not too fast. There is more information about keto & pregnancy in this post: ketodietapp.com/.../Ketogenic-Diet-FAQ-All-You-Need-to-Know (search for "pregnant").

Reply

Hi Martina,
I am on the LCHF diet for more than a year. I have been doing IF for a few months also. I started off with 2 meals per day (16/8). It worked great for me but recently I moved to one meal per day (only dinner) as I am trying to shed some fat I gained over the past few months. My only problem is brain fog. I cannot seem to get rid of it.
Any thoughts?

Reply

Hi Maria, did you have the same issues on the two-meal plan? Brain fog can be caused by excessive protein or carbs too but I doubt you eat too much of either if you have just one meal. Are you tracking your intake - are you eating enough calories? It's quite tricky to get enough in just one meal and you may also be lacking micronutrients.

Reply

I track the macros and every day and my meal is around 1100 calories (around 20 grams of carbs, 50 grams of protein and the rest fat). Micronutrients is what I was thinking as well but I am not sure what it could be. Do you have something specific in mind?
Thank you for the reply and keep up the good work! I always start my day by reading your blog.
I am throwing an idea out there but have you ever thought about opening an LCHF restaurant/bistro? I know that a paleo restaurant opened recently in Notting Hill, London but I have not tried it yet. Sometimes it is difficult to find something to eat outside except for the usual steak and vegetable dish and I wouldn't mind knowing that there is a place I can go that I will not have to worry about what exactly there is in my plate.
Best,
Maria

Reply

Thank you Maria! I really appreciate that Smile
I think 1100 kcal is way too low (more like the "fat fas" intake that only lasts for 3-5 days). Protein also looks too low to me but you'll have to use this calculator to be sure: http://ketodietapp.com/Blog/page/KetoDiet-Buddy (avoid the "fast" or "moderate" fat loss options if the calories are too low). My guess would be that something like 1400-1600 kcal would be better for you.
Yes, I have though about that and even more projects for this year but I've now been working on too many projects and have literally no time. But I'll let you know when or if that happens Smile I have also heard about the paleo restaurant but haven't been there yet. I know what you mean, it would be quite nice to not have to worry about what to order. I often eat at Zizzi, Cafe Rouge (I like their All Day English Breakfast - without the bread), Wildwood, Jamie's and even some Mexican restaurants.

Reply

Just out today--why diabetics should adopt meal timing (i.e., eat more for breakfast, and less for dinner):  www.sciencedaily.com/.../150316122723.htm
If only two meals/day (or less)are eaten, this may work as far as lowering or eliminating Dawn Phenomenon.  If more meals are eaten during the day than that, it may spur "afternoon diabetes" which will lead into high evening numbers and elevated levels of Dawn Phenomenon (I speak from experience with Hubby, a Type 2).
He is now stabilized with two meals/day, 12 hours apart.

Reply

The people in that study are definitely not on a low carb keto diet. So I'm not sure how it relates to those of us who are.

Reply

I have been on the Keto diet since Nov. 2014. I lost 15 lbs right off but have been up and down the same 2lbs for months, so I decided to try IF. This is day 6. I do 15/9, I might try to extend to 16/8 but am not ready yet. For whatever reason I can never lose my hunger. I eat my last meal by 7p and am good until about 8:30a but the next hour and a half are a stuggle. By the time I break my fast at 10a I am nauseous and have a headache. I also have a hard time with my macronutrients, no problem with carbs but keeping my protein low and my fat intake high.
Two things, one of the reasons I start my fast at 7p is because I have terrible GERD and can't eat within 3/4 hrs of going to bed and on one of the sites it says you can have a "splash" of cream in your morning coffee. I use one Tablespoon of HWC in my iced coffee but maybe should stop. Thoughts anyone?

Reply

It sounds like IF isn't for you - at least compressed eating window IF.
You might try alternate day fasting. There are studies showing that women especially do well with free eating on one day and 1/4 of that food on the next day.
You may also want to try a leptin resistance eating plan.

Reply

Thank you. I don't think I have heard of leptin resistance eating. I will research it. I just want to do something that gets me out of stall mode. If I could lose this last 15 lbs I would be happy. My husband does LC also and has stalled for the last two wks.

Reply

Make sure you really need to lose that 15 pounds. Our scales lie to us because they only give gross body weight. They don't tell us how much is lean mass and how much is fat.
Get out a tape measure and measure your waist and your hips. You want a waist:hip ratio between .7 & .8 as a woman, .7 to .75 is better. Then look up a body fat calculator. It will use those measurements and a couple more to estimate you body fat. There are also graphics around that will show you what a certain percentage of body fat looks like on the torso. Compare yourself to those to get an idea of your body fat percentage.
What I'm getting at here is that lchf eating promotes body recomposition, not just weight loss. If you've lost 30 pounds of fat while gaining 10 pounds of muscle it will look to you like you've only lost 20 pounds, which is true, but just doesn't tell the whole story.
Above all, if you let yourself become stressed out over a stall your body will ramp up all the stress hormones that make it want to hold on to fat. Even if you do still have 15 pounds of fat to lose, a stall isn't such a bad thing. Your body may need some time to readjust its metabolism to the new, slimmer you before being ready to release more fat.

Reply

I agree with Karen, give it some time and try a tape measure instead. I haven't weighed myself for a while now, I just use my clothes as a measure.

Reply

Just a thought - how much protein of you eat a day? Are you sure you're eating enough? Lack of protein may actually cause hunger issues. IF should be natural and you shouldn't struggle so it may be better if you have a small snack before bed... Here is how to find your protein intake: http://ketodietapp.com/Blog/page/KetoDiet-Buddy

Reply

hi -
Curious why you would state if you are type 1 diabetic to avoid IF completely? I am healthy & fit type 1 & can do IF no problem!

Reply

Hi Shelli, I'm glad to hear that IF has been working for you! The reason is that it would be unwise to advice all people with Type 1 to do IF. Health professionals, including those who recommend LCHF do not generally recommend IF and very low-carb diets for Type 1 diabetics. It doesn't mean they can't follow IF or LCHF at all but it means that they need to adjust their plan to fit their needs. Cases may vary and there are people with Type 1 who do perfectly fine on a LCHF diet or / and IF (by skipping meals and having a 6-8 hour eating window). So if it works for you, keep doing it, just make sure you consult this with your doctor.

Reply

I only eat twice a day,  lunch and dinner, all low carb high fat meals but I never feel hungry  even doing this.  Felt I should only eat 1 meal maybe but have been told if I do that I will not be getting sufficient  nutrients.  am over 120 kgs and have only lost 1-2 kgs in 6 weeks, but I don't exercise  due to injuries.  any suggestions  thanks

Reply

Just like me! Smile Yes, it may be difficult to get enough nutrients in just one meal (protein and micronutrients). IF doesn't always help people lose weight and you may need to adjust your macros: http://ketodietapp.com/Blog/page/KetoDiet-Buddy - make sure you eat enough protein (lack of protein will make you more hungry and may cause muscle loss). From the options given in KetoDiet Buddy, avoid those that are too low in calories (I'd usually opt for "slow" or "moderate" fat loss). Hope this helps!

Reply

Great post! Has anyone tried the plan from LeanGains? Just wondering...

Reply

Thank you Amber - I'm actually planning to try that plan!

Reply

Thank you so much!! I've been impatiently waiting for this post because I really want to try int. fasting. As always, your article is well researched, well written and comprehensive! Thank you!

Reply

Thank you Danny!

Reply

As Featured On

As Featured