Carb Back-Loading Pearls and Criticism

CBLCarb Back-Loading Pearls and Criticism


Listened to the most recent podcast with Kiefer on the Optimal Health Show with a fantastic summary of Carb Back-Loading and a great discussion on the science behind it with info that wasn’t included in the book itself.

Some of the pearls and nuggets dropped:

  • When keeping insulin at low levels in the first half of the day, this activates the enzyme hormone sensitive lipase in fat cells which allows them to release more fat and deactivates the enzyme lipoprotein lipase which prevents fat cells from storing fat.  I know he’s referenced these enzymes in both Carb Nite and Carb Back-Loading but never really mentioned their names.
  • It turns out Crossfit is ok with Carb Backloading.  At around the 9:30 mark he discusses power production training which includes resistance training, Crossfit, and certain body weight exercises at later in the day when the body is more insulin insensitive will allow the use of ingested carbs without depositing them into fact cells.
  • When insulin is elevated, your body won’t let you access internal glycogen stores and body fat, and instead relies most heavily on what was just ingested.
  • When insulin is low, your body can then access internal glycogen stores as well as stored body fat, and you muscles are more sensitive to stress hormones, allowing greater strength output when training.  This is why it’s better to train in a low-carb / low-insulin state.
  • Would like people to have ketones in the 3 mmol range during early ultra low carb portion of the day.
  • Some people like to use white rice and honey for back-loading…

Here are some more gems from Kiefer’s own latest podcast (Body IO FM Episode 7) where he does a Q&A session:

  • He does not buy into all the ‘resistant starch‘ hype because we just don’t know enough now.
  • Dr. Patel has used resistant starches on days when he eats carbs and hasn’t noted any difference in feeling or his blood glucose measurements at all (apparently he is using continuous glucose monitoring).
  • Leucine can be used to spike insulin without carbs post training, since it’s the insulin that’s the most important factor in carb back-loading.  5gm is optimal post workout.  Can use an additional 5 gm later on in the evening with subsequent meal.
  • If you accidentally go overboard on one carb nite, when the next carb nite rolls around and they still haven’t lost weight, leucine can be used instead of eating carbs.  5-10 gms is ideal, especially when used with a protein shake.
    • This is the first time I’ve heard him suggest using weight as a guide to knowing when you go overboard on carb intake… and to use this information to regulate how much you eat on following carb days.
  • Some people actually inject insulin after training!!  While this is super super super dangerous, apparently this gives similar results to carb back-loading.
  • Questioner who’s interesting in losing more body fat, is following Carb Nite while doing Wendler’s 5/3/1 and finding that he’s gassing out in workouts mid week wants to know if he should up his carb intake.  Kiefer’s answer is just to back off on the workload on the days that he’s gassing out.
    • When resistance training in absence of carbohydrates, training volume should only be 40% of what it is when eating carbs… so the 5/3/1 paradigm is not appropriate, it should instead be scaled back.
    • A good tool to track this is Joel Jamison’s Bioforce HRV… (can’t believe this thing popped up again… really makes me want to play with it)
  • For women with questions, there will be a Carb Back-Loading book coming out just for women soon, but until then, this episode (Body IO FM Episode 5) he did with AJ is the best source.
  • Dr. Patel has better blood sugars (gets back to normal faster on post carb days) when he uses non-fructose starches on his carb days.
    • The more processed higher fructose foods eaten, the quicker liver glycogen stores are replenished, and it’s the dumping of this liver glycogen on subsequent ultra low carb days will inhibit the advantages being sought in Carb Nite and Carb Back-Loading.
    • Ingested glucose has a hard time replenishing liver glycogen.  Glucose prefers to replenish intramuscular glycogen stores… and when these stores are replenished, it can’t be released into the blood to replenish blood levels.
    • Liver glycogen is supposed to be released into the blood so it is readily available.
    • Avoiding fructose is better for both Carb Nite and Carb-Backloading… but more so for Carb Back-Loading because it’s important to replenish muscle glycogen without replenishing liver glycogen
  • Some people have a hard time getting into ketosis, and the problem might be the glycerol flux (glycerol is one of the breakdown products when fat is broken down, and it can be resynthesized into glucose)


Came across a site that also wrote a review of Carb Back-Loading and does a fair job criticizing it.  Here are links to it: Part 1 and Part 2.

The author actually examines the original research papers that Kiefer references in his book and finds that there are quite a bit of inconsistencies with the conclusions Kiefer draws and what is actually written in the paper which actually happens more than you would expect academic research.

In fact while reading the The Perfect Health Diet I looked up one of the references that were used and found that it was incorrect.  If you’re interested you can read through the comment thread where I provided the link to the correct reference.

Perfect Health Diet Errata

Most of the time when people do this it’s on accident… but there are times when people do it with less than ideal intentions as well.

In any case, the posts are well worth a read through.

Despite the criticisms, there has been a lot of reported success with Carb Back-Loading which is why I’m still interested in experimenting with it.  Who knows, maybe it will be amazing for me, maybe it won’t change a damn thing, or maybe it might even make me worse.  All I know is that experimenting with it for 8-12 weeks is a small price to pay to find the answer!

If you’re interested in reading more about Carb Back-Loading, you can pick it up directly from his website here.

9 Responses to Carb Back-Loading Pearls and Criticism

  1. sootedninjas says:

    there are a lot of research on resistant starch. I think that he is a little bit bias because in conjunction with his protocol he does not know how it will affect CBL’s or CN’s results. That is the research he does not have. It’s perspective to Strength and conditioning.

    But when it comes to optimal health then resistant starch is a great protocol to use if you are metabolically healthy already. On just low carb my FBG is consistently in the high 90s to low 100’s BUT now my FBG straddles around the mid 85’s and the morning after a carb backload FBG in the low 90s’. As matter of fact there are days when I see my FBG mid to high 70’s.

    How do I know this. Well because I’ve been tracking my FBG and HRV EVERY DAY for the last 4 months.

    • BJJ Caveman says:

      Great that you’ve figured this out. That’s the beauty of n=1.

      I still plan on playing around with it… but don’t want it to interfere with my current experiment. After 8-12 weeks of carb back-loading, I may add in some resistant starch just to see what happens with my blood sugars and what not.

      Each time ‘HRV’ is mentioned… I get more and more curious….

      • sootedninjas says:

        optimal is the key. what is optimal for yourself. Because what works for me does not necessarily work for someone else. n=1 FTW !

        HRV helps you quantify your progress. Because the HEART does matter.

  2. sootedninjas says:

    Although, I have to say that CBL is NOT working for me as others have reported. However, I still do it as an excuse to cycle carbs into my diet. I’ve been doing low carb for a long time that it is so hard for me to eat carbs on a daily basis.

  3. NN says:

    BJJ Caveman,

    I have enjoyed reading your blog and have greatly benefited from it, especially in my efforts to tweak/design my own n=1 experiment.

    In this post, you mention that Kiefer prefers to see Carb Backloaders come out at 3 mmol/L ketones during the ULC portion of the day. How is that even possible when you have eaten a significant amount of carbs the night before (and all the nights prior to that)? My understanding (and personal experience) is that it takes at least a few days after a carb day/night to get back into nutritional ketosis, and possibly even longer if entering NK for the first time.

    What has your experience been?

    Also, once you are in NK, does it make a difference if you’re cruising at say 0.8 mmol/L vs. 3 mmol/L? Are you accessing fat reserves at a higher rate, or in some other way better equipped/positioned to burn fat at 3 mmol/L vs 0.8 mmol/L?


    • BJJ Caveman says:

      I have no clue how people are supposed to get 3 mmol/L ketones during ULC, especially after eating carbs the evening before. I don’t see how this is possible… at least with my own experience. Possibly if they trained super duper super duper hard and used up every last drop of intramuscular and intrahepatic glycogen… maybe this is only seen in uber elite athletes?

      As you can see in my Carb Nite experiments, it generally took me around 4 days to get back into ketosis… but this was without training hard. When I did train hard on Carb Nite, I could get back into ketosis in 2 days… but I’m obviously not an uber elite athlete.

      I don’t think there is enough data out there to indicate whether there is any benefit to having higher ketones. Various other n=1s that I’ve read report conflicting things, so this may be one of the ‘your mileage may vary’ sort of things. In my experience it didn’t really matter, but then again I wasn’t one of those folks that saw dramatic weight loss, and no matter what I tried, I couldn’t get my ketones to stay above 1.5 consistently.

  4. NN says:

    Thanks for the reply, BJJ.

  5. Bryan Evans says:

    Thank you for this post and your blog, I have really enjoyed reading your blog. I am experimenting with many of these same things, although I am not very good about documenting my experiences. I too was very surprised to see Kiefer mention 3.0 for ketones using carb back loading. I have been in ketosis for about 8 of the last 11 weeks. After about 2 weeks into it I bought my meter and my first reading was 7.1, I was shocked. I was doing what was really a ketosis/severe calorie restriction. In the first 2 weeks of having the meter I was always between 4 and 5. I took a 1 week departure back to lots of carbs and then went back to ketosis, but was eating more calories keeping net carbs around 30 and protein around 80 (a bit low) and spent 4 weeks between 1 and 3 on the ketones. I just started playing with carb back loading about a week ago, I have back loaded 4 times and haven’t seen ketones over 0.6 since then, the last couple of days have been 0.2.I admittedly have let my “fat kid” come out and play the first couple of back loads but I can not see how it would be possible to get anywhere near 3.0 the morning after back loading, based on my experience so far. I just thought I would share my thoughts.

    Thanks again for the post, I hadn’t seen this podcast, it had some good information.

    • BJJ Caveman says:

      Thanks for sharing. I too would be surprised.. and maybe a little alarmed with a ketone reading to 7.1, since that’s starting to get close to the ketoacidosis range.

      I’m also glad that I’m not the only one with an inner fat person that needs to come out every once in a while!

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