Being underweight associated with increased risk of death

[Mutant]

Being overweight, underweight, associated with increased risk of death
Medical Studies/Trials
Published: Tuesday, 19-Apr-2005


Compared with normal weight, a person who is overweight or underweight has an increased risk of death, although that risk appears to have decreased in recent years for obesity, according to a study in the April 20 issue of JAMA.

As the prevalence of obesity increases in the United States, concern about the association of body weight and a higher risk of death has also increased, according to background information in the article.

Katherine M. Flegal, Ph.D., of the Centers for Disease Control and Prevention, Hyattsville, Md., and colleagues conducted a study to estimate deaths associated with underweight, overweight, and obesity in the United States in 2000 by using all available mortality data from the National Health and Nutrition Examination Surveys (NHANES). The researchers estimated relative risks of mortality associated with different levels of BMI (calculated as weight in kilograms divided by the square of height in meters) from the nationally representative (NHANES) I (1971-1975) and NHANES II (1976-1980), with follow-up through 1992, and from NHANES III (1988-1994), with follow-up through 2000. The authors then applied those relative risks to the NHANES 1999-2002 data to estimate excess mortality in 2000.

The researchers found that relative to the normal weight category (BMI 18.5 to less than 25), obesity (BMI 30 or greater) was associated with 111,909 excess deaths and underweight (BMI less than 18.5) with 33,746 excess deaths. Overweight was not associated with excess mortality. The relative risks associated with obesity were lower in NHANES II and NHANES III than in NHANES I.

"The differences between NHANES I and the later surveys suggest that the association of obesity with total mortality may have decreased over time, perhaps because of improvements in public health or medical care for obesity-related conditions. However, such speculation should be tempered by the awareness that these differences between surveys may simply represent chance variation and that small differences in relative risk translate into large differences in the numbers of deaths," the authors conclude.

****

Do youself a favor, eat lots! :p

Kind regards

[Whoa182]

Of course people there will be correlations with people who are underweight having an increase risk of mortality. It's very logical when you consider wasting diseases and loss of appetite that comes with illness which contributes to being a lower weight.

Do youself a favor, eat lots!

Be sure not to eat too much and have yourself a heart attack or diabetes, or cancer or neurodegenerative diseases. :)

[Whoa182]

Lets look at a few others studies on weight and mortality...

* In 1985, the National Institute of Health, Centers for Disease Control, and the Department of Health and Human Services published a "special report" stating: "[S]tudies based on life insurance data, the American Cancer Society Study and other long-term studies, such as the Framingham Heart Study and the Manitoba Study, indicate that the weights associated with the greatest longevity tend to be below the average weights of the population as long as such weights are not associated with concurrent illness or a history of medical impairment." [1]

* In 1993, the Journal of the American Medical Association published a study that concluded: "In these prospective data, body weight and mortality were directly related. After accounting for confounding by cigarette smoking and bias resulting from illness-related weight loss or inappropriate control for the biologic effects of obesity, we found no evidence of excess mortality among lean men. Indeed, lowest mortality was observed among men weighing, on average, 20% below the US average for men of comparable age and height." [2]

* In 1995, a study published in New England Journal of Medicine concluded: "Among women who never smoked, the leanest women ... had the lowest mortality, and even women with average weights had higher mortality. Mortality was lowest among women whose weights were below the range of recommended weights in the current U.S. guidelines. Moreover, a weight gain of 10 kg of more since the age of 18 was associated with increased mortality in middle adulthood. These data indicate that the lowest mortality rate for U.S. middle- aged women is found at body weights at least 15 percent below the U.S. average for women of similar age." [3]

* In 1997, the American Journal of Clinical Nutrition published a study on body weight and mortality stating: "We conclude that when appropriate adjustments are made for effects of smoking and underlying disease, optimal weights [for longevity] are below average in both men and women; this appears to be true throughout the adult life span." [4]

[1]NIHNC, CDC, & DHHS. (1985). Body weight, health and longevity: conclusions and recommendations of the workshop. Nutrition Reviews, February, 43(2), pages 61-3.
[2] Lee IM. et al. (1993). Body weight and mortality. A 27-year follow-up of middle-aged men. Journal of the American Medical Association, December 15, 270(23), pages 2823-8.
[3] Manson E. et al. (1995). Body wight and mortality among women. New England Journal of Medicine, September 14, 333(11), pages 677-85.
[4] Solomon CG. (1997). Obesity and mortality: a review of the epidemiologic data. American Journal of Clinical Nutrition, October, 66(4 Suppl), pages 1044S-1050S.

[Mutant]

If you would take the time to actually research the paper instead of shooting from the hip, lol, you would have read...

Neither analyses of weight-stable participants nor analyses excluding early mortality suggest that illness-induced weight loss had an important impact on estimates of excess deaths. Estimates of relative risks for BMI categories were little changed by such exclusions, and, in particular, there was little change in the relative risk associated with the underweight and overweight categories.

So please Whoa192, for your health, PLEASE EAT! In fact, it was shown that being a bit overweight has lesser mortality than being overweight. That, and you won't need to ask your little sister to open the pickle jar anymore. ;)

Kind regards

P.S. still waiting for those 'different numbers' on glycemic loads for refined and whole grains

[Whoa182]

So just throw out all the older studies right? lol - Why would I care anyway? I'm not a typical ad lib person, how many in the actual study were doing CR with the (ON) ... er none? If it was all about weight, I would have carried on eating those pizzas and fries everyday... and still maintained a low bmi.

Besides, I probably eat more than you... and you can see my diet here:
http://en.wiki.calorierestriction.org/index.php/Matthew_Lake%27s_Diet

[dina1957]

In fact, it was shown that being a bit overweight has lesser mortality than being overweight.
I have a good example in my family. My skinny father died at 65, while my overweight mohter made it to 85. ;)

[Snow_White]

Whoa, I took a look at the list of foods you eat, and WOW! You eat a TON of veggies!

I don't really think he has anything to worry about, consuming >1700 kcals per day.

[Mutant]

Well, we got data for the general population. We've got no populations of 120yo CRs with (ON) to compare. You should worry if many people take up the CR lifestyle; who will open stuck jar lids, change car tires or rearrange the furniture? Perhaps we will need to develop a 'Delta' class a la 'Brave New World'? ;)

Anywho, without looking at the studies, it's hard to say what some of them conclude (it might not be what you think). A couple from you excepts mention 'lean' men; that doesn't mean 'underweight' to me, but rather around 10% bf. A booby builder in contest shape is 'lean' at 240lbs.

I looked at your diet. Question: does the typical CR eat a lot of low nutritional density food? I mean, 50g of salmon filets?!?! Beef, it's whats for dinner. :)

Kind regards

[treefrog]

Also, using BMI can be very misleading. They really need to use bodyfat.

My boyfriend is a weight lifter, and according to the BMI charts he is obese, but he is definitely not. He has a lot of muscle, and since muscle is more dense (weighs more than fat for the same volume), his weight is higher, but not his bodyfat.

That's all I have to say.

[Whoa182]

Heres a quote from an article on longevity from the sptimes.com

"Perls' New England Centenarian Study and similar work elsewhere have found, for example, that 100-year-old men are always thin."

I might be thin See my pics (http://www.matthewlake.plus.com/photos.htm) but I am not weak, I can still do what I did when I was 8 or so pounds heavier. I still compete in football matches against other adults and have no problems, even play football for as much as 5 hours and still go on! I also frequently do resistance training :)

You should take into account the studies done on people who happen to be thin, but eat a very healthy diet. One study showed that exercisers tended to have similar and even lower body fat levels than CRers but did not see a reduction in T3, and only the CRers had this, which has been correlated with increase lifespan in animals.
Also consider the fact that I and other CRonies have two important factors that indicate increased life expectancy like reduced body temperature and extremely low fasting insulin levels with high insulin sensitivity. Also the average CRer has no inflammation, hearts that are 15-20 years younger, no risk of type 2 diabetes, heart disease or stroke, and also have low risk of cancer. All these diseases come under the top killers.[2][3][4][5][6]. Also CR works in every species ever tested, and in normal weight animals it makes them mostly underweight.

I'll take my chances...

References
[1]Keys to long life seen in the old
http://www.sptimes.com/2004/08/31/State/Keys_to_long_life_see.shtml

[2]People who have a lower body temperature live longer, as do those with lower levels of insulin
http://news.bbc.co.uk/1/hi/health/2167316.stm

[3] Calorie Restriction Appears Better Than Exercise At Slowing Primary Aging
http://www.sciencedaily.com/releases/2006/05/060531164818.htm

[4] The 10 leading causes of death in the United States in 2002
http://www.cron-web.org/

[5] Calorie restriction drastically reduces risk of heart attack, stroke and diabetes
http://mednews.wustl.edu/news/page/normal/851.html

[6] Caloric restriction appears to prevent primary aging in the heart
http://mednews.wustl.edu/news/page/normal/6362.html

[Mutant]

Never-the-less, it appears in the study above that the underweight (presumably from not eating enough, id est, calolric restriction) have a greater mortality rate than those of normal weight and slightly overweight. Evidently, caloric restriction doesn't work for everyone.

Kind regards

[Whoa182]

Presumably from not eating enough? Thats not good enough... we don't know why they were underweight. And also, CR does NOT work ever for Adult onset if very good nutrition is not given, or if one weight crashes. It has to be done slowly :) Something that was only learned in the 1980's by walford, after 50 years of people saying adult onset cr wont work.

Did you even take a look at those references?

caloric restriction doesn't work for everyone

CR has already extends maximum and average lifespan in humans, Okinawa is the best example of this. Even though they been de-Calorie restricting since the 1960's.

They used to eat 40% less calories for half their adult lives, with having an adequate diet, but still deficient in vitamin D and b12. But they still did good and had 40-50x the number of centenarians of most other countries. They used to eat around 500 less calories per day than n.america

Compared to Americans, Okinawan elders
are 75% more likely to retain cognitive ability
get 80% fewer breast and prostate cancers
get 50% fewer ovarian and colon cancers
have 50% fewer hip fractures
have 80% fewer heart attacks

[1] Okinawa Centenarian Study data presented at the American Geriatrics Society annual meeting, 2001; cited by McCord H, & McVeigh G, (2002). NutritionNews: "Magic" Appetite Shutoff from the Orient. Prevention, January, pages 52-3.

[2] Kagawa Y. (1978). Impact of Westernization on the nutrition of Japanese: changes in physique, cancer, longevity and centenarians. Preventive Medicine, June, 7(2), pages 205-17.

[ItsTheWooo]

So just throw out all the older studies right? lol - Why would I care anyway? I'm not a typical ad lib person, how many in the actual study were doing CR with the (ON) ... er none? If it was all about weight, I would have carried on eating those pizzas and fries everyday... and still maintained a low bmi.

Besides, I probably eat more than you... and you can see my diet here:
http://en.wiki.calorierestriction.org/index.php/Matthew_Lake%27s_Diet

Do you ever just eat something normally? (like, because the mood struck you and your body was hungry?)

[ItsTheWooo]

Well, we got data for the general population. We've got no populations of 120yo CRs with (ON) to compare. You should worry if many people take up the CR lifestyle; who will open stuck jar lids, change car tires or rearrange the furniture? Perhaps we will need to develop a 'Delta' class a la 'Brave New World'? ;)

Anywho, without looking at the studies, it's hard to say what some of them conclude (it might not be what you think). A couple from you excepts mention 'lean' men; that doesn't mean 'underweight' to me, but rather around 10% bf. A booby builder in contest shape is 'lean' at 240lbs.

I looked at your diet. Question: does the typical CR eat a lot of low nutritional density food? I mean, 50g of salmon filets?!?! Beef, it's whats for dinner. :)

Kind regards

Jar lids are the least of humanity's problems. Reproduction (thus ourselves) would cease to exist. It is not possible to have healthy offspring while underweight and/or underfed.

[ItsTheWooo]

Whoa, I took a look at the list of foods you eat, and WOW! You eat a TON of veggies!

I don't really think he has anything to worry about, consuming >1700 kcals per day.

1700 cals per day is extremely low for a young man. I'm a 116 lb 5'5 female and that's about what I eat. Whoa should be eating probably like 2500 cals.

[Whoa182]

Do you ever just eat something normally? (like, because the mood struck you and your body was hungry?)

I eat so much, that it feels like i'm constantly eating :lol: - I frequently get comments from friends and family asking me "Do you ever stop eating!?"

Although i'm not exactly strict on my eating, if I go over by 300 cals or so it doesn't bother me at all, I don't even make up for it the next day so I never freak out or anything lol. If I am hungry though (which is rare) I just grab a snack, EVEN if that meant my calories were over my target. My weight stays VERY stable, it never budges down or up, although I hope it goes up as I get older :)

I hope that answered your questions :S

[Snow_White]

ItstheWooo:

111 pounds x 12 = 1,332 -- isn't that the formula that most people use to determine their caloric needs? If so, then 1700 should be a pretty safe number (?). :q:

[Whoa182]

Don't know, but I find this predicts my calorie needs quite accurately http://www.scientificpsychic.com/health/cron1.html - It seems I have this huge buffer capacity, meaning I can go so many calories under and over and it doesn't really make much of a difference to my weight...

I mean I maintained the same weight since december to like june-july, was consistently the same every morning. But I gained 3 pounds (intentionally) since that time and calorie needs still havent changed much.

I also do Power Yoga

[Snow_White]

Thanks for the link, I'll check that out. :)

[ItsTheWooo]

111 pounds x 12 = 1,332 -- isn't that the formula that most people use to determine their caloric needs?

That formula is nonsense and has no scientific basis.

Weight and caloric need to not increase in linear proportion. The core body systems (brain, homeostatic processes) require the overwhelming majority of caloric needs. Muscle and fat and bone takes up relatively little energy.Therefore, any formula that calculates energy need by some weight times a factor is not going to be accurate except for a narrow range of body types. Even then, it still won't be accurate (because of how different our lifestyles and metabolisms may be).

The factor needs to be higher in underweight people and lower the more overfat you become. Therefore, an underweight person of 110 pounds does not need half the calories of an overweight person of 220 pounds. Their caloric needs will be more similar than dissimilar, actually... because 110 lbs of fat/muscle/bone do not use all that much energy relative to life support.

116 x 12 = 1392, and I assure you, if I ate that little I would start losing some weight. I just checked fitday, this month I've averaged 1800 cals. I've put on a little weight, but not much at all. My maintenance cals are more like 1700.

[ItsTheWooo]

I eat so much, that it feels like i'm constantly eating :lol: - I frequently get comments from friends and family asking me "Do you ever stop eating!?"

That really doesn't mean you eat a lot. A giant plate of grass with a little teeny piece of meat (or starch, or nuts, etc) does look like a lot of food to people who have no idea about calories.
Also, if your life revolves around preparing meals, and focusing on food, it seems as if you are always eating, even if you're actually not.

Before I stopped restricting food I was always told how much food I ate (except for people who understood the principle concept of calories/metabolism, i.e. dieters).

It is completely illogical to say you restrict cals but then to also say you eat a lot and are always eating... like an anorexic who says they feel stuffed after eating an apple, or that they are never hungry (which may be true to their perceptions, but their perceptions are disturbed and incorrect). Not saying you are anorexic, just that your perceptions do not jive with what you are actually saying you do.

[TarHeel]

While recognizing that anecdotal evidence is completely worthless, my fairly skeletal father lived to be almost 91. He practically lived on sugar.

On the other hand, my somewhat overweight, but not by much, mother lived to be 87. She considered fat in any form to be the devil. I'm not reading it as a big difference/deal.

Kay

[Whoa182]

Also, if your life revolves around preparing meals, and focusing on food, it seems as if you are always eating, even if you're actually not.

Well I go to college from 10pm - 3pm then work from 5pm to 8:30pm. Meal preparing takes about 5 minutes max, data input about 3 minutes a day and I find time to volunteer in the hospital. So I wouldn't say my life revolves around preparing meals.

It is completely illogical to say you restrict cals but then to also say you eat a lot and are always eating...

No it really isn't, not when you consider all my food is low calorie and I spread it out throghout the day with snacks between each meal.

like an anorexic who says they feel stuffed after eating an apple,

Well thats ridiculous

or that they are never hungry (which may be true to their perceptions, but their perceptions are disturbed and incorrect).

What? I'm hungry when its time for dinner... :yum:

Not saying you are anorexic

Good

your perceptions do not jive with what you are actually saying you do.

It's not rocket science... I have successfully found a way to eat until my hearts content and end up consistently below 1800k/cal a day without even TRYING, and without going through long periods of hunger or even feeling like i'm restricting. People design such crappy meal plans no wonder why some may be confused when I say I have no excessive hunger problems. I feel no different, hunger wise, than when I was eating normally. You just have to believe me on that one...

[Mutant]

Presumably from not eating enough? Thats not good enough... we don't know why they were underweight. And also, CR does NOT work ever for Adult onset if very good nutrition is not given, or if one weight crashes. It has to be done slowly :) Something that was only learned in the 1980's by walford, after 50 years of people saying adult onset cr wont work.

Did you even take a look at those references?

Ya, I looked at the references. But more to the point as YOU were responding to my post, did you look at the study I references? If you did, you would have noted that the results were unaffected by loss of weight due to disease and in fact there were no large shifts in weight. It seems you don't want to accept this study cuz... it doesnt fit your view of the world. When the CRoners all migrate to Ghana, don't drink the Koolaid, Whoa. The results are straighforward, if you have a problem with the study at least give it a look-see and don't dismiss it out-of-hand.



CR has already extends maximum and average lifespan in humans, Okinawa is the best example of this. Even though they been de-Calorie restricting since the 1960's.
<snip>

I know you got a real Jones on for the Okinawans, but they are hardly the *proof* of your dear hypothesis. At most the results are suggestive. You know what they say, when all ya got is a hammer, every problem looks like a nail...

"...if I had a hammer, I'd hammer in morning, I'd hammer in the evening, all over this laaaaaand"

Kind regards

[dina1957]

I eat so much, that it feels like i'm constantly eating :lol: - I frequently get comments from friends and family asking me "Do you ever stop eating!?"


It's because you eat food food that us low in calories and nutriotion. I eat only 3 meals a day, but sufficient animal protein and fat, so I am not hungry and don't munch on raw vegetables all the time. Eat more protein and fat and you will stop grazing.

[dina1957]

While recognizing that anecdotal evidence is completely worthless, my fairly skeletal father lived to be almost 91. He practically lived on sugar.

On the other hand, my somewhat overweight, but not by much, mother lived to be 87. She considered fat in any form to be the devil. I'm not reading it as a big difference/deal.

Kay
Longevity is all about good genes, not food per se. My Dh gradma is 90, doing great, was obese all her life and thinks pork fat rules, a meal is not a meal without salted port fat, washed down with tea with lots of real sugar. But her entire family lived to really old age, her older brother died at 98, and older sister lived to be 102.

[Analog6]

An interesting thread. Being (unhealthily) underweight (as opposed to a genetic predisposition) means you can be more susceptible to disease as the body has less resistance. If it is caused by malabsorption of nutrients in the gut, it means you may be undernourished in the vitamins and minerals are.

And the BMI charts are a bit off for muscular folk. I think they go a bit too low. For me it goes down to 121 lbs ( 54.9 kgs) and up to 159 lbs (72 kgs). At 5'&' (170 cms) I reckon I'd be severly underwieght at 55kgs!

I knew a lady years ago who was about 5'5" and would only have weighed about 85 lbs. And she ate like a horse, the doctor put her on special diets to gain weight, but nothing worked. And she was starting to suffer brittel bones due to malnutrition. So it is not all beer and skittles being thin.

[pennink]

Friend of mine is over 50, 5'6" and 100 pounds. Brittle bones are her problem too.

[Whoa182]

Longevity is all about good genes, not food per se. My Dh gradma is 90, doing great, was obese all her life and thinks pork fat rules, a meal is not a meal without salted port fat, washed down with tea with lots of real sugar. But her entire family lived to really old age, her older brother died at 98, and older sister lived to be 102.

About ten or so years ago that was the consensus, not anymore. Just by changing the genetic expression of the genes you have, could drastically alter the aging process. People blame their development of disease on genes a lot saying "its not my fault, its my genes", but really, genes only play a part in 25% of how long we live (might be much less) and the rest is how we cope with stress and what we eat. More importantly, how much we eat. It's thought that the average person has the genetic potential to live to around 85.

If it were all about genes then all the past and current CR longevity records would not have been made, because the mice used are genetically identical to each other! and ad lib would not significantly differ from CR'd. But they do! and how many calories they eat is always the most important factor. It makes their genes change expression to a more 'youthful state'.

Heres an interesting article on identical twins. Same genes, same rate of aging right? NO not quite!

Genes reveal little on longevity
http://detnews.com/apps/pbcs.dll/article?AID=/20060928/LIFESTYLE03/609280309/1005/LIFESTYLE
Thursday, September 28, 2006

"But recent studies find genes may not be so important in determining how long someone will live and whether a person will get some diseases -- except, perhaps, in some exceptionally long-lived families. That means it is generally impossible to predict how long a person will live based on how long a person's relatives lived."

"esauro does have a living sister, an identical twin. But she and her twin are not so identical anymore. Her sister is incontinent, she has had a hip replacement, and she has a degenerative disorder that destroyed most of her vision. She also has dementia. "She just does not comprehend," Tesauro says."

[dina1957]

Whoa,

I won't trade a life of deprivation for a remote posibility of life extension. Once, you can do everything in your power: undereat, eat all organic, non-fat, all vegetable, flavorless and tasteless food;drink absoutely no alcohol - we all now it is toxic;exercise every day- and get hit by a bus at early age or get into a car accident;) Besides the fact that being too skinny is not appealing in both sexes, and only is sort of acceptable look for pre-teens and teens, someone who is a bit older (females for example) not only do not have a younger appearance (fat makes facial skin supple) but also at a risk of early menopause and associated risk of heart desease and osteoporosis. So, on one hand CR suppose to be life prolonging - in mices, on the other hand - being too thin posses problems in humans. CR and low body weight/fat is a signal for those species to stop reproducing, since they won't be able to support/nourish offspring. A well nourished mother can provide all nutriotion for the infant via breast milk, but a baby won;t survive if the mother is on CR diet.
Human obsession and passion for food has a very good reason- a well nourished body can survive deseases and natural disasters better than underfed weaklings. Constant undereating results in undernourishment and weak immune system.
There is an old Russian prowerb, it sounds roughly like this in English: while fat one getting skinnier, a skinny one will die. So if tomorrow for some unfortunate circumstances there will be shortage of food, the chubby ones will outlive the slims.;) This is why older generation (who actually experienced famine first handed) value nutriotionally rich food so much!
Regards,
D.

[Mutant]

I think I am identifying another problem of the underweight besides early death; evidently the underfed cannot commit to a post. Whoa182, do you know that you have edited 5 of the 9 posts you have made to this thread alone? I think I'm starting to understand why some boards disable the edit function...

Kind regards

[Newbirth]

Longevity is all about good genes, not food per se. My Dh gradma is 90, doing great, was obese all her life and thinks pork fat rules, a meal is not a meal without salted port fat, washed down with tea with lots of real sugar. But her entire family lived to really old age, her older brother died at 98, and older sister lived to be 102.Yep, my Dad has type 2 diabetes, eats lots of starches and has to inject insulin because...well, if you follow the ADA guidelines, diabetes always gets worse over time. He lost weight because his doctor said to, but is now putting it all back on. He's in a wheelchair (has been for almost 40 years now) and doesn't work out or clean his house. I refuse to visit him where he lives. He lost all his teeth years ago. He's 83. So yeah...good genes there.

My mom is on Weight Watchers and works out. She's in good health. She's 70.

Hopefully I got those good genes and can enjoy a long life...free of diabetes of course because I am low-carbing. :)

[Newbirth]

I think I am identifying another problem of the underweight besides early death; evidently the underfed cannot commit to a post. Whoa182, do you know that you have edited 5 of the 9 posts you have made to this thread alone? I think I'm starting to understand why some boards disable the edit function...

Kind regardsDepends on the reason for editing. Many of my posts get edited simply because I'm too lazy to proofread and then I find all sorts of spelling and grammar errors.

[Edit: I did it in this post...fixing spelling now!]

[Whoa182]

I type around 80-100 words per minute... so I sometimes have a lot of mistakes. Sometimes I just add more things that I think is relevant too.

[Whoa182]

All my great grandparents, and 3 of my grandparents all made it to 85, I never seen them eat anything but junk food! lol. And they smoked all their life too, which led to them all dying of lung cancer.

[ItsTheWooo]

I edit all of my posts, too. (... and also type 80-100 WPM high five ! :lol: )

IMO, editing implies more thought and care into what you say than does never editing...

[Angeline]

I always edit my posts too, mostly for errors and awkward sentences.

Although I never alter the meaning of my posts, I just make small changes to make it them readable or correct an obvious error.

However, If I want to add anything or make a new point, I'll make a new post.

I don't think I would participate on a board that doesn't allow editing. It would be too frustrating.

[Whoa182]

Just read over this paper and It was done on people living in a poor country. Alcohol and smoking was very low. They found a Reverse J shape mortality for BMI. So many things complicate these sorts of studies, also be aware the fact that these were probably not getting the best possible nutrition in all groups. Right now the whole BMI-Mortality is very inconsistent with lots of different things showing up. It just shows that it depends on how well you control certain factors... maybe soon we'll get better answers.

From this paper:

"the lowest mortality was observed in women with BMIs of 16.39–20.71 and in the quartile grouping with BMIs of 18.42–19.61"

Lower than 16.39 seen a significant increase in mortality and higher than 20 was a slight increase in mortality relative to the intermediate group.

Read it for free here:
http://www.ajcn.org/cgi/content/full/77/2/341