Let’s say you were lost in the middle of nowhere with only a single grain of rice as your last meal. Should you eat the grain of rice and gain the precious little calories it would give you or not eat it, because the calories you gain would not be sufficient enough to cover what it takes to digest the solitary grain?

I have been unable to find a chart displaying the calories in a single grain of rice. I would find the amount of calories myself, but I do not have the right equipment for the experiment. The single grain of rice is a plain white rice.

Thank you legatissimo for your help.

The only some-what reliable information I found was an uncooked short japannese grain with 14% saturation=0.025g
I think that the 10% digestion is unrealistic because there should be a minimum opperation cost. It is like starting your car. No matter how far you plan to go, a certain amount is used to get it started.

Here's an interesting article about caloric-restricted diets. It's relatively germane.

NTY:

How depressing, how utterly unjust, to be the one in your social circle who is aging least gracefully.

Jim Wilson/The New York Times
Mike Linksvayer, 36, on a low-calorie diet for six years, is 6 feet and 135 pounds, and his blood pressure is 112 over 63.
In a laboratory at the Wisconsin National Primate Research Center, Matthias is learning about time’s caprice the hard way. At 28, getting on for a rhesus monkey, Matthias is losing his hair, lugging a paunch and getting a face full of wrinkles.

Yet in the cage next to his, gleefully hooting at strangers, one of Matthias’s lab mates, Rudy, is the picture of monkey vitality, although he is slightly older. Thin and feisty, Rudy stops grooming his smooth coat just long enough to pirouette toward a proffered piece of fruit.

Tempted with the same treat, Matthias rises wearily and extends a frail hand. “You can really see the difference,” said Dr. Ricki Colman, an associate scientist at the center who cares for the animals.

What a visitor cannot see may be even more interesting. As a result of a simple lifestyle intervention, Rudy and primates like him seem poised to live very long, very vital lives.

This approach, called calorie restriction, involves eating about 30 percent fewer calories than normal while still getting adequate amounts of vitamins, minerals and other nutrients. Aside from direct genetic manipulation, calorie restriction is the only strategy known to extend life consistently in a variety of animal species.

How this drastic diet affects the body has been the subject of intense research. Recently, the effort has begun to bear fruit, producing a steady stream of studies indicating that the rate of aging is plastic, not fixed, and that it can be manipulated.

In the last year, calorie-restricted diets have been shown in various animals to affect molecular pathways likely to be involved in the progression of Alzheimer’s disease, diabetes, heart disease, Parkinson’s disease and cancer. Earlier this year, researchers studying dietary effects on humans went so far as to claim that calorie restriction may be more effective than exercise at preventing age-related diseases.

Monkeys like Rudy seem to be proving the thesis. Recent tests show that the animals on restricted diets, including Canto and Eeyore, two other rhesus monkeys at the primate research center, are in indisputably better health as they near old age than Matthias and other normally fed lab mates like Owen and Johann. The average lifespan for laboratory monkeys is 27.

The findings cast doubt on long-held scientific and cultural beliefs regarding the inevitability of the body’s decline. They also suggest that other interventions, which include new drugs, may retard aging even if the diet itself should prove ineffective in humans. One leading candidate, a newly synthesized form of resveratrol — an antioxidant present in large amounts in red wine — is already being tested in patients. It may eventually be the first of a new class of anti-aging drugs. Extrapolating from recent animal findings, Dr. Richard A. Miller, a pathologist at the University of Michigan, estimated that a pill mimicking the effects of calorie restriction might increase human life span to about 112 healthy years, with the occasional senior living until 140, though some experts view that projection as overly optimistic.

According to a report by the Rand Corporation, such a drug would be among the most cost-effective breakthroughs possible in medicine, providing Americans more healthy years at less expense (an estimated $8,800 a year) than new cancer vaccines or stroke treatments.

“The effects are global, so calorie restriction has the potential to help us identify anti-aging mechanisms throughout the body,” said Richard Weindruch, a gerontologist at the University of Wisconsin who directs research on the monkeys.

Many scientists regard the study of life extension, once just a reliable plotline in science fiction, as a national priority. The number of Americans 65 and older will double in the next 25 years to about 72 million, according to government census data. By then, seniors will account for nearly 20 percent of the population, up from just 12 percent in 2003.

There's more!!