Advantage: This is a fully-individual, objective and reasonable-cost measurement.  The results cannot be argued with.  You either prove or disprove, for you, that this is true.  I do not claim that this is true for everyone, but for everyone I've had the pleasure of looking at this with it has been.  Nonetheless there are probably people for whom this does not apply; if you're one of them, after you test it yourself, then enjoy ignoring this advice because it almost-certainly does not apply to you personally.  But it does apply to nearly everyone in my experience, which means until you perform this test you must presume you're poisoning yourself daily.

Yes, I said poisoning yourself.  Slowly, but you are.

Every holiday season Garmin puts a number of their "smartwatches" on sale.  The key ones are found at this link; the bottom line is that anything that does overnight HRV is what you're looking for in the feature set.  The least-expensive as of this column is the Instinct 2 series.

There are others (e.g. the "Oura" ring) but note that one of the keys to this is not just overnight wear, but all-the-time wear.  This is a problem with many smartwatches and similar devices as they require frequent charging.  This is where Garmin excels; their devices will run a week or even two weeks between charges.  That matters because if the unit is not on your person it can't record anything and you need to wear it basically all the time for it to get an accurate baseline.

(BTW before you ask no, I don't work for Garmin and don't earn anything if you buy one -- I'm not a "referral affiliate."  I have been an avid user of their "smartwatch" and "exercise watch" (before the smartwatches showed up) products for roughly the last 15 years, and like their products a lot.)

After getting it you need to wear it essentially continually, especially overnight while sleeping, for about three weeks to establish a baseline.  During this time you should do what you usually do -- make no effort to change anything, because what you're looking for is the "as things are now" situation.

You can either download and use the "Connect" app on your phone (either IOS or Android) or connect the watch once a week or so to a computer and use Express, which is a small app that runs on your computer and will sync when its plugged in -- and of course your watch needs to charge too, so this is a good way to do both at once.  A web browser version of the Connect app is at https://connect.garmin.com and is essentially the same as the phone application, but in a larger format.

Once you have a baseline your graph will look like this (not the same values, but you'll have a "gray" area with green, orange and possible red markers) -- again, this will take about three weeks although the values will show up starting immediately.

If you click Overnight Averages you'll get both the rolling average (the dot) and the line, which will look like this:

Note that there is one night in that week that is out-of-range.

Now to test take a 24 hour period and make very sure you eat nothing that has a seed oil in it.  If you cook at home this isn't too tough, but it does mean not eating anything in a box or jar that has any mention of a plant-based oil (yes, including olive oil, palm oil and similar) on it.  Olive oil is likely actually ok but it is almost-always adulterated so for this purpose you must avoid it.  Essentially all salad dressings bought at the store are laced with this stuff as is essentially anything that comes in a box or other similar shelf-stable package.  If you eat eggs use either bacon grease, lard or butter (real butter, not reduced-fat or margarine) to cook them.  Meats and green vegetables, provided they are not cooked in or otherwise exposed to seed oils are perfectly ok as are hard cheeses (again, blocks of cheese, not processed stuff -- read the label!) and similar.  Spices are also unrestricted.

Leave everything else you do alone.

Note that one drink a day will hit your HRV overnight quite-reliably for a couple of points.  After 2 drinks in a given day it will get hammered, so for accurate results don't do that while performing this test.

Note the change, if any, in HRV over night.

If it goes up when you remove the seed oils you might want to keep doing that for a period of time until it levels off again.  This may take a bit, but once it does now you can "notch test" the hypothesis that they're harmful to you by eating something containing them and seeing if the HRV goes back down that night.

Notice that one night deviation?  That was from "buttered" crackers with a cheese dip (cheese I can eat in any amount without any impact at all and do regularly) but no other changes compared against my usual food intakes.  I know that's what caused it because this is a consistent hit whenever I eat seed oils and that day it was the only possible exposure to them at a pub -- which I did not expect because it was claimed the crackers were BUTTERED.  Obviously that was not butter; it just tasted like it.

Also note that this insult took two days to return back to "high normal" and in both of those days I consumed quite a bit of carbohydrates since it was, after all, Thanksgiving.  But -- all the food I consumed I cooked at home ex a gift scotch-infused "cake" that was imported and, on the label, were no seed oils (gee, fancy that; they don't use them in Europe in baked goods as a matter of routine!)

A week later I went back to the same place and ate the same baked wings -- but no dip and crackers.  The impact did not occur.  I thus know precisely what caused it.

If you get the same sort of result I do -- and yes, you should repeat it a couple of times because its always possible to accidentally confound a single test without realizing you did it, you have the gold standard of evidence for yourself because for any scientific experiment that standard is repeatability -- that is, every time you do something the outcome you first observed occurs -- not one time in three, not half the time, essentially or actually all the time.  It is only once you have established that you can make a claim for yourself but once you do then from that point forward if you continue to take in such substances voluntarily you are deliberately poisoning yourself and there is no escaping that fact.

If you get the results I get -- every time -- then you might go into a grocery store and pull off the shelf a can of infant formula.  Note what the third ingredient on the list (by law they must be listed in order of the amount present) typically is.

Incidentally if you've been eating this crap for a long time (and if you're most Americans, you have) it takes time for it to all leave your body because, being fat soluble, it winds up in all your tissues -- including especially your fat tissue.  Think of it like weed -- if you smoke some it will show up in your urine for a couple of weeks or more.  This is the same sort of thing, so if you get a positive result, that is, improvement, no matter how slight, if you're like most people and don't eat any of it the next day you will likely, for some period of time, continue to see improvement as it is eliminated from your body.

Until just a couple of years ago this sort of highly-sensitive and personal information was almost-impossible to obtain for the average Joe or Jane.  It wasn't impossible for researchers with effectively unlimited money to obtain these results but obviously nobody did the work or, if they did, they hid the results on purpose.

If you're one of the people for whom this damage does not accrue when you consume such things then happy for you.  But as I have noted, for virtually everyone, it is absolutely present and among those who have such devices and who have let me see them there it is.

This started with my observations with a still sensitive but less so metric (all day stress) where I'd bet others in the run club that I could identify which days they had consumed no alcohol in the evenings.  I won a lot of free beers this way.  All-day stress levels (which the Garmin watches also measure) is quite-useful but materially-less sensitive than overnight HRV and while you can read the seed oil impact in all day stress you have to pay a lot closer attention where with overnight HRV it literally screams at you.

Let me be clear: If you eat seed oils, at least in my observation, it is roughly equivalent on a metabolic basis to consuming THREE beers a day.  Nobody would consider a person who consumes THREE drinks a day, every day, to be "healthy"; any physician would tell you that this, if continued, is almost-certain to have very severe negative effects over time including alcoholism, liver failure AND ULTIMATELY DEATH.  Obviously if you drink on top of that then its even worse, and of course if you're drinking you're inclined to eat things, so there you go -- but after repeating this several times as an "isolation" (change one thing) test I can confirm that one item of food containing seed oils, all alone, does more damage than TWO beers.  This shit is in damn near everything, including virtually all commercially baked goods and anything that comes in a box.  It is basically impossible, for example, to consume any sort of salad dressing without eating this crap so stop kidding yourself about that salad being "healthy" -- the greens are probably fine but the dressing is not.

You can't even buy roasted nuts without them having this shit in them and it is extremely difficult to avoid them if eating out because they are not disclosed.  Even worse is putting them in foods that are served in places like schools where they're essentially force-fed to kids.

The worst "conspiracies", if you want to call them that, are those where multiple actors, all apparently unconnected, goad you into doing something and they all profit from it at your expense.  Seed oils are one of these: The food seller uses them and loves it because they're cheaper, the various "medical authorities" all told you to eat them in favor of animal fats (this was and remains an outright lie) and then when you did all the bad effects -- including obesity, diabetes and all sorts of inflammation-related diseases which seed oils cause as they are all inflammatory -- you have to come back and have treated.  Oh, and don't think you can get away from this by using olive oil -- it is extremely common for it to be adulterated with various seed oils and nobody ever goes to jail for that either.

We are headed for a train wreck across the health system of the United States.  The release of the "covid study" from Congress the other day, which claimed the shots "saved millions of lives" is a flat-out lie and not only that it is deliberately ignoring the enormous spike higher in cancers and cerebrovascular conditions -- heart attacks, strokes and clotting disorders -- that showed up exactly when the shots were rolled out and has not gone away.  In addition the last year has given us a two trillion dollar federal deficit which is all in CMS spending that is not offset with current tax receipts and that has been growing exponentially over the last three decades.  This cannot continue and if you are reliant on that spending you are going to be fucked.

I have been beating this drum for close to two decades now and in fact was raising Hell about it back in the 1990s, as it was obvious what was going to happen.  Rather than address it then when it was reasonable we instead doubled down and kept doing stupid things, including both lying to others (by physicians, so-called "public health" experts and others) and ourselves in what we stuff into our mouths.  But now, rather than conjecture and association, which can provide strong evidence when its is across huge populations but cannot, as an association, be conclusive we have available at little cost the capacity to determine at an individual, personal level whether these issues apply to you individually in an actual test you can perform, nobody else has access to and which is irrefutable evidence that your specific metabolism is poisoned by consuming these things.

We should hang every so-called "health official" and "doctor" who advises you to consume this crap, all the way back to infant formula.  We should force black-box labels on every food and container of such material in every store and absolutely ban them from any place where they are not disclosed and thus avoidable (e.g. restaurants should have to label every item on their menus that contain same.)

But this journey, in fact, begins with you proving to yourself that these people have conned you into poisoning yourself on a slow but relentless basis since your infancy and then, once you have satisfied yourself that this is in fact the case for you then what you choose to do next -- whether it simply be avoiding all such consumption for your person or taking it on more-broadly is up to you.  I will not advocate violence but I will certainly understand if you decide that it is warranted, exactly as many have publicly expressed quite-recently.  All these people -- the FDA, NIH, physicians, insurance firms and pharmaceutical companies had to know; this crap has been going on as a concerted advocacy message and in fact when it comes to schools and such has been forced on our kids for decades, never mind the most-blatant example being that every hospital sends every new mother home with a box of formula full of this crap knowing full well that if she uses it her lactation will dry up from non-use and both she and her infant will be effectively compelled to continue to buy and consume it.

But from that point forward, even if all you do is stop eating that which screws you on a personal basis, you'll start to become more healthy literally by the day.

PS: Note that this has no impact on, nor is targeting high-glycemic consumption which is known to produce insulin resistance leading to obesity and Type II diabetes (nor does it account for statins which have an actual label warning that they cause diabetes -- which, of course, your doctor will push on you after you create systemic inflammation via consumption of seed oils and cholesterol is part of the body's repair mechanism so increasing inflammation will cause the liver to make more of it!)  This is targeting only seed oils -- but if you're not going to change anything else, and many people simply won't, for the love of all that is Holy change this.

And by the way, contemplate this -- ninety percent of comments on the recently-whacked health insurance CEO were not expressing horror or disgust (at his murder); they were somewhere between "well, bye Felicia!" and outright glee.  To those of you in the medical, pharmaceutical, "so-called healthy oil advocacy" groups and food producers -- once people figure this one out, and they can with absolute finality for any individual person -- exactly how many people are going to get really angry, especially when they walk down the grocery store aisle and note what the third ingredient is on essentially every can or bottle of infant formula?