Aug 31

Lab Tests – Measuring your Metabolic Health

Note from Craig–

In addition to helping Dave wrangle data behind the scenes, I will occasionally be dropping in as a guest writer to contribute some additional content. This blog was an invaluable resource when I first found out I was a hyper-responder, and I’m looking forward to helping others understand their own cholesterol situations. Hope you enjoy!


I started on Keto five months ago as an experiment in endurance running. Tall and slim, I’d get funny looks whenever someone heard I was on a diet. But, if they didn’t have to eat it, nobody cared much about what was on my plate.  Then, the cholesterol bugaboo appeared.

Total Cholesterol 358
Triglycerides 66
HDL-C 114
LDL-C 231

(Frequent readers may find this pattern familiar.)

Suddenly, everyone was “concerned about my cholesterol” – my doctor, my mom, distant relatives. I wasn’t worried during the test, since I heard it was possible to manipulate, but the seed of doubt had been planted. I now needed a lot more evidence to prove to myself, and others, that I wasn’t doing myself harm with this experiment.

I redoubled my efforts reading and watching everything I can find on the links between diet, health, disease. I was especially worried about heart disease (what they say might kill me), and metabolic syndrome (what I think is most likely to kill them). Fortunately, a certain N=1 pioneer had already made a lot of progress on this path, and he was generous with his advice.

This article is one software engineer’s opinion on what blood tests are worth your while when you get your annual poke in the arm. These tests will provide the necessary feedback for those interested in “debugging” and “optimizing” the complex system that is their body.

If you can’t measure it, you can’t improve it. 

– Peter Drucker.

Asking for Tests

Ideally, you want your doctor to order the tests you’re seeking so that your insurance pays for it. But different doctors can have different reactions to these requests. Some will happily rubber-stamp your request without question, others will ask why you are interested in these tests and how you found out about them in the first place. If you find your doctor won’t order the tests you’re asking for, you can usually order them privately through a service like http://RequestATest.com.

If find yourself needing to explain ‘why’, here are some arguments that your doctor might find persuasive.

You will use this data to make informed decisions about your lifestyle.

“I am actively tracking my food, sleep, stress, and exercise and I want to know how my body is doing. Even though I feel much better on my diet, I’d consider changing if there was good evidence something was going wrong.”

You want to establish a broad baseline of health and disease risk.

“I’m concerned that conventional diets contribute to obesity and disease. I choose my diet to help with that, and I want to see if I’m making progress across the board. Then, I can tell if future changes help or hurt.”

Your body uses a higher percentage of energy from fat compared to typical diets.

“There’s a good reason that my numbers might be unusual. I want to see if my body is working well, but differently, or if something is going wrong. I also want to be careful when considering treatments, since they are rarely tested on people with my diet.”

Treating complications later is much more costly than testing now.

“A diabetes diagnosis more than doubles your average lifetime medical expenses, while a heart bypass surgery is over $100,000. I want to accurately assess my risk now, so I can take action to improve my chances of avoiding these outcomes.”

The Tests

Every time:

  • Insulin
  • Hemoglobin A1c
  • C-Reactive Protein (High Sensitivity, Cardiac)
  • Comprehensive Metabolic Panel (14)

Tracking your lipids:

  • NMR Lipoprofile (Nuclear Magnetic Resonance)
  • and/or Apolipoprotein A1, B

Tracking your risk of metabolic syndrome:

  • GGT
  • Ferritin, Serum
  • Uric Acid, Serum
  • Homocyst(E)Ine, Plasma

Tracking your general health:

  • Vitamin D, 25-Hydroxy
  • Cortisol
  • Cbc With Differential
  • Iron And Tibc-Iron Binding Capacity (TIBC)

Only once if normal:

  • Apolipoprotein Lp (a)
  • Thyroid Panel

Apolipoprotein A-1, B

Apo A-1 is the distinctive protein of HDL. Apo B is the distinctive protein of VLDL, IDL, LDL and Chylomicrons.

Measures the composition of your lipoproteins (the mass of the apolipoprotein), unlike cholesterol tests, which only measure their contents.  The lipoprotein particle tests are much better correlated with outcomes than cholesterol, but those two metrics are often discordant on a low-carb diet. I’d certainly want to have both results before making any decisions about “my cholesterol”.

$49 at RequestATest

Apolipoprotein Lp (a)

Apo (a) is the distinctive protein of lipoprotein(a), a subclass of LDL.

Lp(a) appears to be an independent risk factor for CVD beyond other blood lipid markers. It is largely determined by genetics, so testing it at least once will inform the importance of other more readily available LDL numbers. This result could raise the stakes of any lifestyle tradeoff you make.

$49 at RequestATest

Cbc With Differential

Measures the composition of your red and white blood cells.

Red blood cells deliver oxygen for burning. White blood cells are part of the immune system that protects your body from infection. This test helps give a broad picture of your health.

$29 at RequestATest

Comprehensive Metabolic Panel (14)

Measures various minerals and nutrients (including electrolytes) involved in your body’s processes.

This is a common test used to screen for a variety of conditions and nutrient deficiencies. This panel comes in (8) and (14), so be sure you specify the number.  This test helps give a broad picture of your health.  You can also use it to tweak your nutrition, for example, adding more salt if sodium is low.

$29 at RequestATest


Cortisol is a steroid hormone that your body releases in response to stress.

Chronic stress is extremely taxing on the body and can contribute to pain, hunger signaling, and heart disease.  Measuring your stress allows you to judge the effectiveness of your stress-reducing efforts, like exercise and sleep.

$45 at RequestATest

C-Reactive Protein (High Sensitivity, Cardiac)

CRP is a protein produced by your liver as part of the inflammatory response.

Inflammation is a process your body uses to fight foreign invaders. Appropriate when you scrape your knee, but problematic when prolonged. High CRP can be a warning sign that your body is reacting to something in your diet (gluten or vegetable oils) or body (damaged arteries).

$59 at RequestATest

Ferritin, Serum

Ferritin is a protein that stores Iron.

Elevated ferritin can be an indicator of high iron or metabolic syndrome. Recent research suggests that it may even play a causal role in CVD.  You can also mitigate high ferritin with regular blood donations. This test helps give a score in your struggle against metabolic syndrome.

$29 at RequestATest


γ-Glutamyl Transferase is an enzyme found in many parts of the body.

Elevated GGT is a diagnostic marker for diseases of the liver and pancreas. This test helps give a score in your struggle against metabolic syndrome.

$29 at RequestATest

Hemoglobin A1c

Hemoglobin A1c measures the glycation of your red blood cells and is a used to diagnosis diabetes.

Glycation is when blood sugars stick to a protein or lipid in your body, causing trouble. HA1c is an approximation of your average blood glucose of the past 3-months. This test helps give a score in your struggle against metabolic syndrome. Amy Berger’s low-carb testing series covers HA1c in detail.

$29 at RequestATest

Homocyst(E)Ine, Plasma

Homocysteine is a non-protein α-amino acid.

Homocysteine in the blood can make you more vulnerable to endothelial damage, so it’s a risk factor for CVD. These results could raise the stakes of any lifestyle tradeoff you make.

$69 at RequestATest


Insulin is a control hormone that regulates the metabolism and storage of nutrients.

Elevated Insulin is part of the vicious cycle of metabolic syndrome. Although not as informative as a full Kraft Test (multiple insulin measurements tracking the response to glucose intake), fasting insulin provides a much better snapshot than glucose or HbA1c.  With the prevalence of diabetes in society today, it’s a wonder this test is not standard. Amy Berger’s a low-carb testing series covers Insulin in detail.

$49 at RequestATest

Iron And Tibc-Iron Binding Capacity (TIBC)

Iron is an essential nutrient used to produce red blood cells.

This test measures your levels of iron and proteins that transport iron. This test helps give a broad picture of your health.

$29 at RequestATest

NMR Lipoprofile (Nuclear Magnetic Resonance)

The NMR lipoprofile measures the number and size of your lipoproteins.

Not all lipoproteins are created equal, and those on a low carb diet often have much more favorable size distributions.  This gives the most detailed snapshot of your lipid system is working.

$99 at RequestATest

Thyroid Panel

The thyroid gland regulates energy use in your body in a multi-step process. This panel measures the levels associated with each step of that process.

How well your body metabolizes nutrients affects energy levels, heart rate, weight regulation, and temperature.  This test helps give a broad picture of your health. Amy Berger’s a low-carb testing series covers Thyroid in detail.

$49 at RequestATest

Uric Acid, Serum

Uric acid is an end product of purine breakdown and is found in urine.

Excess uric acid levels can cause gout and kidney stones. Your levels are affected by diet and kidney function, but also may be an independent risk factor for diabetes. This test helps give a score in your struggle against metabolic syndrome.

$29 at RequestATest

Vitamin B12 And Folate

Vitamin B12 is an essential vitamin used for making red blood cells and DNA.

Excellent B12 levels should be a expected on a diet rich in animal products. This test helps give a broad picture of your health.

$69 at Requestatest

Vitamin D, 25-Hydroxy

Vitamin D is a fat soluble vitamin needed for mineral absorption (calcium, magnesium, phosphate, zinc) and metabolic function.

Your body converts cholesterol to Vitamin D in the skin when exposed to sunlight. However, since we get much less sun exposure today, it often requires active supplementation to achieve adequate levels.

$59 at RequestATest


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  1. BobM

    They say Lp(a) is genetic, but mine has decreased by about 28% in 3 years, and this also seems to go up for long fasts.

    1. Craig


      By genetic, I mean there are some people that have little or no Lp(a). For those that do have some, it seems very likely that it could be just as dynamic as the other apolipoprotiens.


  2. Bonnie

    Thank you for this list! I had very similar lipid results last spring and my GP was adamant I should take Statins. Of course I would not take such a controversial drug without a lot of research on my part. I am a fit, active 64 year old female. When I asked my GP for access to CAC and further bloodwork, she looked at me and said she was not familiar with the tests, would not be comfortable ordering them and referred me to a cardiologist. That was 3 months ago. I went ahead and paid for a CAC (750 dollars later, score 80) and now, armed with suggestions from your list, I’m heading to Seattle to get bloodwork done there and pay privately.
    Since May I have faithfully followed a ketogenic diet with carbs less than 20 and mod. Protein. About 75-80% of my diet are fats (following Dietdoctor and other sites, like this one on what would be healthy fats).
    Now I am curious to see what the bloodwork shows. Some tests I can easily get through GP so these are the ones I am ordering from online lab –
    C Reactive Protein
    NMR Lipoprofile
    Apoliproprotein A-1,B
    Apoliprotein Lp (a)
    Hemoglobin A1C

    I’ve had annual bloodwork done for years as I have been diagnosed hypertensive since early nineties. (CBC, electrolytes, thyroid, common blood work always normal). My BP is well controlled (thinking I might be able to get off meds for that as BP is lowering and I’m tracking daily results. GP does not see the need for HgB A1C as my fasting blood glucose has never been high. Do you think I should bother with the HgB A1C?

    I’m quite distressed about the CAC score – doesn’t seem fair given I have always been active and other indicators always suggested I am healthy. To know that 75% of women my age have lower CAC scores is distressing. I do seem to have a pretty strong family history of heart disease but they all smoked or were subject to 2nd hand smoke. I wish I had known about CAC tests before now as I would have certainly had one done years ago.

    The more I learn about conventional dietary guidelines, big Pharma, big Food industry, AHA and our Canadian Heart Association being sponsored by questionable donors, the more angry I get. And frustrated, impatient with physicians who know sooooo little about nutrition and current research on CVD but still have no qualms perscribinh heavey duty drugs. My GP never once asked about lifestyle, my diet, excercise – just wrote out the script! Ok, I’ll stop ranting but my way of the future is to take control of my own health and learn as much as I can, and continue my own N=1 experimente Thanks again! Great site. I will support this site with monthly contribution and encourage others to do so as well. Great service so freely given.

    1. C

      Hi Bonnie,
      Methinks you were ripped off with the CAC test….. in my neck of the woods it is $99 self-pay!

      BTW, here is an interesting site that estimates your arterial age based upon your CAC score: https://www.mesa-nhlbi.org/Calcium/ArterialAge.aspx

      Unfortunate, I am mostly in the same boat as you with the ignorance of doctors. My doctor never heard of most of these tests either… but I was lucky enough that he had heard of a CAC scan and was willing to write me a prescription for one. For most of the blood tests, I use RequestATest.

      In my layperson opinion, you should definitely get a Hb A1C test and also a fasting insulin test periodically. You can get A1C self-test kits on Amazon for about $40 for two of them. Since A1C changes very slowly (~3 months due to average life span of red blood cells), it is not necessary to take it all the time. But it is a general marker of your metabolic health.

      I also do a fasting insulin periodically, because metabolic problems will show up there before they show up in the A1C. RequestATest also offers that one. Another good insulin test is the Kraft insulin assay, but I haven’t done this test since my fasting insulin is very low. It measures the insulin response to a glucose stimulus over several hours. You can get it here: http://meridianvalleylab.com/Kraft-Prediabetes-Profile

      1. Craig

        The Kraft insulin assay test is amazing, but requires multiple samples over a 4-hour window. However, a single sample at the 2-hour mark is a decent approximation. With a bit of timing, you can do that yourself with a single test at your lab.

        Check out the insulin response graphs based on Kraft’s work at look at the 2-hour mark:

  3. Craig


    Glad to be of help! Thanks for your support!

    For the NMR and A-1,B tests – if the NMR is available in Seattle that should be enough. The A-1, B tests are mostly a way to get particle counts if NMR where isn’t available (some countries / regions).

    HA1c is much more valuable than fasting glucose. For example, if you have big glucose swings from carby food, that will show up in a way that fasting glucose doesn’t. Or not enough sleep, or stress, or any other reason for chronically elevated glucose.

    It sounds like you only switched to Keto a few months ago. CAC 80 is more a measure of the 60 years of conventional dieting. I wouldn’t be too discouraged, I think you are likely doing yourself a world of good! Dave had a really good analogy for plaque and calcium. It’s your body’s way of spackling the wear in your arteries from prior damage. You’d much rather have the spackle than a hole! Stable (or very slighly growing) CAC is a sign that there isn’t much additional damage happening. See if you can get a test for ~$100-200 next time and test again in a year or two.

    You’re preaching to the choir on traditional guidelines. The best we can do is educate our friends and family to slowly make a difference.


  4. Bonnie

    Thank you for the feedback. That will save me a few dollars. One more question, if I get an A1C done, should I also get a fasting insulin? Or is that redundant?


    1. Craig

      Absolutely get both. A1C relates to your average blood glucose. Insulin relates to how hard your body is working to maintain those levels.

      1. Bonnie

        Well, this doesn’t look good.
        LDL HDL. TRIG. T.CHOL.
        2012 4.9(189.5) 2.0(77) 1.3(115) 7.5(290)
        2013. 6.3(244) 2.2(85) 0.5(44). 8.7(336)
        2014 5.5(213). 2.0(77) 1.08(96) 8.3(321)
        April 2017 7.5(290) 1.98(76) 1.72(152) 10.3(398)

        As noted above in my last message, I did a calcium scan and got a score of 80. Over the last 4 months, I have been faithfully Ketogenic with less than 20-24 carbs a day, most days less than 20. I’ve lost 12 lbs (although not my primary goal – feels great and I’m now more in line with my adult weight over decades)

        BUT – then I travelled to Seattle for a Cardiac Panel and now see my LDL is increased! The LDL results looks Scarey! WHAT CAN I DO NOW?? I have so many questions but it seems clear to me (intuitively anyway) that such a fast rise in LDL cannot be good. That doesn’t sound like homeostasis or being in balance. What is wrong and how do I fix it?

        Cardiac Lipid Panel from Requestatest Aug 2017
        LDL-P 3492 (>2000 Very High)
        LDL-C. 383. (>189 Very. High)
        HDL-C. 85
        TRIG. 88
        T.Chol. 486

        LDL and HDL Particles: HDL-P (total) 36.5
        Small LDL-P 374.
        LDL Size 22

        Insulin Resistance LP-IR <25 and <45
        (I don't really understand this test but it seems I am low risk – i think these numbers represent percentiles)

        HgB A1C 5.4

        Lipoprotein (a) 5 (How do genetic factors influence this?)

        C-reactive Protein, Cardiac 2.39 (average relative risk for CHD is 1.00-3.00)

        Homocysteine 11.0 (average)

        One comment on the lab results "small LDL-P and LDL size are associated with CVD risk, but not after LDL-P is taken into account" took away my satisfaction with my particle concentration and size.

        I don't know what to do. Maybe I should just quit eating

  5. Amy Paulshock


    How do I jump on this bandwagon? I’ve also responded poorly, cholesterol-marker-wise, to low-carb/keto diets, and need help figuring out what to do about it. My latest particle count is 2152. My HDL is 132, which I now understand is NOT good. I am insulin resistant and was overweight until I went on this diet about 10 years ago. (no longer :o) Even now my A1c hovers around 5.6- 5.7.

    So the icing on the cake is, I have parkinson’s disease and want very badly to be able to stay in ketosis–studies suggest it might be neuroprotective. (And, interestingly, my neurologist said: “Hmm. Your symptoms seem to be worsening very slowly. Huh. Excellent.) (Of course, I am a study of one, so I get it–it means nothing.)

    And of course it doesn’t help if I drop dead of heart attack. Anyone have any ideas?

    Thanks in advance!

    1. Craig


      It sounds like you are doing great now! Low-carb has helped: Insulin sensitivity, weight, A1C, parkinson’s.
      How do you jump on the bandwagon? If I were you, I’d KCKO (Keep Calm, Keto On) and read up on some of the excellent journalism and books that have pretty much debunked the lipid-heart hypothesis for additional peace of mind. (Big Fat Surprise, Good Calories Bad Calories)

      There is a huge difference between a biomarker being associated with worse outcomes in one study and it being shown to be causal. It’s like saying “People 50x more likely to die in an ambulance than in their home — Let’s junk all the ambulances to save lives”. Or, if “People who were 5′ tall live 20% longer than those that are 6′ tall — Let’s cut off the feeet of tall people to improve their longevity”.

      In your case, your lipoprotiens are exactly doing their job, delivering fat energy to your cells. I’d be totally happy to have HDL of 132 (I’m around 115) and LDL-P of 2100 (I’m was 1600 last checked, but probably am higher normally).

      Another huge piece of mind for CVD risk is to get a CAC score. You can sometimes get that for $99 out of pocket, and it’s a much better predictor than any other single test.


  6. Amy Paulshock

    Thanks for your quick reply!

    My understanding is that (sadly) the latest info on HDL is that anything over 100 might be, paradoxically, a bad thing. (Who’da thunk it!)

    I know, I know, read those books, and Peter Attia and Thomas Dayspring et al. and I’m not convinced I’m gonna die tomorrow, but I’m not convinced I’m not, either. I guess I’d feel better if I could get my LDL P down to 1600 or so…hedge my bets. I also have some inflammation markers, high Lp-PLA2, Lp(a)-P. And yes I want to get a CAC score! Excellent idea!

    I am keto-ing on, but being a bit frantic about it: cut out the MCT and most of the cream and butter. Keto is VERY VERY hard with only olive and avocado oil. And no MCT to cancel out the occasional raspberry! :o(

    – amy

    1. Colleen

      Amy: I believe from other reading that the MCT is a different structure saturated fat than the dairy, such that you may be able to keep MCT even if you are cutting out diary.

    2. Craig


      What are your numbers for inflammation? Those usually go down on a low-carb diet. That’s something I’d watch and look for it to be going down. Are you watching your omega-6 PUFAs? Some people also have intolerances to eggs, dairy, or certain nuts.

      There is a lot of noise and confusion with HDL, particles about what’s “good” and “bad”. Sadly, much of it is misinformed or exaggerated. Maybe high particles are the real danger (I think not), but atherosclerosis is a slow process that takes years, even with the worst lifestyle. What’s awesome is we know the right metrics to test to see if its getting progressing or holding stable (inflammation, CAC). You have the time and the power to do an experiment to see how keto is working for you!

      You could try embracing the butter, cream, coconuts, and associated particles of keto and then check your metrics again in a year. Use that year to read up and observe how you feel. That’s essentially my strategy.

  7. Colleen

    Craig or others:

    Any thoughts on Quest vs Labcorp? I had a sky high ferritin test with one and shortly thereafter, the other normal (basically an impossible result if both were accurate). I am thinking about rerunning a ferritin at both on the same day. Any thoughts on the cholesterol and other test kits online from Amazon?

    1. Richard Maurer

      Ferritin does bounce around – inflammatory reactions, especially infectious etiology, result in elevated serum ferritin. This helps drive the acute inflammatory response to eradicate the infection. Whenever I see an elevated ferritin, I run a repeat # a couple months later.

      Labcorp and Quest in the US are very comparable -Practically, I would consider the results apples to apples. – note that even the same blood sample at the same lab can be up or down up to 5% (I have seen up to 10% on several tests) on repeat tests the same day.

  8. Amy Paulshock

    I wondered about the MCT! I cut out straight coconut oil, but continued w/MCT until recently. Maybe I’ll go back to it. It does help.

    I try to avoid omega 6 PUFA’s (I mean, OK, we do eat Duke’s mayo once in a while, yes) but I take a teaspoon of ultimate omega 3 every day and eat a fair amt of fish. And yes my meats and dairy are grass fed blah blah I know the drill! :o)

    You know, I wish I had my own lab! I’d love to tweak my diet–test my blood….tweak again–test again. Because the whole: try butter, go off butter…try MUFA…try plantain… etc…it’s hard to know what’s working best when you can really only test once a year or so.That’s a long time.

    But Craig you brought up the best idea. I am going to get a CAC. I think that will put my mind at ease. Or not.

  9. Jordan

    I’ve been fairly strict keto for 1.5 years. Like Dave I’m fairly lean (7-8% BF) and muscular. Had a few cholesterol/blood draws in that time and my cholesterol is high but not as high as some folks here, but I’m not absolutely worried about it at the moment. One thing I am worried about is my inflammation markers. Of the 4 measured (CRP, Fibrinogen, Lp-PLA2 and Myeloperoxidase), all were within optimal range expect Lp-PLA2, which everytime I’ve measured has been greater than detection limit (>600 ng/mL). I’ve never done the cholesterol drop test to see if this changes with dietary fat. Is anyone familiar with this test and know where I can learn more about it? Anyone else have similar experience? I’m happy to include more numbers if that helps.

    1. Craig

      There is the basic info at RequestATest.

      Lipoproteins are multi-use (primarily TG delivery), so a high marker associated with them (Lp-a or Lp-PLA2) doesn’t mean inflammation was the cause. Especially, if CRP is low eating LCHF, as it is in your case.

      In general, inflammation is a response to make your body inhospitable to outside invaders. If it is chronically high, it either means your body is constantly overreacting, or there is some persistent aspect in your environment that is perceived as an invader.

      We’re always happy to collect more data. I can email you privately if you’d prefer to keep them anonymous.

      Did you get the high-sensitivity version of CRP?


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