At the risk of stepping into the middle of a fight… I must suggest that anyone interested in the relationship between fatness, fitness, and health read a fantastic, complete, and highly accessible scientific review on this subject written by Vojtech Hainer, Hermann Toplak, MD, PHD, and Vladimír Stich, MD, PHD. For the TL;DR crowd:
1. It is inarguable that being fat and sedentary is terrible for your health.
2. Quite a few recent, large, and well-crafted studies have dug into figuring out which is more important for preserving health: being normal weight or being active. Almost all—and particularly the better crafted studies that have used independent and scientifically rigorous measures of fitness rather than surveys—show being active is the more important factor, even if the activity does not succeed in causing one to lose weight.
- The relative risk of dying per year, by fitness and fatness.
The numbers in this figure represent the relative risk of dying in a given year, broken down by fitness and fatness; lower numbers are better. The healthiest group in this study were the (moderately) fat, fit group.
A prospective JAMA study from 1995 showed nicely that becoming fit had a significant effect on both all-cause mortality and cardiovascular mortality. The effect size wasn’t small. For every minute one could last longer on a treadmill, the relative risk of death in a given year was reduced by 7.9 percent.
3. Therefore, just because someone is fat (or looks fat) doesn’t mean they’re unhealthy. Additionally, even if exercise didn’t work for you (i.e., it didn’t make you thin), you are still deriving a massive benefit from exercising even if you remain fat. The amount of exercise needed is quite small, 20 minutes of moderate exercise (enough to get your breathing rate up, not to drive you into a drenching sweat and gasps for air), three times a week is enough.
Updated:
Here is data for women, around the same question. This study isn’t quite as clean as the one for men I cited above.
In this study—the Lipid Research Clinics Study—both fatness and fitness were relevant predictors for health. A more ethnically diverse population of subjects was involved in this study. The results from slightly overweight and massively overweight individuals were combined, perhaps clouding the relationship in the other (men-only) study was able to demonstrate.
Golob – The Lee study data you cite was from a cohort of 95% caucasian with 80% of them being college graduates. That raises a few questions about how applicable the results would be to the rest of the population. Seems the other studies showed a less dramatic impact.
The Blair study clearly indicates that it is critically important to maintain a constant level of fitness throughout life. Even those that started out unfit and became fit over the 5 year period had over 50% higher mortality than the fit-fit group.
Interesting data, but lots of moving parts with the CRF portion of the study based on genetics it seems. So good genes do count, still, for cardiac health.
@50: Thanks for that tip. Interesting graphs, and I see how they support your point. After a longish and unpleasant* stay in an ICU, I once down around BMI 17.5, which the plots suggest is unhealthily gaunt.
*Not to sound ungrateful re the miracle of modern critical care. My time in the ICU was way better than the alternative I was facing! I love you, ICU people!
@52: I agree on all of your points. The Lee study, I still maintain, was well done–with the major questions being ones of generalizabilty.
It’s clear you dug into the full (and freely available) review article that I linked to at the start. In my summary, I chose the clearest and cleanest data. It’s always a struggle when the vast majority of people won’t even make it through my post, let alone a 4000+ word scientific review article, to get the across without simplifying too much.
Hot damn. This is the least depressing news I’ve heard in ages.
I’m a slightly chubby woman who can run 10+ miles any given day. This study will keep me running despite my physique completely betraying my physical ability:)
Another major factor besides fitness, possibly more important for women at least:
Women and overall mortality –
Lowest beef and pork consumption: 1.00
Median beef and pork consumption: 1.24
Highest beef and pork consumption: 1.63
Men and overall mortality –
Lowest beef and pork consumption: 1.00
Median beef and pork consumption: 1.17
Highest beef and pork consumption: 1.48
Of course, “lowest” beef and pork consumpion is just the 20% quintile, which is still a lot of beef and pork for America. Other studies suggest zero consumption reduces cancer and heart disease risk even more.
http://archinte.ama-assn.org/cgi/content…
@54 Thanks for the response.
The data on the importance of long term fitness was interesting to me. I’ve seen so many other types of studies about smoking, etc. that indicate that risk fades quickly to baseline levels that this really stands out.
The Lee results are somewhat shocking to me that they could produce such a huge spread in mortality outcome. I would love to read the entire thing and look at the data – for better and worse, those results hit directly home with me: college educated white male.
Definitely a kick in the ass to stay off the couch at all costs, and maintain a good relationship with my GP. Thanks for posting this.
@28 Sure, but….:
The good thing about science is that it’s true whether or not you believe in it.”
— Neil deGrasse Tyson
@54: Interesting, understandable, simple, comprehensive, accurate, brief: one can’t be all those at once. But I think your posts consistently find a good balance. One of these days you should do a post telling us about your day job, now that you’re all MDd and residented and what have you.
ah.
“Science”….
Dr Golob;
could you comment on the CDC declaration that the best way to prevent STDs is abstinence until in a long term relationship and monogamy thereafter?
also please compare and contrast the objective science based advice from the CDC with the degenerate behavior Danny advocates.
Let’s be 100% clear – the definition of “fat” in this study is not actually fat. You have a technical definition and a common definition, and you’re using the former to make a point related to the latter. I assume that this slipped your attention, but you should know better. We should all know better.
The technical definition of “fat” in the study you cite is a BMI between 25 and 28 (for comparison, at my height (6-2), that’s between 195 lbs and 218 lbs.) The common definition – as when Lindy and many sloggers say that they’re fat – is somewhat larger than that.
The paper that the same group published in Obesity Research is available full-text, so let’s sum their lessons up up. Both fitness and BMI are significant predictors of excess mortality (an imperfect proxy for health, but the best we have). Fitness has a stronger effect than BMI, so you should take both into account.
It’s really hard to be fit if you’re overweight. Look at fig 3 of the Obesity Research paper. Low fitness (the very bottom quintile) is not evenly distributed. Nearly everyone with BMI < 27 will not have low fitness. Nearly everyone with BMI > 35 will have low fitness.
In other words, fitness is not available on a sliding scale. Health is not available on a sliding scale. If you want to be as healthy as someone who’s lighter, AND your BMI is over 27, you have to be fitter. Not fitter relative to people your size/BMI range. You have to be able to run longer and run harder than them – you have to be just plain fitter.
Damn, I was reading Lee et al (1998) rather than Hainer (2009). Hainer covers more ground,
The article in Obesity Research is Farrell et al, The Relation of Body Mass Index, Cardiorespiratory Fitness, and All-Cause Mortality in Women, Obesity Research (2002) 10, 417–423
The points still stand, though – obesity is bad, and fitness is good. I do wonder what the limits of the relevant work are, because we’re looking at smaller and smaller populations who are both obese (class II or class III) and even moderately fit.
I actually brought this up in that Lindy post, but someone misread my reply as support for Lindy (it was not) and then flamed me so I just dropped it. I think @63 makes a solid point, but there’s still an interesting theoretical point that merits more research in this study. Namely, what are the limits on the BMI level? Is there a point where even good fitness cannot help your life expectancy? At any rate, it’s a good study, but people are going to abuse it. Most… no, biologically speaking, ALL people get fat and stay fat from varying ratio of sedentary lifestyle and overeating (as determined by their level of activity and to a lesser extent genetics). If you stay fit and still stay overweight you would have to be consuming so many goddam calories I almost question who it would ever apply to.
Oop, lost the main point for that reply. Your title says “fatness is a poor way to measure unhealthiness” but that’s not really true. No measure is sensitive enough to capture all irregularities, as this study points out, but it’s still a very valid and reliable measure for outcomes associated with bad health.
Dr. Golob, I love you. And I love science. But science only answers the questions it asks. So has anyone asked (that you know of) the question posed by @29? Is there a correlation between being overweight – however that may be technically defined – and being fit? And does that change as we age?
I know I had a long term weight problem, and only after I turned 41 did my cholesterol and blood sugar become a concern. Reading the comments on Lindy’s and Dan’s posts, I see a lot of 20 and 30-somethings saying “I”m overweight and my numbers are great” but I wonder if that will last. Seeing my step-father battling the end stages of Type II diabetes and all that involves was a well-timed wake up call for me, and an awful way to die for him.
@65 I think that there’s more than one.limit, take this hedging for what it’s worth
First, certainly there’s a limit where you’re sufficiently big and heavy that you can no longer be high cardio fitness (top 2 quintiles), same for moderate fitness (3rd and 4th quintile), even with maximum effort.
Second, there’s certainly a point out there where the additional mortality cannot be made up for by exercise – we can’t get there from here. That’s the latter limit, and it’s probably closer to us now than the former.
“Science. It works, bitches.”
http://abcnews.go.com/Health/cdc-report-…
From Rob’s link @70
“the data for the “not fat” folks are a little skewed because people who are seriously underweight have elevated death rates.”
“Elevated death rates” Yeah, dying people “skewer” results for everybody, I hope they’re pleased with themselves.
Thank you, Dr. Golob! I agree with gnossos @38, and would also like one on how correlation does NOT equal causation!
Obesity alone raises risk of fatal heart attack, study finds
http://yourlife.usatoday.com/health/medi…
@74 And being black raises your chance for heart disease.
75, But one can alleviate obesity by eating properly.
I’ll join the other inspired people. I’m getting up and walking to the vegetable market (1.4 miles one way) now. It beats my normal health plan, which is walk home from the bar.
I don’t think anyone is saying that being overweight is unhealthy…it’s being very obese that is unhealthy. Active people with a little extra weight on them rock, I don’t think anyone is criticizing those people. It’s the people who struggle to walk that everyone is worried about and there are sooo many of them.
BMI is not “fatness”, especially not for fit (muscular) men.
That’s why this study shows that fit men with a higher than average BMI
(due to muscle more than fat for most of them …) had the lowest mortality.
That’s also why the data is different for women than men.
In short the study is good, but the analysis of it given here is just crap.
The study is only measuring mortality. Fat leads to loss of quality of life, diabetes, joint problems, but why do we keep arguing this? Everyone has to agree that being moderate in all things is best. That’s what the science really shows. You can be 20lbs overweight and be fine, but if you are 80lbs overweight, it’s a mistake to say that’s okay.
One of the things I’m surprised no one ever mentions is how different BMI standards are for women versus men… at least compared to what society calls “fat.” Put it this way, as a woman who is 5’3”, I have to be over 145 pounds to make it into the overweight category. From society’s standpoint, that is a pretty generous range. If you asked most people on the street what the idea weight for a woman of that height is, what sort of numbers would you get? 110? 120?
On the other hand, for a 6’ man to be overweight, he has to be over 185 pounds. That seems on the slender slide. The bottom range of normal for a man at that height is an anorexic 135. How many of you know men who top 200 pounds at six feet tall and just look muscular?
Great example – of how diagrams mean science to most people, and how “statistical” charts can be incredibly misleading.
If you look at this another way, the fat people, taken together, have a 5.96 risk of mortality. The not fat have a 3.25 risk. Not fat = less than HALF the risk. So, does this still say what you think it says?
The first thing you learn in a stats class is that you can present the numbers however you want. You can make a chart with data that totally disproves your theory, and make it look like you’re correct. Takeaway: statistics need to be correctly interpreted to have ANY real meaning. Don’t believe everything you see on tv, kids.
@62 No one is talking about sex here except you, so why don’t you go fuck yourself?