In the 1930s, a Cornell University professor of nutrition, Dr. Clive McCay, confirmed that caloric restriction in rodents extends life expectancy by up to 50%–the equivalent of 150 years in humans!(1) This kind of experiment has now been repeated across many species with similar results. Current studies at the National Institute on Aging show the same early adaptations in primates on low-calorie diets as other species. Eating less seems to generate fewer free radicals, thus lessening potential damage to cellular machinery like DNA and mitochondria.
Are there human examples of this phenomenon? Finding long- lived populations has been hampered by the lack of reliable age verification data which tends toward age exaggeration and false conclusions. However, Okinawans have what reliably appears to be the largest concentration of centenarians, about 35/100,000 compared to 7/100,000 in the US. This group seems to be remarkably healthy, and differ markedly from Okinawan emigrants in Brazil and the US who have high coronary heart disease and cancer rates.
After 25 years of studying Okinawan centenarians, some clues are surfacing about their dietary habits: a low-calorie, low-fat, plant-based, complex carbohydrate-rich diet is the key to maximizing life expectancy and minimizing risk of the debilitating diseases of aging.(2)
One of the most frequent New Years resolutions people make is to lose weight. This is often very appropriate after the indulgences of the holiday season! Too often we equate celebration with foods that are high in calories and in generous amounts. Perhaps we need to follow the example of Okinawans who practice “hara hachi bu”.
This Okinawan characteristic means you stop eating when you are 80% full! The stomach stretch receptors take about 20 minutes to tell us we are full after a meal. So, if we stop at 80% we will likely be satisfied 20 minutes later. Okinawans eat 10-40% few calories than Americans. Serving sizes are about one half of those in the US, too!
We might all be better off if we consistently started practicing “hara hachi bu”!