There have been a number of studies of late that have concluded that being overweight (not obese, overweight) and elderly is in fact a good combination.
Well, here's another.
This study, published today in the Journal of the American Geriatric Society has Leon Flicker and his colleagues discussing the impact of weight on mortality over a 10 year period in 9,240 Australian men and women.
Their findings?
The minimum mortality risk was found at a BMI of 26.6 and as BMI decreased from there, risk increased, with the risk of death with a BMI at the lower end of the "normal" range being nearly double the risk of those who were "overweight". These results were sustained even when stratified into groups of initially "healthy" versus initially "unhealthy" subjects and when years one, two and three were subtracted from the study to eliminate those who might have lost weight prior to enrolment due to a chronic illness.
The one variable aside from weight that had a tremendous impact was being sedentary. Men who were sedentary were found to have a 28% increased risk of mortality across all weight categories while for women the risk was double!
Class I Obese participants had very similar mortality risks to normal weight individuals though as weight went up from there, so too did risk.
The results aren't exactly surprising. Previous studies have shown the same results and certainly the theory that older folks carrying some excess weight will have greater metabolic reserves to draw on to weather both chronic and acute medical conditions sounds feasible.
The main limitation of this paper is that BMI was used as a surrogate measure of body fat. This becomes problematic in a geriatric population due to both the natural course of aging (loss of muscle and conversion to fat) as well as the fact that BMI does not identify those with greater stores of visceral fat. A minor limitation was that height and weight were self-reported and given that we know self-reported heights and weight tend to make people taller and skinnier than they actually are (a phenomenon that one might expect to be exacerbated by age-related shrinking (there's an easy paper for someone)).
Interestingly though the paper's main limitations actually supports the authors' conclusions that BMI thresholds as we currently understand them likely should not apply to the geriatric population in that either weight is in and of itself protective or that BMI cannot identify risk in the elderly though perhaps fat distribution does (another potential paper), and while the authors for some reason didn't mention it in their conclusion, this paper would certainly suggest that the most important thing a primary care physician might do when faced with an overweight or obese geriatric patient would be to constantly encourage them to be active.
Flicker, L., McCaul, K., Hankey, G., Jamrozik, K., Brown, W., Byles, J., & Almeida, O. (2010). Body Mass Index and Survival in Men and Women Aged 70 to 75 Journal of the American Geriatrics Society, 58 (2), 234-241 DOI: 10.1111/j.1532-5415.2009.02677.x
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How does this jibe with this study:
ReplyDeletehttp://circ.ahajournals.org/cgi/content/abstract/CIRCULATIONAHA.109.887521v1
The question I have is, when is it considered "safe" or "healthy" to put on or carry the extra weight?
I guess my thinking is this -- if a person starts out with a healthy lifestyle (i.e. no tobacco or excessive alcohol use, good diet, regular physical activity, good preventive care, managed stress and a fulfilling life) and gains slowly over time (some years more and some less) so that their BMI ends up in the overweight category, that would provide the best outcome? Or -- would it be more likely that by 70-75, people would have begun losing some fat and muscle, so that slow weight gain or maintaining a healthy lifestyle at a BMI around 30ish that starts to decline with age might produce a good outcome.
I think that for people with the "natural" tendency to gain weight in this particular food and movement environment, maintaining the healthiest possible lifestyle with the least weight gain possible, and as much enjoyable physical activity over the lifespan, is the best most of us can help for. Rather than focusing on weight loss for people with BMIs that settle at a place where they have a good quality of life -- focusing on optimal physical activity, great nutrition, not avoiding doctors because they constantly harass you to lose weight -- is the way to go. Not believing that by carrying extra weight -- in spite of the healthiest possible life you can manage at any given time -- only hurts health, it doesn't help people manage or mitigate risk.
I think it probably jibes fine.
ReplyDeleteThe thought is that if you've made it to a ripe old age with the weight (in the Circulation study and many others middle-aged weight certainly increases risk of death) then the benefits of the weight seem to outweigh the risks.
In terms of why, no one really knows and while it's certainly possible your scenario is a common one (slow gain over lifetime), the weight history of those 70 year olds isn't known.
In terms of weight and age, the rule of thumb I tend to follow is 10 calories fewer burned per day, per year such that a 70 year old burns 500 fewer calories than a 20 year old and I agree with you whole heartedly, it's not about trying to be an ideal weight or BMI, it's about living the healthiest life you can enjoy living.
I'll have to tell my dad, he's been trying to lose his extra 20 pounds for 60 years. He's as active as his arthritis and bad hips allow him to be.
ReplyDeleteThanks for the response.
ReplyDeleteAs someone who works in public health and health communication, I hesitate to pass along the idea that it's either bad or good to carry "extra" weight. And how can any of us know what of our weight is "extra" and what isn't if we're living the healthiest lifestyle we can enjoy?
I guess that I know I'm at higher risk myself of heart disease -- and maybe a few extra peanut butter cups could be cut from my diet -- but if I do have a heart attack in my 50s, and survive it, who can say that the extra weight didn't help with survival at that moment and if I make it into my 70s? I can live with the risks -- I know what it takes for me to weigh 20 pounds less than I do now, and it's not a lifestyle I enjoy or can afford in terms of time -- I would have needed to choose not to be a parent in order to manage it as it requires both very limited calories AND two or more hours of exercise daily -- and I would still have a BMI above 30.
I think keeping physical activity and an overall healthy diet, stress management and avoiding health-harming behaviors (such as tobacco) are going to have to do, even if that means my risk is still higher than someone who is slimmer. My grandparents and parents made it into their 70s and 80s, and they all worried about their weight and felt bad about it -- I would rather not waste time feeling like I don't fit in or I'm not healthy when by anyone's measure, I'm doing the best I can to manage my health overall.
I don't need a study to tell me some important things:
ReplyDelete1. My hips and knees feel better when I weigh less.
2. I can walk much longer and faster when I weigh less.
3. I feel more like exercising when I weigh less.
4. I have fewer episodes of chest pain and tachycardia when I weigh less.
Now somebody please tell me how to lose weight and keep it off.
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