New Keto Term: "Phinney" Weight


Not insisting that others share my belief, but I just feel like in these types of forums it’s easy to make BMI a whipping boy. Many people come to the keto diet looking for a way to lose excess weight, and I think it does those people a disservice to say that BMI is useless. And it’s relevant to this thread because I can see this Phinney weight thing having the potential to trend the same direction.

(G. Andrew Duthie) #40

Well, people say that BMI is useless because it is useless…for diagnosing individuals. When both the creator of the original statistical model and the person who coined the term BMI say that it isn’t appropriate for diagnosing individuals, perhaps we should listen to them. There are FAR better tools for those for whom weight loss is a primary goal to use to gauge progress.

I’m sorry that you think that “Phinney weight” is doing anyone a disservice. I think it’s a fun and light-hearted way of taking ourselves a bit less seriously. Seems like most folks like the idea…but not everyone has to agree.


Unfortunately, lots gets lost in translation. BMI metrics can provide insight such as trends over a long period of time. Engineers call it R&R Gage analysis. If someone consistently uses a tool or method consistently, and it is done many many many times over a long period of time, the “drift” of the measurement will tell you something (is it trending higher, or lower, or plateauing, etc). However, you cannot take the average of all those measurements, nor can you take a single measurement, with confidence.

So, with BMI…we see the trends of certain States in the USA increasing faster than others. This sort of info gives a bit of insight as to what is going on. But, unfortunately, the granularity of that composite map of millions of measurements is impossible to dis aggregate and re-bundle into a single data point or target.


Sorry, Kirkor. This is the point where I put my engineer hat on and deep dive into scientific methodologies.

Check out the following diagram:

Like I said before, engineers use R&R Gage analysis to figure out how reliable the measurement system is. It is possible that the measurement system has many flaws, but, it is still used because the “drift” over time can still tell you something (i.e. is BMI increasing in the USA or not?), even though it is useless to use for a single point of data.

Math is beautiful…ain’t it? :stuck_out_tongue_winking_eye:


@Fiorella I don’t think I’ve ever said that BMI is accurate or precise. I’m claiming that it is useful.

Some photos: Flickr album


Again, I’m not convinced. The human eye is easily tricked. Same BMI of two people can easily mislead the eye, and give different conclusions…and not just with athletes.

Where BMI is useful is a very large data set, that trends over time. Ergo, where the composite BMI of the individual states in the US…showing which are increasing and at what rate.

I’d be very careful with using measuring systems that, like you say, are not accurate and not precise, to sway people down the wrong path.

If BMI was accurate and precise for individuals, every pair of jeans would fit the body…as you know…MANY different cuts of jeans in the SAME size are needed for the range of body morphologies.


Only if you are looking for them. I think part of Phinney’s point is to not get all judgey about it. You find the balance that is right for you. If someone else looks at you and says you have used some loophole because you are still not skinny - FUCK THEM!

(Dustin Cade) #46

my issue with BMI is that it is used to gauge an individuals health, like a certain number means healthy or not healthy… its a simple tool to get a rudimentary idea of where a person is but not as insightful as it is used… really not meant to gauge a person, but a population…

(eat more) #47


Since Body Fat Percentage calculations use total body weight and not estimates of lean muscle mass and fat, BMI can not determine between the overweight and the more muscular.
(bold added by me)

or bone density/size, inflammation, hydration, etc…the tool for getting the data (scale) is flawed so the result will always be flawed

just my $.02 :slight_smile:

(Brian Miller) #48

BMI is a tool, and arguably not the best tool by any means to be used in gauging your goal weight. For some it might be useful but for others downright harmful. For individuals who are just marginally more dense to achieve the highest end of normal would require losing lean mass which is ridiculous. Many others will see the number as unobtainable and simply quit rather than shoot for a different goal.

“If all you have is a hammer, everything looks like a nail”

(Barbara Greenwood) #49

Body fat percentage is a much better indicator of health. According to my bioimpedance scale (yes, I know they’re not that accurate) mine is somewhere in the high 40’s. I can easily afford to shift another 60lb of fat.

(Clare) #50

Precisely so - BMI is somewhat useful at population level and utterly useless for individuals.

(Bob Weiman) #51

Six sigma class flashback!

(8 year Ketogenic Veteran) #52

This. And the BMI defense is attempting to piss on my parade. Not gonna succeed tho. Giggle. I love this thread.


Yes, except pissers.

I am exceptionally dense, like @richard, we are two incredibly dense individuals. LMFAO

I love that. The DEXA scan was one of the best things I ever did for myself these three years ketogenic.

Tons of muscle. We’ve both had DEXA scans. Our LBM is our own personal business.
For those of you who decide to look at me, or Richard or anyone who does not look slim to you, and decide they are doing things wrong somehow?
Why is it your business how much body fat I carry?

@devhammer, that sweet man, started this thread out of light heartedness, kindness, and caring.
And then …a killjoy defense of the BMI. SMDH
Here’s an idea: Make a topic in defense of the BMI. In the science section. We’ll leave our tear down of BMI over there too. Heh


And this is why I don’t put much stock in BMI…


If you want to cherry pick to make yourself feel better, that’s fine, but if you take pics of 100 people who are overweight per BMI, I’d still wager that the majority of them could stand to lose weight.
And that’s all “overweight” means — carrying more pounds than is ideal. It’s not a value judgement. Just because terms like overweight and obese have come to be loaded words with a certain connotation, doesn’t mean that the definition of those words has changed.


I saw more than one, but that’s the one I copied. Sure, some were what I would consider overweight/obese, etc. But I did see several that seemed wrong to me. I’ve watched my BMI carefully during my journey, and can’t wait for it to “just” be overweight, BUT I doubt I will ever get out of the overweight “category” before I come to my goal weight (whatever that might be).


Only on my scales that probably mostly guess. I’m not concerned right now. I know I have a ways to go. A DEXA scan will be in my future, eventually.


I think I reached that weight last year when I was maintaining. Had lost down to past really where my goal weight was, partially due to some health issues, but found myself being able to maintain at a few pounds heavier without much thought involved. Knew how to eat…Ate that way every day…maintained for months that way…Decided that was probably the weight my body really preferred to be at and I was good with it.

Gained a few pounds over the winter, but very close to being back to my Phinney weight.

(Banting & Yudkin & Atkins & Eadeses & Cordain & Taubes & Volek & Naiman & Bikman ) #62

I would take that as 230ish as that’s my stall point. I have to do things to get below, but can just eat straight semi-lazy keto to get there.