BMI and perceptions, what to follow?

(Doing a Mediterranean Keto) #1

I am continuing with my weight loss, using a low calorie keto diet. Now I weight 82.4kg (I have lost more than 20kg …).

According to my height, a BMI of 25 (the transition point between normal weight and overweight) is just below 76kg.

I always have heard that all-cause mortality is lower for the range of 20 to 25, ideally in the middle of the range, which would correspond (22.5) to 69kg.

My wife (she is slim and tall) has told me that if I go below 78kg, she will boycott me. She says that at 75kg, say, I will have too many bones, and she does not like that. In fact, she remembers me when we first met, and I was 75kg, and she says she prefers I have a bit “less bones”.

Today I have gone to a medical control with my doctor, and I have asked her what would be my ideal weight, and she has said 78kg (I have not said anything about my wife). This number has been given after she has weighted me, but she has not used any calculator, and she has not asked me my height, it has been an “intuitive” answer.

Since there is such a consensus, I am wondering. Should I target a weight that officially is overweight? Is there an objective way to decide which is the optimal (for example, medically) weight for me?

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(bulkbiker) #2

BMI has been outed as a fairly useless guide to overall health and I thought something over 25 led to increased longevity for men.

A far better measure is thought to be waist/height where your waist measurement is under half your height.

(Doing a Mediterranean Keto) #3

Thank you. Probably at 78kg I will be close to waist/height being one half, but I believe I will still be slightly above that. So, this means that I should continue going down in weight a bit more than 78kg, no?

(John) #4

It is still my goal to get within the upper range of “normal” based on BMI. I am one of those apparently rare people for whom the ranges tend to apply. I base this on the fact that in my 20s and 30s I was in fairly good physical condition and weight was in the range of 170 to 180, which was fit but not overly thin. When I got up to 190, I was definitely a bit too heavy. Sure enough, 189 is the upper range of “normal” based on my height (6’ 1.5").

I won’t give relationship advice - that’s your fight.

Edited to add:
Regarding waist-to-height ratio. For me, that would be about 36.5" waist circumference. I am not quite there yet - closer to 37.5". And still about 20 pounds above BMI “normal.” So to get that down to about 36, I will probably need to lose most of that last 20 pounds.

(John) #5

Well there is one solution, that also would tend to keep the wife happy: Do resistance exercises - lift weights. Replace fat with muscle. Muscle tissue is more dense than fat, so you will weigh more at the same size, but be overall healthier and likely better looking.

I know it is possible - I am doing that at nearly age 62, with just some basic exercises, but done regularly and consistently.

The BMI scale is based on “average” body composition and does not take into account people with a fairly high ratio of muscle to fat. Weightlifters may have low body fat but end up showing as overweight based on BMI charts.

So if the number on the scale is what matters to your wife, make those extra kilograms composed of some nice big muscles. She won’t complain then.

(Bob M) #6

About the only thing you can say is people at the two far ends of the BMI scale – those too light and way too heavy – have higher rates of death. Other than that, it’s a toss up.

You can do body weight training if you want to get more “buff”.

(Central Florida Bob ) #7

You don’t give your age, but if that’s you in your profile picture, you look to be in your lower 30s. I think that BMI tables emphasize younger people which is why @MarkGossage’s comment might mean less to you.

That said, I’ve thought BMI is junk science from the day they first started talking about it. It’s simply the same sort of association studies that gave us the food pyramid and the Disastrous American Diet that’s killing so many people and not really worth paying attention to. I don’t know if you’re familiar with the Metlife height vs weight tables that were the guideline before BMI, but it’s the same thing. You can’t put height and weight into an equation and get something more important out of it than some sort of height weight ratio.

If you go looking for BMI stories, you find that almost any pro athlete or other fit, strong person, calculates to have dangerously high BMI. When a cardiac patient can have a better BMI score than a professional ball player, the scale isn’t really measuring what matters. If the underweight cardiac patient really does have a better long term health prognosis than an incredibly fit professional, we need to throw out pretty much everything else we think we know about “wellness”. It turns out high BMI (obese or overweight) heart patients do live longer than low BMI ones.

Personally, I’m not sure anything you can measure with a scale matters, but % body fat or % lean muscle mass probably matter more.

(Bob M) #8

This first sentence tells you everything you need to know about the medical system. Obesity “causes” things like heart disease, cancer, etc. Why isn’t it the things that cause obesity that cause heart disease, cancer, etc.? Obesity by itself does not “cause” anything.

#9

What to follow? Perceptions and your own taste if you ask me. Or you can measure your body fat percent. You can’t rely on BMI as it barely uses a few data and there are other important factors, your muscle mass being an important one. People who aren’t particularly muscular and all their little excess fat is on their belly (it’s not uncommon), possibly looks less than ideal with a BMI of 23-25, even 21-22. Lean body with a little pot belly.
I don’t care about my BMI, I don’t have any problem with my weight, I have problems with my excess fat and its effect on my health and looks. That is what matters. A huge or tiny BMI is bad but when it’s around normal, BMI alone is uninformative.

You surely can be very lean at 78kg ,you just need the right muscle mass… Not everyone want to be that muscular though. And it looks totally different than having -10kg muscle and +10kg fat… Way better IMO but we people have different tastes.

#10

I so agree with this! Obesity is a symptom, simple as that.

(Doing a Mediterranean Keto) #11

Today I am at 79.6kg (woohoo! breaking the 8xkg mark is awesome), and I continue thinking where should I stop.

Both my wife and my doctor tell me to stop at 78kg (which is very close) but I think that I still have some fat to lose, and according to my past history, I think my ideal weight would be 74kg.

I am not sure what to do, since I have not found any objective way to decide at which weight I should stabilize.

#12

BMI is a good way to make quick assumptions for “Average” people without lots of math, that’s it. It doesn’t take a lot into account though. Two people the same height with the same weight will have the same BMI, doesn’t matter if one is carrying all fat and the other is all muscle with 5% bodyfat.

EVERY time I’m a a doc appt and the idiot pre-screening me mentions my BMI I say OK thanks, but I don’t acknowledge BMI. Saying it that way ALWAYS leads to “um, what do you mean?” So then I say pretty much what I just did and then follow with “What’s my current BF%?” which they then admit they don’t know. I then inform them that the last half dozen or so BodPoD and DEXA scans have show that around 190lbs of my 205-215lbs is comprised of muscle, so I have less bodyfat than the typical person showing a “good” BMI. THEN the wheels start moving! Gotta teach these “professionals” one at a time!

#13

It’s quite sad they need to be reminded (I hope they have the knowledge somewhere, deeply hidden) to the fact that two humans with the same age, gender, height, bone density and whatever may have very different amount of muscle mass… Or the exact same human at one point and some years later. Isn’t it obvious? We know gaining muscle is possible without steroids and that clearly changes things, BMI goes up while the person (with little fat to begin with) looks way better even if he becomes “obese” according to the not too reliable BMI.
People love oversimplification, it’s quite annoying sometimes. I’ve read so many times that “a man must be over 80kg!”. Oh yeah, even if it’s 10kg excess fat ONLY on his belly, is it what it makes him manly? Not every man is tall and/or muscular, very very many aren’t. That saying is even stupider than BMI as not even height matters.