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Paleo and Keto – What’s the Difference?

I just answered this question in a forum over at, but the answer also makes for a good blog post, so here we go:

“Paleo” simply means that you try to eat what your ancestors ate in the paleolithic era, which essentially means “before we had agriculture”. It’s a very vague definition, and so there’s a wide range of foods that are included at least in somebody’s definition of paleo, but not in another’s. Typical bones (pardon the pun) of contention are dairy, legumes, ancient/wild grains (quinoa, amaranth etc.), tubers (roots) and so on. Regardless of those details, on a Paleo diet you usually focus on food quality first and foremost rather than macronutrient ratios.

“Keto” on the other hand has a clear definition: Any diet where you eat very little digestible carbohydrate (typically <50g/day of net carbs) and moderate protein (about 100g/day for an average person) will cause your body to produce ketones in the liver, and your brain will switch to burning these preferentially instead of glucose. There’s a host of other changes which happen during ketosis, but in a nutshell you indeed switch from carbs to fat, and at least during weight maintenance (also called a eucaloric diet, you eat as many calories as you burn) about 70% of your calories come from fat (a mix of mono-unsaturated and saturated fat).

So – do those two diets overlap? Sure. You can definitely implement a ketogenic diet using paleo foods – in fact that’s what in essence all the popular books on low-carb / ketogenic diet books advise: Focus on whole foods, organic, grass-fed, steer clear of processed foods. Keto by no means implies a meat-heavy diet – you can even implement it vegetarian style while still remaining paleo. Vegans will have a hard time, since complete protein is hard to obtain once you eliminate rice and legumes, but they can get there using fermented soy – which is technically not paleo, but fermentation itself is thought to have been used for a long, long time, so if not strictly “paleo” you can look at it as an “ancestral” technique.

So how would a typical keto+paleo meal look like? Imagine a huge salad made from leafy greens and non-starchy vegetables, with a little bit of meat,fish,seafood,dairy or eggs, and liberal amounts of butter, olive oil, avocado or coconut oil (fat), with maybe some nuts sprinkled on top and a hand-full of berries for dessert. Typical macros for a Keto weight maintenance diet: 70% fat, 20% protein, 5% carbs.

You can also use this neat calculator to figure out your optimal ketogenic diet macronutrient composition depending on your goals:


When the goal is fat loss, on a ketogenic diet the idea is to keep carbs and protein constant all the time and simply reduce the amount of fat you eat. Your body then “supplements” that fat it needs from its own fat stores, which it can easily access since in ketosis you burn fat more easily than you would on a diet higher in carbohydrate.

Fat Loss Diary: Moving on to Alternate Day Fasting

So last week I started intermittent fasting … but I only managed to implement two fasting days, in line with popular books like The Fast Diet, the 5:2 diet etc.. It worked well, but I read two more books on the subject which convinced me to move on to a “proper” alternate day strategy. One of these books is a German/Austrian book called “Die morgen kann ich alles essen Diät” by comedian Bernhard Ludwig – the other one, which I found more interesting as far as the scientific arguments are concerned is Krista Varady’s The Every Other Day Diet. I knew Krista Varady from Michael Mosley’s BBC Horizon episode on fasting – he interviewed her and ended up tweaking her protocol (one day of calorie restriction alternated with one day of normal eating) for his book. She didn’t appreciate that – in her opinion having two feed days in a row may have a disruptive effect on your ability to automatically restricting calories on feed days. So reducing the number of fasting days per week in order to make the diet easier to implement may actually undermine its efficacy – even more so in maintenance mode, which in The Fast Diet works by reducing the number of fasting days to one per week, but in Krista’s book works by increasing the amount of calories you can eat on fast days and keeping the weekends “fast-free”, but you still have three fasting days per week.

Looking back at my week I can – in a very uncontrolled n=1 way – confirm that 2 fasting days per week is problematic. I fasted on Monday and ate normally on Tuesday, and wanted to fast again on Wednesday – but something got in the way (work lunch), so I decided to push back the second fast day – no problem, I can put my fast days where I want, right? Sure … I ended up just barely getting in the second fast day on Saturday, and between the fast days I overate. I still probably ended up with a caloric deficit for the week, but in retrospect I think that using a strict alternating strategy leads to much better compliance at least for me. Clear rules! You can still eat a small meal each day, so a work lunch is doable (salad + some protein).

So for this week I’ll be alternating properly: Monday, Wednesday, Friday and Sunday will be fast days with no more than 500 calories, Tuesday, Thursday and Saturday will be unrestricted. Next week will be the other way round – which some people find disturbing because they need regularity but which I find quite cool actually. One effect is that your weekends alternate – on some weekends you get to eat on Saturday, on others you get to eat on Sunday.

So that’s all for this week – we’ll see how strict alternate day fasting works out for me!

Fat Loss Diary: Intermittent Success

Last week I announced that I would try intermittent fasting – and I did. I fasted on two non-consecutive days, and ate normally on the other five. Unfortunately I did not lose any weight – but I had been on a low-car calorie restricted diet the week before, so that could be due to re-gained water weight.

In retrospect I found some things which I could improve: 

  • The weather wasn’t good, so I used the car a lot
  • The week before I had gone on long walks after lunch, not so last week.
  • I ate a lot of chocolate and fruit on the non-fasting days. This is allowed on the 5:2 protocol
  • I didn’t count calories except on fasting days, which is also encouraged by the popular books on intermittent fasting

It’s hard to say which of those things matter more, and if I was doing a scientific experiment, I would have to change one of them at a time and keep everything else equal in order to find out. Fortunately I’m not, so I’ll change a bunch of things for this week:

  • I’ll use the bicycle every day to drive to/from work (16km)
  • I’ll walk at least 8,000 steps every day, and climb at least 20 floors (as monitored by my Fitbit tracker)
  • I want to achieve a nice caloric deficit for the week (about 7000 calories), so I’ll …
    • be more strict on fasting days (zero calories)
    • count calories every day
    • Three fasting days instead of 2
  • I’ll do HIIT (high intensity interval training) every other day. Eventually I want to do tabata intervals, but doing those every other day would kill me, so I’ll go for 4 20 second sprints with 30 second pauses between instead of the full 8 20 seconds with 10 second pauses of tabata. In time I will try to work up to doing one proper tabata workout per week.

 That’s it – stay tuned for next week’s update!

Fat Loss Diary: Ketosis, Interrupted

Last week I proudly announced that ketosis (ultra low carb) was working fine for me – well, it did, and then it didn’t anymore. Some may find it weird that I purchased a glucometer as a non-diabetic (my parents surely did), but I don’t regret it, because it revealed that after the third week of being in ketosis, my blood sugar level increased. In the beginning it had been lowish (80-90), but after three weeks of ketosis it had crept to the high end of the range which is still considered normal (100-110). I was mildly annoyed – after all, I wasn’t eating any carbs, so where did the glucose come from? I wasn’t eating a lot of protein either, so the body has to make the glucose from its own protein (bad) and from the glycerol in the fat stores (good, but that only accounts for a very small amount).

So what should I do? A quick consultation of Dr. Google didn’t provide any useful clues – there were many advocates of ketosis making inconsistent arguments – on the one hand they were praising ketosis for lowering blood sugar, on the other hand they were talking about a supposedly benign phenomenon called “physiological insulin resistance”, which leads to increased blood sugar levels. What gives?

Read more…

Fat Loss Diary: Full On Ketosis

Last week I mentioned that I had rediscovered nutritional ketosis – and today, one week later, I’m still in this fascinating state of fat burning. So far it works great – I’m eating very few calories and at the same time am not feeling hungry at all (because my body is augmenting my food intake using its fat stores). I’ve also been testing my blood sugar level as well as ketone level (Beta-Hydroxybutyrate) on a daily basis, confirming that I’m actually in ketosis. My blood sugar is hovering around 80, while the ketones are around 2 mmol/L … I seem to have no problem entering and maintaining ketosis, which seems to be a major problem for some people. I quickly learned that I can eat berries and dark chocolate in small quantities without any effects on the ketosis, which makes this diet a walk in the park as far as adherence is concerned.

I think I made one small mistake: I added salt and mineral supplements to the diet because a lack of those micronutrients is frequently reported when adapting to ketosis. I think that this had some unpleasant effects on my digestive system – so from now on I won’t do that anymore and instead wait for when (and if) I develop symptoms (dizziness when low on sodium, muscle cramps when low on magnesium etc.). The same goes for fluid intake: instead of drinking a lot of water throughout the day independently of thirst, I will only drink (water) when thirsty.

The same goes for food: Today for example I had the problem of not wanting to eat anything. My biggest worry is that I’m not getting enough protein, but I’ve now been in ketosis for two weeks – it’s quite likely that my body is no longer converting protein to glucose. I’ll definitely try to go for 80g of protein per day from now on – and a bit more on exercise days.

Beitrag zu Low-Carb im ZDF: Purer Unsinn.

Hallo zusammen,

heute mal ein Post auf Deutsch, da ich in der ZDF Mediathek auf diesen Beitrag gestoßen bin und ich beim Anschauen fast meinen Fernseher aus dem Fenster geschmissen hätte – bei so viel Unsinn muß ich einfach was dazu schreiben.

Hier der Beitrag:

Im Video geht es zunächst um ein Low-Carb Café – das finde ich zunächst mal eine gute Idee, wobei immer die Gefahr besteht, daß die Ernährung zu einseitig wird. Anders ausgedrückt: Wer zu Low-Carb findet, weil der Blutzucker/Insulin Mechanismus durcheinander kommt und als Resultat eine Abhängigkeit/Sucht nach Süßigkeiten entwickelt, tut sich vielleicht keinen Gefallen, Low-Carb zu machen und dabei dann seine Ernährung auf “Fake-Carb” umzustellen – Sachen wie Low-Carb Brot, Low-Carb Kekse, Low-Carb Kuchen sollten die absolute Ausnahme darstellen.

Aber darum geht’s mir in diesem Post eigentlich gar nicht – sondern um den restlichen Teil des Videos, in dem Low-Carb diskutiert wird. Hier würde ich gerne die Argumente von Ernährungsberaterin Brigitte Bäuerlein aus dem Video direkt zitieren und kommentieren: Read more…

Fat Loss Diary: Rediscovering Nutritional Ketosis

It’s been almost two weeks since my last post … and a lot has happened since. In the first week I was implementing the strategy that I had laid out, which was essentially low carb, no snacking, intermittent fasting. It worked – but I began to browse through my extensive collection of books on low carb and actually got a few new ones, and I watched many lectures on YouTube. For a while I got a bit frustrated because I came across so many ideas which I (now) know are false, plus some exciting new hypotheses, most of them sounding too good to be true. After a while things began to clear up though, and one idea stuck:

Nutritional Ketosis

This is essentially a very low carbohydrate diet. I could simply link to the Wikipedia entry for ketosis, but this time I’m going to describe the concept myself: If you go on a diet which is very low in carbohydrate and reasonably low in protein, the body quickly runs out of stored carbohydrate. This is because humans can only store a small amount of carbohydrate in the muscles and in the liver, which in itself tells you something about what’s the preferred fuel for the body (by comparison there’s a virtually unlimited store of fat). In the short term the body tries to compensate by creating glucose (the “currency” of carbohydrate in the body) from protein and fat through a process called gluconeogenesis. After a while (2-3 days) though the body begins to produce ketone bodies from fat in the liver. As it turns out, when there is very little glucose available, the  most important organ in our body which under “normal” (high-carb) conditions relies almost exclusively on glucose – the brain – can switch to ketones as an alternative fuel source. It still uses a small amount of glucose, and other cells in your body continue to rely exclusively on glucose (for example the red blood cells), but all things considered, once the adaption to ketone bodies as a fuel source is made, there is much less need for gluconeogenesis. Being in that state (also called “keto-adapted”) is called nutritional ketosis.

Why is this important for my fat loss diary? Read more…


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