How ideal is "normal BMI"? Should it change as we age?

goldthistime

"Perhaps the most convincing data come from population studies indicating that whereas obesity (BMI>30) is associated with higher all-cause mortality, overweight (BMI 25–29.9 kg/m2) exhibits the lowest mortality risk. "

"The ‘obesity paradox’ refers to observations that run counter to the thesis that normal weight (BMI 18.5–24.9 kg/m2) provides the lowest mortality and higher weight is associated with greater mortality. We argue that the weight of lowest mortality is influenced by aging and chronic disease, with mortality advantage extending into the overweight and even class I obese ranges under some circumstances. A focus on quality nutrition, physical activity, fitness, and maintaining function in these weight ranges may be preferable to a focus on intentional weight loss, which has uncertain effects. The ‘obesity paradox’ is no ‘paradox’ if one defines and interprets ‘ideal’ weight appropriately."

http://www.nature.com/ijo/journal/v39/n1/full/ijo201459a.html

Note: I haven't read the entire article just yet. I'm hoping this isn't another causation/correlation thing, (where sick people are skinnier, skewing the results).

On a personal note, I am less than 2 lbs away from crossing over into normal weight BMI. Strongly considering body recomposition instead of further weight loss.

_John_

I don't understand why anyone can't conduct a study linking survival of a catastrophic illness with overall lean body mass (likely to be higher in the overweight/obese) and strength parameters. Surviving a significant lean body mass loss would be most likely in these individuals.

I seldom see that discussed in the papers but it's my "theory" as to why that weight group "survives" catastrophic illness the best.

DeguelloTex

I'd be massively surprised if it's anything other than correlation. In addition to the skinnier/sicker, a lot of muscular, athletic, healthy people are BMI overweight.

I still have some fat to I'd like to lose, but much net gain in bulk will push me out of normal and into overweight. I can live with that.

goldthistime

_John_ wrote: »

I don't understand why anyone can't conduct a study linking survival of a catastrophic illness with overall lean body mass (likely to be higher in the overweight/obese) and strength parameters. Surviving a significant lean body mass loss would be most likely in these individuals.

I seldom see that discussed in the papers but it's my "theory" as to why that weight group "survives" catastrophic illness the best.

If your theory were correct, then, in preparation for the possibility of a catastrophic illness, we should not aim for normal weight. Agreed? I ask not because I am too lazy to continue, but rather because I wonder if, although I say "health" is my goal, it's only vanity.

_John_

goldthistime wrote: »

_John_ wrote: »

I don't understand why anyone can't conduct a study linking survival of a catastrophic illness with overall lean body mass (likely to be higher in the overweight/obese) and strength parameters. Surviving a significant lean body mass loss would be most likely in these individuals.

I seldom see that discussed in the papers but it's my "theory" as to why that weight group "survives" catastrophic illness the best.

If your theory were correct, then, in preparation for the possibility of a catastrophic illness, we should not aim for normal weight. Agreed? I ask not because I am too lazy to continue, but rather because I wonder if, although I say "health" is my goal, it's only vanity.

I wouldn't argue that one shouldn't aim for normal weight, but care more about fitness/overall muscle mass than weight.



Just as an example, given the same body fat % and height, someone in the normal range is less likely to be as strong as someone falling in the overweight range. In this simplified hypothetical, the overweight person is almost always stronger, with more calories available for recovery (from fat deposits and lean mass) before function is completely lost.

Jruzer

I have seen some of this before and think it's interesting. I have heard that there are some potential disclaimers associated with this, as you said. A prime example is cancer patients who have lost weight due to chemo.

One potential hypothesis I heard is that a little reserve of fat can be a buffer against illnesses that affect the elderly, so that mildly overweight people can better weather such diseases as pneumonia than "normal" weight individuals.

It's good to see the broadly prescriptive concept of BMI getting some scrutiny.

girlviernes

I would say if you are older and in bmi 20-30 I wouldn't be particularly concerned about changing weight, make sure to keep up your activity and strength, eat well, and let your body find its "happy" place.

Stacescotty

Those studies need take age into account. Of course a 45 year old overweight person will be more likely to survive and recover from the same illness that kills a thin 75 year old.

Kalikel

A normal amount of fat will get you through a short illness and is a good and healthy thing to have.

BMI is extremely useful for people who don't really get how fat or skinny they really are.

It's not perfect, but it's good enough.

IdLikeToLoseItLoseIt

A recent study demonstrating that the protective benefits of an overweight BMI disappear after accounting for lifetime weight history, specifically highest weight ever achieved.

http://www.weightymatters.ca/2015/08/guest-post-lifetime-peak-weight-and.html?m=1

As with anything in science, nothing is ever as simple as it seems. The more any topic is thoroughly researched, the more complex and blurred definitive conclusions become, especially regarding a topic with as many co-factors as weight and mortality.

Machka9

The normal BMI range works for me ... always has, even before BMI was a thing.

In fact, I'm most comfortable in the lower half of the normal BMI range. That's when I feel the best, have the most energy, etc.

Happily, I'm 48 and back down into the lower half of the normal BMI range again.

MoiAussi93

Jruzer wrote: »

I have seen some of this before and think it's interesting. I have heard that there are some potential disclaimers associated with this, as you said. A prime example is cancer patients who have lost weight due to chemo.

One potential hypothesis I heard is that a little reserve of fat can be a buffer against illnesses that affect the elderly, so that mildly overweight people can better weather such diseases as pneumonia than "normal" weight individuals.

It's good to see the broadly prescriptive concept of BMI getting some scrutiny.

That's exactly what I've read. Everything I've read indicates this is the proverbial few extra pounds that could be protective, NOT actually being obese. And it's only in old people. Young people should stay at a normal BMI.

So older people at a BMI of , for example, 27 or 28, might be quite healthy if they exercise. And if they happen to get sick, they have a little extra to help them get through it.

My only concern is that people looking for an excuse to stay very overweight will misinterpret this. Especially in younger people, being overweight does far more harm than good.

lemurcat12

IdLikeToLoseItLoseIt wrote: »

A recent study demonstrating that the protective benefits of an overweight BMI disappear after accounting for lifetime weight history, specifically highest weight ever achieved.

http://www.weightymatters.ca/2015/08/guest-post-lifetime-peak-weight-and.html?m=1

As with anything in science, nothing is ever as simple as it seems. The more any topic is thoroughly researched, the more complex and blurred definitive conclusions become, especially regarding a topic with as many co-factors as weight and mortality.

Very interesting.

cafeaulait7

I think mildly overweight may be the healthiest if the person also has good fitness and good muscle mass (more than 'mildly' for muscly guys).

I know I was not overweight at about 21 when I got a disease it took well over a year to diagnosis (it took changing docs to be more accurate). I lost 40 lbs while trying to get a Dx. That ended up with me being just over 85 lbs! I started out very fit, thank God, but I really would have preferred to have some extra poundage to lose. I had to force myself to eat as it was, and that's much harder than it probably sounds on here The disease was really easily treated, and I gained dozens of lbs of muscle quickly with treatment and then backpacking for months after I felt better in a month or two.

I also had a youngish (38) cousin who basically died from starving while on chemo, too She was considered terminal, so no feeding tubes or anything, but she really did get to a weight that is often fatal on its own. I bet she's not the only one out there like that

withoutasaddle

Can't read the article now, but it almost sounds like an excuse to stay overweight to me

MarcyKirkton

I made the mistake of googling "ideal weight" for my age and height. Omigosh, I laughed. The weights suggested were what I weighed probably in my early 20's!

Forget that. Then I found another site that said, basically, the weight I'm at right now is perfectly healthy at my age. More to the point, that lower weight would not appreciably change my health status. OK, that actually sounded right to me. I'm 2 lbs away from being in the government's established healthy BMI range.

So the way I look at it is that 2 more lbs is for health. After that, I'm on "vanity" time. I'd just like to lose a bit more so I lose some of my stomach. But I don't think losing down to 118 or 112 is remotely sensible at my age. Vanity is in the eyes of the beholder. Lots of women who are super thin and older like that. Fine with me, but I think they look pretty sickly. By contrast, I think the weight I'm at now looks a bit too matronly. That's all subjective, obviously.

Anyway, yes....I think appropriate weights change with age.

Packerjohn

_John_ wrote: »

I don't understand why anyone can't conduct a study linking survival of a catastrophic illness with overall lean body mass (likely to be higher in the overweight/obese) and strength parameters. Surviving a significant lean body mass loss would be most likely in these individuals.

I seldom see that discussed in the papers but it's my "theory" as to why that weight group "survives" catastrophic illness the best.

No study but a sample of 1 At age 57 I had a case of sepsis, which is a blood infection that often result in death or at best severe damage to the heart, kidneys and other organs. I was in the hospital for a week and lost 20 pound basically of muscle and had to use a walker to get around for a month. Good news was no long term damage.

When I came down with this I was 6'2" and 210 lbs or a BMI of 27. I've been a lifelong weight trainer and runner. A couple years before I got sick I did a series of testing at the human performance lab of a local university and was in the top 1% of my age group for muscle strength and VO2 Max so I think I can legitimately say I was somewhat muscular as opposed to just an extra 20 pounds or so of sloppy fat. I had several of the medical professionals that worked with me say I had a case bad enough to kill most people and they felt the fact I was in decent shape made the difference. Don't know if carrying around an extra 20 or so pounds of fat vs muscle would have helped.

Jruzer

lemurcat12 wrote: »

IdLikeToLoseItLoseIt wrote: »

A recent study demonstrating that the protective benefits of an overweight BMI disappear after accounting for lifetime weight history, specifically highest weight ever achieved.

http://www.weightymatters.ca/2015/08/guest-post-lifetime-peak-weight-and.html?m=1

As with anything in science, nothing is ever as simple as it seems. The more any topic is thoroughly researched, the more complex and blurred definitive conclusions become, especially regarding a topic with as many co-factors as weight and mortality.

Very interesting.

In reading through the linked study, it seems to me that the claim is that formerly overweight people are still at much higher risk than never-overweight people. That's kind of depressing. Am I misreading?

goldthistime

IdLikeToLoseItLoseIt wrote: »

A recent study demonstrating that the protective benefits of an overweight BMI disappear after accounting for lifetime weight history, specifically highest weight ever achieved.

http://www.weightymatters.ca/2015/08/guest-post-lifetime-peak-weight-and.html?m=1

As with anything in science, nothing is ever as simple as it seems. The more any topic is thoroughly researched, the more complex and blurred definitive conclusions become, especially regarding a topic with as many co-factors as weight and mortality.

Thanks so much for sharing this article! But ugh! @Jruzer you are right! If normal weight people have higher morbidity rates than overweight and mildly obese people, but separating out the normal into "always normal wt" and "previously overweight/obese but now normal wt", showed that "always normal wt" had the best morbidity rates, then yes, it MUST mean that the worst morbidity rates were in the "previously overweight/obese but now normal wt" group. I sure hope it is weight loss associated with illness causing this not something like impaired health caused by dieting.

I think personally I am going to aim for the top end of normal weight, but diet down to at least 5 lbs under to start. My thinking is that I don't want to go as low as I was in my younger years, but I still want a little wiggle room for the whole recomposition process.

Speaking of, I read a comment in a recomp thread that stuck with me. The gentleman said that he doubted his own ability to put muscle on quickly because he was over 55. Therefore he thought that the process of bulking wouldn't work well for him, he would end up putting on more fat than muscle in the process. This made sense to me. Recomp seems like the only answer.

Need2Exerc1se

withoutasaddle wrote: »

Can't read the article now, but it almost sounds like an excuse to stay overweight to me

Why would someone need an excuse to stay overweight?

siluridae

Need2Exerc1se wrote: »

withoutasaddle wrote: »

Can't read the article now, but it almost sounds like an excuse to stay overweight to me

Why would someone need an excuse to stay overweight?

There's an awful lot of them.
Starvation mode, muh metabolism, corn syrup, sugar, fat, carbs, I work 25 hours a day and have a trillion kids, all the gyms are populated by intimidating roiders, broke every bone in my body, people don't support me, can't afford counting calories, muh genetics, too many toxins in my body, ruined my body by doing that juicing diet fifteen years ago...

People get very creative when it comes to finding excuses. They usually don't say, yeah I'm fat, I like lots of pizza, bugger off now. It's always out of their control.