By Brian W. Donnelly, M.D., Pediatric Alliance — North Hills Division



Annie Sneed considers an enlightening perspective in BioEssays entitled “Why do the well-fed die young?”

Nematode worms, fruit flies, mice and other lab animals live longer, healthier lives when they eat less than they otherwise would if more food were available. Primates may also benefit, and perhaps humans—which is why research funds are pouring into this phenomenon.


There are 2 reasons I like this article.

The first is the headline of Sneed’s article.  Occasionally, the headline does not do the article justice.  But this time, it does transmit a worthy message: eating less increases life span.

Can you read this??
Underfed animals rarely develop cancer and heart disease.

In case you didn’t know, public health problem #1 in the USA is overeating.  Overeating leads to being overweight, developing hypertension, diabetes mellitus, vascular disease, and some kinds of cancer.
So… this headline is a beauty!

Now, in fairness to my grandmother, who told me to clean my plate, there ARE health downsides to being undernourished.  The trick is to eat enough;  not too much, not too little.  It’s a ‘just right’ thing — just ask Goldilocks!

The other reason I like this article is how it challenges the old theory about hard times leading to lower reproductive rates in animals, across the board.  I was never fully comfortable with this one.  Sure, survival must come first.  Reproduction is something of a luxury, relatively speaking.  But, the bigger the brain, the less controlling this theory becomes.

The take home lesson is this: the cerebral cortex overrides any presumed evolutionary pressures.  Women in China are currently pressured to have only one offspring.  Women in Muslim countries are currently pressured to have as many babies as they are biologically able to have.  Women in America have babies whenever they please …  or, sometimes, whenever their chosen contraceptive approach fails.  These cultural pressures supercede any alleged evolutionary pressures.

Evolutionary theories may apply to nematodes, fruit flies, and mice.  But creatures that have gyri (and souls) need to check their evolutionary rules at the door.

(Dr. Margo Adler presents an illustrated explanation of “Why do the well-fed die young?” on YouTube.)


More PediaBlog posts from Dr. Donnelly here.