Thursday, March 10, 2011

Giving up on Doggie Weight Loss, Redux

I had started to type this up as another comment under yesterday's post, but decided it deserved its own post.

Credible studies have shown that reducing caloric intake increases life expectancy in mammals. I've wondered about this from time to time, because I am a pretty substantial eater myself. However, I don't like my energy and strength levels when I eat less, and the one study I read on rats indicated that indeed, the rats on the reduced calorie diet didn't do much of anything. They ate so little and moved so little that their metabolisms were slowed, which would explain also, of course, the increased life expectancy.

That doesn't sound like a good quality of life to me, for either a rat, a human, or a dog!

There is also the issue of quality vs. quantity of life, and there is absolutely no doubt that regular exercise increases quality of life. Two of my dogs' brothers were given away as puppies to family friends who raised them as house pets who got little exercise. They started to become geriatric at around age 8. They lost bone density, they became arthritic and hobbly-wobbly; they showed no calamitous signs of poor health, but they showed general signs of aging. The five dogs who remained on the farm and pulled sleds their whole lives, including my girls, continued to look, act, and work like young dogs. Recently, one boy died of a sudden heart attack, but he never lost strength. Another girl has been having seizures, but that has a genetic component that is irrelevant to age. Another boy is still working. And Autumn and Linden are with me, maybe overweight now, but strong and bouncy as puppies. In fact, even folks at our vet's office are surprised when I tell them how old my girls are.

This indicates to me that regular exercise not only keeps us strong and healthy, it also pushes back the age of our physical decline, i.e., it extends our youth and our peak of health. The price of all this exercise, it seems, is that we must eat more, thus speeding up our metabolisms and our rates of cell division, which of course means higher rates of cell mutation and a faster march to the grave.

But that's okay with me. My dogs and I enjoy a rich, fine life. Reducing food intake for the mere sake of extending the length of a life, whose enjoyment is then severely limited by energy levels, is not an option for our personality types. :)

Oh, I set up the tripod last night and failed at both getting good aurora photos and at getting a good photo of the three of us. Oh well. :)


b said...

I never thought about it that way. You would think that exercise is good for longevity. Are you just conjecturing or is there scientific basis for your thoughts. I'm guessing if you were to look up scientific studies, people who live the longest do exercise, but in moderation. And also eat healthy diets, and I definitely remember reading a study on people who have close relationships with family (like in some island in italy and in hiroshima, people have longevity) into their late years due to the close family ties in old age.

Arvay said...

Within the bounds of normal, everyday living, you're right, but *extreme* calorie restriction can push lifetimes to *extreme* lengths. I have no interest whatsoever in that!

Arvay said...

Under the Wikipedia article, "Seventy years ago, McCay CM, et al., discovered that reducing the amount of calories fed to rodents nearly doubled their lifespans. The life extension was varied for each species but on average, there was a 30-40% increase in lifespan in both mice and rats..."

There are actually folks out there who are trying this on themselves. Since attempting this on humans is only a recent phenomenon, even the oldest of these folks is not yet old enough for us to know whether it works on humans, but it seems a reasonable conjecture. But if you ask me to halve my calorie intake, lie around like a beached whale, and in return get to live to be 140, I'd say, no, thank you!