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What is Metabolic Health?

America is in a metabolic crisis as only 12% are “metabolically healthy” (r), but what does that mean? Here I’ll compare my biometrics to the proposed standards of metabolic health.

First, let’s point out the obvious. Metabolic un-health, or metabolic syndrome, is a major contributing factor to an array of premature causes of death, including susceptibility to COVID-19 (r, r). Obesity, in particular, has been identified as a pandemic since at least 2004 (r, r).

So, let’s look at these metabolic health markers (r, r, r) and then we’ll compare my own biometrics.

  • Cholesterol: HDL > 40, Triglyceriees < 100
  • Waist Circumference (WC): 102/88 cm for men/women
  • Fasting Blood Glucose: < 100 mg/dl
  • HBA1c: < 5.7%
  • High Blood Pressure: 120 / 80 (mmhg). This is the most common figure for “normal blood pressure”, but the diagnostic criteria for metabolic syondrome can be higher, such as 130 / 85 or 140 / 90 (e.g. hypertensive rather than “above normal”).

Cholesterol (HDL):

Goal: > 40

Current: 67 (Feb. 2020)

Discussion:

This is the “good cholesterol”. If you think of your blood vessels as a highway, HDL is kind of like the street sweepers that keep things cleaned up or the police directing traffic (r). In Feb. 2019 my HDL was 89 and I was on a paleo-ish keto diet. At my most recent screening (2020), I had been on a carnivore diet for 2 weeks, which I don’t think is significant. However, I’m well above the recommendation for HDL! So, I haven’t gotten around to another blood lipid test. To set the record straight on LDL, check out Dave Feldman’s work (r, r).

Things like olive oil, fatty fish (rich in Omega 3 fatty acid), and saturated fat (red meat, dairy, coconut oil) can raise HDL (r, r, r). A quick note on Omega 3’s is that they need to come from animal sources (EPA / DHA) in order to be bioavialable. The AHA form found in plants (like flax) must be converted to EPA or DHA to be used by the body and the conversion rate is extremely low, amid other vastly negative effects of PUFAs (r, r, r).

Cholesterol (Triglycerides):

Goal: < 100

Current: 99 (Feb. 2020)

Discussion:

Triglycerides are the reckless drivers causing crashes in the highway of our blood stream. They also harden and thicken our artery walls (r). Notice too that the metabolic health standards don’t mention LDL, commonly referred to as “bad cholesterol.” This is a misnomer as it’s quite necessary. Again, I highly suggest looking at Dave Feldman’s work (r, r).

If you’re following along, a triglyceride to HDL ratio would ideally be 2:1 (though many achieve 1:1), but it’s commonly considered “good” at 4:1 (Kevin Stock)(r).

The largest contributors to elevated triglycerides are obesity and diabetes (see waist circumference and blood sugar below), but there appears to be conflicting research on the effects of coffee on triglycerides – something I’ll look into in the future (r, r, r).

Waist Circumference:

Goal: < 102 cm

Current: 76.2 cm (Feb. 2020)

Discussion:

This is a pretty lazy (and lousy) metric in my opinion, for the same reasons that BMI is lazy and inaccurate. BMI, specifically, tends to over estimate fatness (level of unhealth) in muscular people (with more mass) and under estimate the fatness of people with less mass, leading to the “skinny-fat” syndrome where a person is at a “healthy” weight, but over fat (r, r).

Further, a very obese person and a body builder might both have a BMI of 40. They both might also have a similar waist circumference, but obviously have different levels of metabolic health.

A much better measure that I’d substitute for my own interests would be percent body fat (PBF). The leanest 5% of Americans would be < 28% for women and < 17% for men (r), or to keep it simple, < 30% for women and < 20% for men. For athletes though, 20% / 12% is not unreasonable either (r). Essential body fat is about 15% / 5% (r) for women / men.

Blood Sugar (Glucose):

Goal: < 100 (fasted)

Current: 90-100 (May 2020)

Discussion:

The above recommendation is for a fasted blood sugar (> 9 hours, but ideally more than 12). Recommendations for 1-2 hours after a meal are 140 - 180 mg/dl (r, r). However, I’d lean heavily towards the former because your blood sugar jumping from 80 or 90 all the way to 180 after a single meal is a serious spike and suggests you’re consuming way too much sugar in that meal (processed, whole grain, or otherwise). Stabilizing (minimizing large spikes) in blood sugars is extremely important for managing mood, hunger, and hormones (r). In fact, if you could restrict your postprandial blood sugar to < 120 (a spike of 20-30 mg/dl) that would be even better (r)!

A few other quick notes here:

  • Caffeine doesn’t appear to effect blood sugar (r, r).
  • Sugar Alcohol (in many sugar free products like gum) does raise blood sugar (r). Insoluble fiber has 0 net carbs, sugar has all the carbs, and sugar alcohol has 1/2 net carbs (r). Sugar alcohol can also cause diarrhea (yes for me), is addictive (yes for me), and different alcohols have different glycemic loads (r).
  • Low Body Fat: would probably help all of these categories (see waist circumference above), but has also been shown to improve insulin resistance (r), though in an episode of The Healthy Rebellion Radio (r) Robb Wolf talked about a point of diminishing returns when it comes to reducing body fat; e.g. at some point being “too lean” is a stress on the body (see essential body fat above).

HbA1c (Hemoglobin):

Goal: < 5.7%

Current: ~5 - 5.5%

Discussion:

Hemoglobin directly relates to blood sugar, so I won’t say much more on that. I don’t have this tested regularly, but again it’s relative to blood sugar which is easy and affordable to check (via finger stick, though a CGM / Continuous Glucose Monitor wouldn’t be a bad idea).

Blood Pressure:

Goal: < 130 / 85 (ideally 102 / 80)

Current: 140 / 80 (typically)

Discussion:

Ah, the boon of my quest for metabolic health, or is it? This is the one thing I’ve had the most difficulty nailing down and will definitely write more on in the future.

Common advice is to lower salt intake, but if you’ve read The Salt Fix or my previous article on sodium and blood pressure, then you’ll know that this isn’t necessarily true; and in fact you may be doing far more harm than good by dramatically decreasing your sodium – especially if you are a athlete or are on a low carb diet and especially if you’re both!

Other recommendations often include magnesium (r), potassium or sodium to potassium ratio (r), and reducing caffeine (r); all of which were ineffective at reducing my blood pressure in my testing.

Stress can also effect blood pressure and so can obesity (see all of the above factors). Something else worth mentioning here that melds well with the pro-salt argument; is cardiovascular load (CVL). CVL is measured by MAP * RHR (resting heart rate). MAP = ((systolic BP + diastolic BP + diastolic BP) / 3). Diastolic BP (the bottom number) counts twice because it is the pressure when your heart is relaxed.

The take home point here is that something like lowering your salt intake might have a marginal effect on lowering your blood pressure, but raise your heart rate (among other things) and neutralize the overall benefit to CVL. For example a BP of 120 / 80 gives us a MAP of 93.33. An “average heart rate” is between 60 and 100 bpm (r), so let’s say it’s 70. That’s a CVL of about 6500 (93.33 * 70). If my blood pressure is 140 / 80 (MAP = 100) and my pulse is 55, that’s a CVL of 5500, far below what’s considered “normal.” Though it’s a much different story if you’re looking at blood pressure in isolation.

Conclusion:

In general, gut health, insulin sensitivity, body fat, cardiovascular health, impact significant factors in our life ranging from immune function and quality of life to mortality and mental health.

Let me know in the comments if there are any of these specific qualifications that you want explored in the future or have questions about. I’ve linked several of the previous self-studies I’ve done and there will be more follow up specifically regarding blood pressure.

This post is licensed under CC BY 4.0 by the author.