From a post on the practice of calorie restriction last week, pointed out to me just recently:
ABCNews reports a poll showing that 75% of women and 70% of men polled (lets not talk about the lack of information in "percentages" now...) are not interested in eating fewer calories to ensure living longer. In general, the poll respondents did not show overwhelming enthusiasm for an extremely long life; only 27% of women and 40% of men wanted to reach age 120. In that set of people, 44% said they'd be willing to eat one-third fewer calories in order to reach the goal. This means that 44% of 27% of 25% (or 2.97 of every 100) of women polled would consider giving up one-third of calories to live longer (and probably be thinner). Men were 1.5 times more interested. It seems that when offered a golden opportunity, we Americans prefer to pursue happiness in our bag of golden chips.
What people say they want is often quite at odds with their actions. Ask those poor folk pulling their hair out in any corporate marketing department - surveys are a tricky tool.
I'm inclined to think the apparent contradictions stem as much from the manner of asking as the nature of people to do say one thing and do another. Take that quoted poll above, for example. Given the widespread nature of the Tithonus error - the belief that living longer would mean being ever more frail and diseased - asking someone whether he would want to live to 120, providing no further context, is much the same as asking whether he would like to suffer for decades in increasing pain, frailty and disease. Not many takers there. Healthy life extension medicine will mean a longer healthy life; a postponement of disease and frailty by preventing or repairing the root causes of age-related degeneration. Tithonus is a mythical character, and will stay that way.
The success of the "anti-aging" marketplace illustrates that people really do want to be younger for longer. So much so that they are prepared to pull the wool over their own eyes rather than face up to the harsh reality of present day limits to medical technology. People want easy solutions and quick answers right now - but such things don't exist.
Calorie restriction is less popular than it might be because humans have a dreadfully short time preference - the lower regions of our brains value present food far more than the prospect of being alive and healthy decades from now. In effect, we've all evolved to screw the person we're going to be; good now, not so good when you have become that person.
You don't have to let the lower parts of your brain run your life, however. The part of you that is you can ponder much more sophisticated time preference calculations. Look to the future of radical life extension via actuarial escape velocity, and weigh the chances of living into an era in which biotechnology will allow a healthy life of centuries or millennia - an era in which you eat whatever you like, insulated by the same advanced biotechnology that sustains your longevity.