Keto Diet App - Free Download Keto Diet App - Free Download
Take the guesswork out of following a low-carb diet, lose body fat & feel great!
KetoDiet app is FREE to download!

Complete Guide to Intermittent Fasting

4.9 stars, average of 801 ratings

This post may contain affiliate links, see our disclaimer.

Complete Guide to Intermittent FastingShareFollow us 261.1k

Table of Contents

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 dependent 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 your 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 to reach your daily macronutrient targets 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 months-long weight loss plateau. Although Intermittent Fasting is not always a guarantee for weight loss, it has proven to have several health benefits.

Complete Guide to Intermittent Fasting

IF versus Calorie Restriction

Most studies compare intermittent fasting to calorie restriction in the sense that both have several health benefits. (1) 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 ( 2) and may also cause severe micronutrient deficiencies. This is, of course, relative and depends on the scale of the calorie restriction.

A study of mice compared IF and calorie restriction and found that IF exceeded the beneficial effects of calorie restriction. ( 3) Another study compared individuals on IF and calorie restriction and found both to be equally effective for weight loss, although IF was better. ( 4) 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.

How Does it Work? Types of IF

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

Healthy low-carb eating is great for appetite control and keeps you 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 meals high in fats, moderate in protein and low in carbs induce strong satiety.

Complete Guide to Intermittent Fasting

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) Alternate days of calorie restriction with days of unrestricted eating while still eating low-carb food

This approach may be easier to implement than a day of complete fasting. You reduce your calorie intake by 20-30% on one day, followed by unrestricted eating on day two.

6) 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 and cardiovascular markers, increases insulin sensitivity and reduces blood pressure and inflammation markers. ( 5, 6,  7)


Several studies that were performed on mice showed increased lifespan when a period of fasting was included in their diet. ( 8) The most likely reason for that is that fasting affects the ageing process via calorie restriction. Another reason for increased longevity may be the fact that fasting improves the symptoms of metabolic syndrome (obesity, diabetes, etc.) and reduces the risk of cancer.

Also, fasting and ketosis have been 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 been shown to enhance production of growth hormone which is known to naturally decrease as we are ageing. (9)

Complete Guide to Intermittent Fasting


A review of studies has shown that metabolic factors are strongly linked to various types of cancer. 10) The strongest risk factors identified in men were high levels of blood pressure and triglycerides, and in women' high plasma glucose. Since IF improves metabolic syndrome markers, it also reduces the risk of cancer. Additionally, another study shows that fasting helps reduce the negative side effects of chemotherapy in cancer patients. ( 11)

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.

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, some studies show that intermittent fasting increases fat oxidation. ( 16) 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 have found that on days of IF, I naturally eat 20-30% less. I tend to eat less on the days I skip exercise or days without IF, or a combination of both.

What is more effective for weight loss? Calorie restriction or Intermittent Fasting? A 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. ( 17)

Improved Fitness

When you exercise in the fasted state, you'll enhance fat burning. 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 ( 12,  13). 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 ( 14,  15).

Complete Guide to Intermittent Fasting


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 with Intermittent Fasting

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. Is 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) "Bulletproof aka butter coffee" will break your fasting period

Ingesting butter and coconut oil or 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.

Complete Guide to Intermittent Fasting

5) 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.

6) 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.

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 (as 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 fits 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.

Complete Guide to Intermittent Fasting

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, these nutritious low-carb and keto recipes are suitable for those who practice intermittent fasting and only eat one or two meals a day.

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

Do you like this post? Share it with your friends! 

Martina Slajerova
Creator of

Martina Slajerova

I changed the way I ate in 2011, when I was diagnosed with Hashimoto’s, an autoimmune disease that affects the thyroid. I had no energy, and I found it more and more difficult to maintain a healthy weight.

That’s when I decided to quit sugar, grains, and processed foods, and to start following a whole-foods-based ketogenic approach to food.

About the Reviewer

This article has been reviewed by Franziska Spritzler, RD, CDE who is a qualified expert. At KetoDiet we work with a team of health professionals to ensure accurate and up-to-date information. You can find out more on the About us page.

Let us know what you think, rate this post!

Leave a comment

Note: Any links to products or affiliate links will not be approved.
Please note that we do not offer personalised advice. For any diet related questions, please join our Facebook community.

Comments (131)

I regularly have coffee with 1 T hwc in it at about 9am and another about 10am. I don't usually eat a meal until about 11am. Should I count 9am as the starting point for my IF Day?

That's a tricky question. 1 tablespoon of heavy cream contains about 55 calories which is borderline fasting-approved. But if you have 2 cups... I would personally count the coffee in (as non-fasting).

Martina, this is an excellent write up you put together here, and I'm interested in some of the discussions I've seen about 12hr, 18hr, and 23hr intermittent fasts, if there is some benefit to that.  
You also mention taking your carbs all in at once, and I find it is pretty tough to just have a zero carb meal - eating steak or skinless chicken is one way, but gets boring you have any tips for getting low carbs but a great variety in the meals during the non-fasting hours?

Hi Andy, I don't do more than 18-hour fasts (mostly because of my thyroid condition). You can find more about benefits of fasting here: 7 Science-Backed Health Benefits of Fasting
And more about types of fasting: Practical Guide to Fasting
When it comes to carbs, it depends on your daily carb limit. If you eat 25-30 g net carbs, then it's better not to have them all at once. If you can have this in 2 meals (skipping just one meal), then you are more likely to tolerate this level. If this is too much, then you may need to reduce that to about 10 g net carbs per meal. Foods like avocados and leafy greens will help you keep your net carbs low. I hope this helps!

I have Hashimotos and have been following keto for about 6 months.  The first three months, I lost great.  I've been stalled for the second three months.  I'm on day 2 of IF.  Since you also have Hashimotos, I thought I'd ask for advice.  I'm probably in the group of Premenopausal women Mark Sisson writes about.  Have you personally experienced benefits with IF with Hashimotos?  Do you know of other premenopausal women with Hashimotos who have?  I'd love to end this stall.

I just had a question after reading several of your articles. I’ve been doing IF 16/8 and recently 20/4 as I am just not hungry. I know my macros etc, but if one is fasting 2/4 what percentage of your macros should you be meeting? There is no possible way to meet the entire criteria as at 20/4... I’m full & literally feel like I want to vomit after I eat. I typically eat high protein high fat, low carb meal after my fast.

I started fasting 2 to 3 days, then eating me to style last month. This month I fasted 5 days and lost 10 lbs. I feel great and am more incuraged to stick to my keto diet

Great article! I loved it. I have a question, though: because of my work schedule I can only workout in the morning. I am big fan of p90X and Insanity. So, I wake up at 6am, drink a black coffee with ghee butter and some collagen and then work out. After that, I eat a keto-balanced breakfast. So, for me, a morning fast is not really an option. I do eat my last meal at 7pm the night before, so I am not eating anything until that first morning coffee at 6am. So, if I keep my morning routine and then I skip lunch and have dinner 12 hours later, does that qualify as IF? It feels like all of it is kind of half way, so I am not sure...
Thank you!

Hi Martina, great article!
I understand that IF puts you in ketosis.
I was wondering if you can eat leafy vegetables during your fast and stay in ketosis?
I do a 16:8 protocol and sometimes find it difficult to eat the amount of vegetables I'd like to in that period. Would it be okay to eat, say, a head of lettuce or a few cucumbers during the fasting period, or would they have too many carbs?

Hi Rory, leafy greens are very low in carbs and unlikely to have any negative effect on ketosis. Having said that, it's worth checking the nutrition facts (net carbs) as not all vegetables that are green are low in carbs (e.g. leeks, Brussels sprouts or broccoli can add up).

Thanks for the reply Martina!
That sounds good. I checked the nutrition facts and a head of lettuce (360g) is 10g carbs, with 4.7g of that being fiber. Ketosis is one of the main attractions of IF for me so this is good news. Thanks again.

How long should a person fast for? and, is it different for men and women?

I'm not a fan of prolonged fasting and I don't do more than 18-fasting/ skipping meals due to hypothyroid issues. Women in general should avoid prolonged fasting. Here's more info about fasting: Practical Guide to Fasting

Hi, 2 1/2 months into keto dieting and I've lost a stone thanks to Martina's blogs, apps, and recipes. I have always been in the healthy BMI range but it was leaning towards overweight and it was time for change.
I thought I'd share the key points that's helped me successfully shed and maintain my weight (which Martina has kindly imparted in her blogs):
1) Read and understand what LCHF diet is and whether it is for you as it is not temporary and requires a permanent change in your dietary lifestyle.
You should know what ketosis, net carb, keto-flu, intermittent fasting, and fat fast means prior to embarking on this diet.
2) Always record what you're eating and monitor your daily macros. The KetoDiet app helps with this.There are thousands of DELICIOUS low-carb recipes online...record your favourites in the app.
3) Set a realistic daily carb intake limit (mine is 20g) and try not to exceed your limit and the limit that knocks you out of ketosis.
4) I preferred the taste of Xylitol to Erythritol BUT lost weight faster when I switched to Erythritol.
5) My weight plateaud for 4 weeks but I continued on and lo and behold the weight started dropping again. Intermittent fasting as part of your lifestyle helps.
6) Eat when you're hungry, don't if you're not. Always have fat bombs and cooked meat at hand.
I love good food and I love cooking and this diet simply feels effortless!
Thanks again Martina and happy eating everyone!

Thank you so much for your lovely feedback and tips!

I'm a type I diabetic and a combination of keto and IF has probably literally saved my life.  My blood sugar and all of my other labs have been near perfect over the 6 years Ive been doing it.  I went keto first, and quickly moved to two meals a day at around 2pm and 7pm, then dropped the 2pm meal because I wasnt feeling hungry at that time.  I have lost around 90 pounds (maybe more, I never weighed myself at my highest) and have maintained it to within 15 pounds for the last 2 1/2 years.  
I just wanted to say that I really hate it when I see people online authoritatively shooing type I's away from this way of life.  There is absolutely no truth to this being bad for either t1 or t2s.  None!!!

Finally! So many people tell me it’s dangerous. Please! For the first time in 15 years my sugars are normal. Have you been able to find any good keto - type 1 q+a sources? I’d love to know if correcting hypoglycemia affects ketosis. Questions I can’t seem to find answers to cuz no one seems to know.

Can we have BCAA, Creatin in IF?

I have a question. If I'm fasting for 16 hours and eating for 8, can I still drink water or tea in my  16 hours fasting period? Or liquids are still count as a meal? Let's say if I drink water or tea from 10am-12pm and eat food at 12.30pm, do my 8 hours start at 10am or 12.30pm? Please help and thank you very much for your blog! 😊

Anything under 10 calories won’t break your fast! Regular tea or black coffee is perfectly fine. It’s actually recommended to drink black coffee in the morning to boost energy levels and satisfy hunger a bit. The only thing with calories that is good to take while fasting are 10g or less of BCAA. Usually to power through a workout

You can have water and plain tea.  Also pickle juice--anything without calories is fine.

Do I have to still hit my macros on IF or does it matter?

You don't have to unless you do IF every day. Then you may need to keep an eye on your protein intake (you should be getting enough).

Is it possible for a skinnier frame guy who's not looking to lose weight but rather to gain muscle, a good fit for IF? If so how and what needs to be done! Always had an issue gaining weight and muscle!

Yes, you definitely can. Check out the link to LeanGains (above in the 3rd type of IF). If your goal is to gain muscles, you may have to do cycles, depending on the gain you are aiming for.

Hi. I'm on keto diet and my problem is: I feel hungry and eat only 3 times/day. SOme days I eat only meat and some lettuce and tomato. Is it ok? Or do I haveto stick sharply to all the menu? I eat multivitamin every day.

If you feel hungry and eat 3 times per day, it's perfectly fine! You don't have to do IF - you shouldn't feel hungry. Or maybe your meals are not satisfying enough? You should introduce a variety of foods into your diet: Complete Keto Diet Food List: What to Eat and Avoid on a Low-Carb Diet

I decided that I needed to lose weight because my mum was fattening me up with american dinners and walking it off wasn't doing much too get my weight down.
I chose to eat tinned mackerel and packet  
noodles too make a fish soup and snacked on guacamole and corn chips and some occasional chocolate.
I reduced my food intake to one meal a day plus snacks and increased my walking too two long walks a day without distractions from contraptions like mobile phones or pesty pets and no television at home too distract from my focus of what I was doing.
It is grueling work for your body but I did start to see the beneficial side of it and I also stopped using drugs and this sort of body cleansing meant I didn't get sick and didn't need medication to keep me going.
If you follow the basic guidelines of what they say in the IF programme you will be thankful you did and your body will appreciate it, but you can put a little twist on it if you think it'll help and a lot of people do it differently anyway.
Good luck with your fasting and enjoy your time doing it.

I'm wondering if its Ok to have Electrolytes during the fasting period. I've been told that the only permissible drinks are Water, Coffee and Tea. However, I feel like the only thing my body is craving  are electrolytes. Would I be kicking myself out of Ketosis if I drink some electrolytes ie.(Potassium, Sodium and Magnesium)?

I think you should drink electrolytes - you can make a sugar-free drink that is very low in calories and suitable for IF: Beat Keto-Flu with Homemade Electrolyte Drink

I really enjoy breakfast each morning when I get up but also want to enjoy dinner with my family.  Can I really experience the benefits of IF if I'm only skipping lunch? Everything I see encourages all calories in a blocked time frame of 4-6 hours.

Yes, you can. Some people prefer skipping breakfast, some lunch and some dinner (I'm the breakfast type). You don't have to fast for 16 hours to see the benefits - you should do what fits best your lifestyle.

Hello, can I drink lemon water  while I am on IF?

Yes, you can, as longs as it's no more than 50 calories.

So, chicken bouillon would be ok during the fasting period?  😊

Yes, this includes chicken stock 😊

A friend of mine is using a Keto and IF plan and his window of eating is only very late at night before bed. Everyone he works with has noticed a major change in his attitude (super grouchy!) and he seems soooo unhappy. He's definitely lost a lot of weight but I'm afraid he's just not ingesting enough calories to get him through the day and it's making him incredibly tired. Is part of this plan to fast all day along with lifting weights and living your entire day hungry and tired? It doesn't seem like a healthy way to lose weight to me if it makes you suffer all day and then gorge at night.

I'm sorry for the delayed response. Yes, you can do heavy lifting when you do IF. I don't personally fast al day, and although I may not have a "post-worjout" meal, I just skip meals (14-20 hours of fasting depending on how hungry I get). I follow my appetite and keto is a great way to control it You should not suffer when you do IF and eat when you are hungry. IF to raise my drinking coconut water during fast can hindrance HGH growth? Because its meet the hungryness? Or its ok to take this during IF for HGH? Coz we hv lots.of coconut near market (: ..or its better to drink this after break of IF? Tnx..

I have been doing low carb for 3 months and IF for one. I am amazed. I am never hungry like I used to be. I have a recent back injury that has severely affected my ability to exercise I got up to 230 lbs. In the  first 2 months of of low carb only I lost 9 lbs bringing me to 221. Today after 1 month of IF I have lost an additional 11 lbs. this is with no exercise. I began with a regular 48 hour fast. I then began fasting 20 hours a day. I drink 8 regular bottles of water at least. I remain on the low carb during my four hours of eating. I only eat til satisfied. I stay full. I have followed your reccomendations and have had no side effects at all. My energy level is much better and I feel sharper. I am hoping the weight loss and other benefits of IF will help with pain and healing from my injury. I definitely feel more positive and better about myself. Oh as far as anti aging. My doctor has told me he has never seen a bone fusion heal so perfectly. My family has accused me of having oral done on my face as my skin is so clear and hydrated compared to before. Thank you so much for your info and links. You have helped change my life at one of the worse point. Namaste!

Hi Mike, thank you for sharing your experience and tips!

Hi. I'm on keto diet and my problem is: I feel hungry and eat only 3 times/day. SOme days I eat only meat and some lettuce and tomato. Is it ok? Or do I haveto stick sharply to all the menu?

Where's your Fat? You didn't mention it. It's so important to keto. Are you frying your meat with butter or coconut oil. Are you having a sweet fat bomb for dessert. Fat will make you not hungry. Go to a keto calculator online. You put in your info and get your calorie, protein, carb and fat amounts. Keto is not a calories reduction diet. You do consume less calories but you must eat your protein and fats.

Hi Igor, check out your macros here: KetoDiet Buddy - Easy Macro Calculator for the Ketogenic Diet

Hi Martina,
I am not really sure how to calculate my fat percentage to add to this Keto Diet Buddy calculator. Is it a guess on how much fat I have on my body? 😊
Thank you.

Hi Toni, I think these will helps 😊
About calculating body fat (includes comparison photos): How To Measure Body Fat
Here's how you can calculate your body fat percentage using skinfold calipers: Body Fat Calculator

Do you think that BPC, consumed daily,  can actually stall weight loss? I have a cup in the morning and then usually eat around 3pm my one meal a day. Maybe a snack a little later but I feel with so little food, I should be seeing some weight loss but I simply cannot shed the weight. I did some reading on the effects of coffee on cortisol. Combined with the my muffin top I cannot seem to get rid off, I have come to the conclusion that maybe BPC is not good for me. I also exercise daily and eat plenty of protein.

Yes, it can indeed. I listed BPC as one of the possible reasons for weight stalling: How To Low Carb: 15+ Common Weight Loss Mistakes
However, in your case I doubt it's the BPC that causes it. If you only eat one meal a day (plus BPC), I doubt you are eating too many calories. It may actually be the opposite - you may not be eating enough.

I have a question about the Active individuals, IF combined with exercise. I have been doing LCHF since thanksgiving and I keep losing and gaining the same 3lbs. I wand to try the IF fast combined with exercise. You said to eat more carbs on workout days and my post workout meal should be the largest. What carbs do you recommend and if I eat a higher amount of carbs post workout would this take me out of ketosis?

Hi Shalah, carbs are not always necessary, it depends on the workout you do, and also on your goal. If your main goal is to gain muscles, then post workout meals are more important than when you want to lose a few pounds of body fat. In that case, you can even skip post-workout meals and have a meal when you feel hungry. You should never force yourself to eat. When you exercise, you will naturally eat more compared to your "resting" days.
Here's more info: Ketogenic Nutrition and Exercise: Carbs (includes the types of foods I'd recommend)

Load more comments, 80 remaining