Four weeks of a strict keto diet and ketone monitoring

Can ketone measurement help you lose weight and improve performance? That’s the main question I’ll be trying to answer with my four-week experiment.

See Report #1 for diet and experiment design.

Note: This experiment was done six months ago and initially only reported on my Swedish blog. This is a somewhat delayed translation!

Below are graphs of my weight and waistline over this first four-week period, as well as the results of blood and urine ketone measurements.


After two to three weeks of light nutritional ketosis, I’ve now spent 8 days in “optimal ketosis” – that is, between 1.5 – 3 mmol/L. Want to know what’s happened?

The effects of optimal ketosis


Although happy with my weight before this experiment, I’ve become noticeably leaner: -4kgs (9 pounds) and -6cm (2,5 inches) around the waist. This, of course, in complete absence of hunger – in fact, I’ve seldom felt so constantly sated. Food is tasty to eat at mealtimes, but I can skip a meal without even blinking.

My weight – initally 100kgs – was already well within normal range, considering I’m 202 cm tall – 6 feet 7 inches – and do strength training regularly. The other measurement I kept track of was my waistline. 94cm or less around the waist is considered excellent for men; I started out with 91cm, and am now around 85cm (33 inches). I need to punch a new hole in my belt, which means I’m leaner than I’ve been in a very long time. Not bad for a forty-year-old father who has limited time to work out and always eats his fill!

Mental effects

Being the father of a small child, I often get tired from lack of sleep, and during the first week of the experiment I sometimes felt even woozier than usual. This is natural while the brain adapts to running on ketones.

The last two weeks brought everything back to normal again. Or perhaps I even felt sharper and found it easier to focus for longer periods of time? Hard to tell. Perhaps it was just my imagination.

Some people have mentioned having more colourful, dramatic dreams when in ketosis – at least during the first period. I actually think this was the case for me during the first couple weeks, too.


Due to a tight schedule, my exercise has been limited to one short weekly strength routine at the gym, in the style of “Body by Science”. I take note of the weights and times I manage though, which makes it easy to compare my weekly performance.

  • The first session, following one day of strict LCHF, was nothing out of the ordinary.
  • The second and third sessions, after 7 and 17 days respectively, showed a marked performance decrease. My muscles tired more quickly.
  • The fourth strength training session, 26 days in, showed a better result than when I started.

Just as I had expected, exercise was tougher the first weeks of strict LCHF. However, four weeks in I was back at my original strength level – despite losing weight.

The combined result of less body fat while keeping (or slightly improving) my strength level reminded me of the new study conducted on elite gymnasts. Being stronger with less body fat is certainly much coveted by athletes.

Other early effects of ketosis

Another thing I noticed during the last week, i.e. during the most pronounced ketosis, is the diuretic effect. I was copiously leaking ketones (as is evident from the urine ketone levels), which take a lot of water with them going out of the body. A few of the days I drank lots of water trying to quench a stubborn thirst, and consequently paid frequent visits to the bathroom. My mouth felt dry no matter how much I drank.

Today, this is much less noticeable. Perhaps my body is adapting. Many people seem to stop leaking ketones through urine in the longer term, coupled with still being in ketosis according to their blood ketones. I’m excited to see if the same will happen to me.

A similar trend can be noted with the breath issue. The first days or weeks of ketosis, many exhale small ketone bodies, acetone. Ketosis breath has an odour reminiscent of fruit (that’s putting in nicely – others put it right up there with rotten apples), and may also be reminiscent of nail polish removers (which often contain acetone). If you find yourself experiencing this, bear in mind that it generally disappears in a couple or several weeks*. I’ll just wait and see if that’s true for me too, as I’ve had that kind of breath once in a while.

Sense of taste

Another interesting thing I’ve heard people mention during ketosis is the way they experience sweet tastes. For my part, I never drink soda and almost never eat any kinds of sweets as it is. I do however tend to enjoy fruits and berries regularly. Of course, striving for optimal ketosis means completely abstaining from everything sweet, and after doing so for a couple weeks, I one day mindlessly ate a piece of banana my daughter gave me. It felt like an explosion of sweetness. The fewer sweet things you eat, it seems, the more your sense of taste adapts.

The same principle appears to work the other way as well. Those addicted to sugar and used to consuming large amounts of sweets/artifical sweeteners daily, will have a hard time registering the sweetness of something only fairly sweet.

Transition troubles

From what I’ve read and heard, the first week of strict LCHF seems to commonly bring headaches, dizziness, tiredness, palpitations and irritability. I felt none of these things, save for a slight “woozy” feeling on some of the first days. This is probably because my everyday liberal LCHF diet should mean already I’m partly ketone-adapted. The lack of heavy transition troubles can also be because I took care to stay hydrated and get enough salt, which usually keeps the worst symptoms at bay.


This is going well so far.

  • Weight loss without hunger, even down to being very lean. It’ll be interesting to see where my weight stabilises; I’m guessing, pretty soon.
  • An overwhelming sense of satiety, which is quite practical if you don’t have time to constantly be eating.
  • The exercise routine seems to be running smoothly now that I’m a few weeks in.
  • My mental focus feels at least as sharp as before.
  • On the downside, there’s sometimes been a pronounced diuretic effect, and ketosis breath once in a while. Hopefully, these will disappear with time.

I’m going to keep this going for a while more, to try and experience the full effects of ketosis, and also to be able to perform some interesting and accurate experiments with different types of food and ketosis. More reports to come!

Previous related posts:

Lose weight by achieving optimal ketosis

A new toy measuring blood ketones

The ketone master has arrived

A keto diet for beginners

Experiment: Optimal ketosis for weight loss and improved performance

*/ For some individuals, this might not even disappear in the long term. If you’re one of those, and decide you don’t want to go around constantly smelling of ketosis, or rely on a constant supply of breath mints, you’ll probably have to settle for a more liberal LCHF diet. That is, eat some carbohydrate; around fifty grams or more a day will keep ketosis away. Unfortunately, this is a compromise, meaning you won’t be getting the maximal effect of your LCHF diet.

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  1. yuma
    Doctor, the more I read your posts, the more you make sense.

    I have a question: Suppose you are in nutritional ketosis (NK) and one day you go to a wedding and can't help yourself and eat carbs.

    I know there is damage, but how long would it take to get back to NK?


    Reply: #2
  2. Dr. Andreas Eenfeldt, MD Team Diet Doctor
    This question will be more or less answered by a later post. I tested it. ;)
  3. Galina L.
    I like how I feel in ketosis - mental clarity, stable energy , never really hungry, but it looks like everything has a downside - the more you keto -adapted, the less you tolerate carbohydrates, and that occasional cheat will sent your blood sugar higher than before, making indulgences more damaging.
  4. Elizabeth Hinely
    Can you share a sample menu for a day in optimum ketosis? Thanks.
  5. Chris
    My question is-what did you do differently to get your ketone numbers higher? I find it easy to maintain the .5 to 1.0 level, but what do you do differently to get the higher numbers, and hopefully the wightloss that goes with it. Do you purposely eat less, or add more oil to your foods? I already eat the minimum # of carbs (less that 20 per day) and moderate protein (50 grams or so a day), so I would love to know what the next step should be. Thanks for all the great info and useful website!
  6. Excellent post! I just 90 days of my own nutritional ketosis experiment and my results haven't been as dramatic as yours. I find myself stuck in the 0.5 to 1.0 mmol ketone level most of the time and my weight loss is pretty slow going.

    Reply: #10
  7. jake
    it's really cool that counting ketones in your blood isn't an eating disorder, unlike counting calories in your food. that's really cool.
    Reply: #9
  8. Regis
    I do not understand the real advantage of being in ketosis. I started eating paleo 80 days ago, but I am not restricting that much carbs. After Dr Eenfedt's opinions, increased some fat intake (coconut oil, olive oil, fish oil, butter, bacon). I'm feeling good, losing weight, not hungry at all. I would really like to understand the point of being in ketosis.
    PS.: I workout everyday - hard resistance training.
    Reply: #11
  9. Dr. Andreas Eenfeldt, MD Team Diet Doctor

    it's really cool that counting ketones in your blood isn't an eating disorder, unlike counting calories in your food. that's really cool.

    Counting calories, staying hungry and desperately trying to ignore your body's natural hunger signals forever = first step on path to anorexia and/or bulimia.

    Checking your ketone levels while eating as much delicious food as you want = path to becoming a low-carb nerd.

    Reply: #62
  10. bernardo

    Have you tried the "Bulletproof coffee" or just adding more coconut fat to your diet? I tried it the other day and I was surprised with the effect, I forgot to eat, when i notice it was 14:00. Doctor Rosendale has always recommended medium chain fats (coconut) as an inducer of ketosis and fat consumption by the body. It may help you.

    Reply: #13
  11. Dr. Andreas Eenfeldt, MD Team Diet Doctor
    The point is mainly to maximize the weight loss effect of a low-carb diet. Sounds like you don't need to.
    Reply: #21
  12. T.S
    I've had terrible nightmares since starting eating low-carb. I usually dream that I'm about to drown in coconut oil but I'm finally saved by a pizza that flows past. What to do about that ?
    Replies: #14, #24
  13. Yeah, I've tried it... 2 tbsp of coconut oil and 2 tbsp grassfed butter in my morning coffee and in the evening I made it with hot cocoa... with no real change in my ketones..
  14. This made me laugh....
  15. Armin
    I've come across statements to the effect that the ketone levels in the blood lead to higher acidity levels that the body buffers with calcium. It was suggested that prolonged ketosis might lead to calcium deficiency and possibly bone problems.Supplementation of bicarbonate or Ka, Mg and Ca (in form of citrates) was suggested.

    Any ideas on that? A real issue or just a way to produce costly urine?

  16. Simon
    How does one go about determining if you have achieved ketosis if one is unable to purchase testing strips etc? I have asked In several pharmacies here in South Africa and the looks I got from the assistants suggest I asked them for Rhino Horn (a very sore topic here at the moment with poaching issues).

    Besides bad breath and psychedelic dreams, is there anything else?

  17. alex
    Drinking a lot and peeing a lot suggests that you loose more minerals (and maybe other stuff) than normally. What do you think one should supplement to offset this?
  18. Oskars
    Hello, Doc :)
    I have tried low carb and broke after 2 weeks because my brain wasn't functioning at all anymore. Head was very heavy and i was not able to concentrate even on simple things. After eating some carbs i felt normal again. Also first week was amazing! I was feeling good and clear, my sleep was shorter, but i felt better anyways. Anyway... I broke, couldn't handle this actually very boring and i would say - very restricted diet and this i-have-no-brains feeling.
    But one thing is not clear for me and bothers me most. If glycogen is needed for muscle growth how do the muscle grow if there is no glycogen? Could someone explain me this? I am doing weight + resistance exercise in gym 4 times in week. I didn't feel any disadvantage being 2 weeks on low carb in gym (tho i skipped some of resistance trainings), i also did some of my personal records in same time. But if i cant understand this i cant use it! Dr. Peter Attia said that being on ketosis does not improves anaerobic workouts. So it means it is not suitable for weightlifting?
    Could you please explain me this muscle and glycogen thing?
    Replies: #19, #26
  19. Justin B
    Oskars, from what I understand, your body produces it if you don't eat it.
    Reply: #22
  20. @lowcarb_zealot
    Hi Doc,

    I see from your ketones graph that it looks like your ketones peak at the weekends; is this because you find it difficult to follow a strict ketogenic diet during the week when you're at work? What causes you to slip?

    Just curious ;-)

  21. Regis
    OK, so the point is accelerate weight loss. SO it is OK to eat, e.g. fruits if you do not want/need to lose weight faster?
    If yes, are there any established limits to kind / quantity of fruit intake? I read the "fruits are candy" and got a little scared... rsrsrs
    Thank you and congrats for your work.
    Reply: #25
  22. Oskars
    You mean like through process of gluconeogenesis?
  23. Shoryu
    great post!
    I was just wondering, how many calories were you consuming, and how much protein/fat?
  24. yuma
    You need to lay off the pipe!
  25. Zepp
    Its to make shure that one realy is on a ketogenic diet and dont have other disturbances how is making your body not burning fat!
  26. Zepp
    You should make a smother transitation, make it over some months!

    One dont need any glucose to build muscles.. one need energy.. and it could be glucose or fat!

    One dont get empty glycogen depoes.. one have seen that in the begining that it goes down to 50%.

    And after a full adaption.. (some months) one get about 70-80% of a carb eater.

    And if you is training that much, you should eat more carbs.. for full benefits, you burn them anyhow.. go for about 100 grams a day from healty sources.. like veggies, dairys and tubers!

    Reply: #29
  27. moreporkplease

    "couldn't handle this actually very boring and i would say - very restricted diet"

    If you do the math on many recipes from Julia Child or Louis Diat, you'll see they're about 70% fat. Add some hollandaise sauce on top to make it 85%. And we all know how boring and restricted classic French cooking is, just unedible. Absolutely.

    Perhaps you would have been more successful if you had purchased a cookbook? (wink)

    Reply: #28
  28. Oskars
    Thanks! I will definitely try it one more time on next autumn. In summer it will be impossible to stay low carb when all the home grown fruits will be around.
  29. Oskars
    Yes... Thats the feeling i have - something around 100g/day or some carb cycling should work. Also now, when i am not on low carb, i am trying to limit them anyway. I'm not counting stuff i eat - just making carb portions smaller - fat bigger - monitoring my results to see how it changes. As i said - first week of low carb was super-amazing - like on some kind dope! I believe I was depleting my glycogen or blood sugar levels - maybe that made me feel good? Maybe that was my stomach very happy not having starches?
    Low carb has very big potential it just needs to be treated very well. I would not call it simple diet... But I have learned so much from it about my self already.
    Reply: #30
  30. Zepp
    You was probably going high on stress hormones, the first week?

    If you persist to do that much exercise.. you must do a smother transitation.. others your boddy trys to rise your blood sugar with all means.. for exersice fuel!

    And on the other hand.. if one is healty, one dont need to be a low carber, just eating healty food.

    But there are much myts about carb loading.. one dont need that much, perticuly if one dont is at elit levels!

    And there are benefit about having a high fat oxidation capacity too.

    Reply: #31
  31. Oskars
    Few reasons why i wanted to try low carb
    1) And most important - mental clarity and less sleeping which some have confirmed - somehow it worked for me for a while. Now on carbs i am sleepy and cant concentrate again. It is also harder to wake up.
    2) Fat loss - i am fat. In two weeks i did not lost anything :( Same weight, same belly.
    3) Better cardio health. Hard to say, after one week low carbs i tried one of my typical resistance + weight trainings - felt as good as on carbs. Tho i had wierd hard knocing heart beats every evening before sleep.
    4) Less stress on stomach - for me it worked. Somehow i feel to heavy when eating carbs (starches?)
    I am reading and searching all the low carb info i an get to be ready for next low carb round - someday :)
  32. Cheneen
    So I bought some coconut oil, one look at it and imagining it in my coffee lead me to believe that you are yanking my chain - and my stomach did an unpleasant flip.

    About 2 minutes ago, I decided to try 1 tablespoon of oil with 1 tablespoon of butter and then add some cheese and mayo to the mix and refrigerate to harden. I will try eating it that way and get back to you.

    I hope I do not get a "gotcha".

    Do you really mix 2tbl of oil and butter into your coffee every morning? Does it not all float on top of the coffee? I suppose your answer will be "try it".

    let me go boil the kettle.

    Replies: #33, #38
  33. Armin
    Ask some old folks - a few will tell you that a slice of butter lets them enjoy their coffee because they can't take milk.

    Butter and/or coconut doesn't do much to the taste except taking the sourness of the coffee away, usually the reason why someone would use milk.

    The only thing I had to get used to was the light film of fat/oil on my lips, but that's easy. Start with a small teaspoon and then play around a little ...

  34. moreporkplease

    "my stomach did an unpleasant flip"

    I hear ya. My ancestors & nature selected for milk drinking - they worked hard for that nutritional advantage, so I'm taking it. If you tolerate milk, enjoy cream in your coffee. No need to avoid full fat dairy products if you have the genetics to digest them. Humans have evolved that capability several times independently in our history, so clearly it provides us a tremendous evolutionary advantage. Don't waste your genes! ;)

  35. Cheneen
    Thanks "Armin" and "moreporkplease".

    I had my coffee with a tsp of coconut oil and you are right, no taste at all, just a light film of oil on the lips (exactly the same as putting cream in my coffee). I was truly pleasantly surprised. Amazing how the mind can induce a thought of "no way am I doing that, and if you do I will make you heave".

    I will work my way up to Dr Eenfeldt's dose of 2 tbl spoons a day (is that the recommended dose?"and start enjoying the reduction of protein and appetite to 1g of protein per pound of lean body mass.

    Cannot wait for the scale to start moving again - that is to lower figures.


  36. Jeanne
    I get my strips online, at a Canadian pharmacy. Much cheaper.
  37. Eric Anderson
    have been tracking glucose and ketones. I will add Blood fasting Insulin so I can look at blood ketones, glucose and insulin. I have great results but I do a modified eating every other day and on my eat day aim for 378 calories from carbs (Vegetables) and 378 protien (Mostly meat) with the rest fat to include coconut oil.

    I plan to track this for 6 more months and will update. I think some others also do both ADF and LCHF.

    ANy comments or obsrvations you can share from your practice or experiance?

    Thanks Eric

  38. MerryKate
    Put the coffee, butter and coconut oil (or coconut milk) in a blender for 10-20 seconds....the fats will emulsify and the coffee lightens up, as it does when it has cream in it. No more oil slick - tastes great!
  39. Tonina
    Another great way to get your coconut oil in (which assists in achieving ketosis) is fat bombs! I make mine with 454g of coconut oil, about a quarter stick of butter, a tablespoon or so of xylitol (hardwood not corn sourced), vanilla, and unsweetened bakers chocolate or 90% Lindt dark chocolate. They are great for that little sweet tooth we get once in a while and great for a little nibble on the run.
  40. Tor
    I'm wondering if this will effect endurance? Because there should not be much glucose stored in muscles and liver if you don't eat carbs. I do boxing so I'm afraid I will perform worse if I do a LCHF diet.
    Reply: #42
  41. Galina L.
    In order to perform well in ketosis, you have to be adapted to it. It took me several months, but as a result my endurance significantly increased. I don't know how well my experience translates to others - I am a 50+ female.
  42. Zepp
    As alredy sayd, one have to do the transitation first.. and under that period you get less anaerobic perfomance.. it force your body upregulate your fat burning capability!

    Then, after that you can always ad some more carbs.. preferly such that have other nutrients too, becuse its easy to fill up ones glycogen depotes, but it doesent matter if one dont fill up ones healt depotes!

    The benefits of LCHF is often better endurance, becuse one can use both glycolysis and betaoxidation.. and not only glycolysis!

  43. Emil
    I have been on LCHF for the last 5 years. However, for the last 4 weeks I've been eating to minimize insulin as much as possible to get a bit leaner. I would like to get to about 7% body fat.

    I eat according to the following rules. Rule 1 may override rule 2 and rule 2 may override rule 3 etc.
    1. Eat 100 grams of protein on days with 1 workout, closer to 150 grams on days with 2 work outs. Do not go over or under these numbers.
    2. Eat protein only when insulin is low. Insulin levels can be approximated by blood glucose or ketones.
    3. Do not eat more than 50 grams of protein per meal. Closer to 30 grams is ideal.
    4. When hungry eat fat.

    I also eat 1 tomato covered in salt at each meal.

    I go to the gym and lift weights 8-10 times a week (sometimes twice a day).
    I have huge amounts of energy all the time and even after my hour session is up I usually would like to keep going. I spend the whole day behind a computer and if I do not go to the gym that day I feel uncomfortably energetic. I often train having not eaten dinner the night before and not having eaten breakfast that morning. In this case I find my ketones are super high, I am very thirsty in the gym but there is no decrease in energy what so ever. One more thing, on a diet with a bit more protein and carbs (but still what most consider low carb) I would always get light headed after performing big exercises like squats or dead lifts, this never happens anymore.

    There certainly is an adaptation phase every time you lower carbs+protein but after you get past that you will never look back. I am a fat burning machine.

    Reply: #56
  44. Tony Nguyen
    Great experiment. It is hard to do this but it is necessary.

  45. Alexander
    Dear Doc: I have heard a lot of buzz about targeted ketogenic diet. Is this a modified version of the standard ketogenic diet? It entails carb loading in the morning, before and after workout. Also it permits a cheat day every week.
    I am confused by all these different formulated ketogenic diet versions. According to The art and science of low carb performance, carb loading or high protein supplements post workout actually suppresses ketogenesis.
    Please clarify these confusions for me, thanks so much!
    Reply: #46
  46. Zepp
    Im not Doc but.. there are different ketogenic diets for different purposes!

    Diabetics take one approche, healty persons that need too lose weight take another.

    Athletics take others.. they often use carbloading days to fill up glycogen and have glucose for anaerobic activitys.

    Typical is.. body bouilders use it for deff, they have a carb day a week typical.. in that period.. othewise they often bulk on carbs.

    Endurance athlets often use targeted ketogenic diet, they use "train low, race high"!

  47. Candresen
    I've been following this plan for four weeks. The first week I lost 2 lbs. Nothing since then. I'm keeping under 20gm of carbs. Any suggestions? I really want this to work so I keep holding out that it will.
    Reply: #48
  48. Zepp
    First you lose some water.. then moste of it comes back.

    It takes four weeks for your brain to be able to take up to 70% of its energy frome ketones.

    Then it can take months befor your muscles get use to use fat as predominant fuel.

    In the meantime your ability to use stored fat as fuel betwen meals upregulates.

    Take notise about your apetite.. if you use more of storde fat your apetite get lower.

  49. ridoy rahman
    This is natural while the brain adapts to running on ketones.
  50. chayal
    I have been on LCHF for past 3 weeks and lost 4 kgs.
    I am 23 yrs old,163cms tall and presently weigh 61kgs.(when i started it was 65kgs).
    Now the wieght loss is not taking place.
    Also I am going for a trip where I wont be able to follow the diet.
    So how to quit the diet without gaining weight?
    I do swimming and cycling(10kms) everyday.
    Please help!!!!
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