I remembered seeing something on the subject in my Physiology texts. It does not answer you question, but may provide some insight.
I've never read anything on age vs percentage of body fat vs mortality that had any credibility. However what I have read is that resistance measurements are not very accurate. The caliper/skin fold measurements are pretty good if done by an expert. Also, we worry way to much about body fat.
I did find a statement in Sport Nutrition for health and performance (2nd edition, pub 2009) which I'll paraphrase:
Proposed body composition standards include some increase in %BF with age rather than imposing the current young adult standard. It goes on to state that a young adult with 24% BF would be encouraged to lose some while a middle aged man would be in the healthy range.
There's also the statement that a lower level of fat body in middle age is associated with lower bone mineral content and an increased risk of bone fracture. IMO, that's probably more for the sedentary, though road cyclists tend to have poorer bone health than say joggers or even pro mountain bikers.
I'll cite some mortality statistics from just one of the studies on activity vs fat reported in Physical Activity and Health, the Evidence Explained (second edition, pub 2009)
The data is from a study of 22,000 men aged 30 to 83. Fitness was measured using time to exhaustion on a treadmill test. Body fatness was assigned as lean (less than 16.7% body fat), normal (16.7 to less than 25%) and obese (greater than 25%).
Fat was measured by hydrostatic weighing, skin fold thickness or both. Average follow-up was 8 years. They adjusted for age, smoking, family history of heart disease and alcohol consumption.
Results: lean unfit men had twice the all-cause mortality of obese fit men.
There are several other studies reported with the same kind of results. Fat is not the issue, physical activity is. That said, obesity is not a good idea, but neither is thin.
You find this stuff in the popular media or from the government.
Al
Originally Posted by
hikeandbike
I've been checking my body fat last few months at my gym with one of those electronic testers. Body fat is usually 15 or 16 % and body mass is 22 or 23. At 15% the chart they use indicates that I'm pretty good for someone my age (60 in 3 months), but not for someone a lot younger. I don't understand why age is a factor. What's the difference if someone in their 20's has a certain % of body fat and someone in their 60's has the same %? I can understand why you have to input your height and weight into the device, but not sure why you even have to program in your age. By putting in an age, does that change the measuring process?
I also don't know what body mass is and what the scores indicate.
Can anyone help?
Thanks.
Larry