Less is More

 

    "吃七成饱” or translated in English, “Eat 70% full,” is a Chinese eating-related saying that suggests that people should eat less than their full capacity to live a long and healthy life.

 

    In 1935, a rodent study showed that calorie restriction without malnutrition could extend average and maximum lifespan and delay the onset of age-related diseases (1). It was not until the 1990s that calorie restriction became widely accepted as an effective way to delay the aging process.

 

    Various animal studies have tested this “70% full” or “30% less” idea with similar findings. A group of scientists studied the effect of 30% calorie restriction on monkeys (2). 20 years after the study started, monkeys who were fed 30% fewer calories compared to those in the control group not only looked younger, but also their health outcomes were all positive: they had less brain atrophy, muscle mass loss, fat mass, disease conditions including diabetes (actually no diabetes in the restricted group), cancer, and cardiovascular disease; the restricted group also had better glucose and insulin sensitivity when compared to those of the control monkeys.

 

    Besides, the calorie-restricted monkeys lived significantly longer than those in the control group. Of the original total of 76 monkeys, 13% (5/38) of the 30%-calorie-restricted group died of age-related causes which compared to 37% (14/38) of the control monkeys. Survival analysis indicated that at any point in time the control monkeys had 3 times the rate of death from an age-related cause when compared to monkeys under calorie restriction. 

 

    A group of scientists from China did a more recent rodent study on calorie restriction (30% less) (3). They tested rodents in two types of diets (low fat diet-LFD or high fat diet-HFD), and for each type of diet, three test groups which equals to a total of six test groups: 1. Two groups had unlimited food access with no activity equipment in the cage (LFD or HFD), 2. Another two groups were fed 70% of the amount of foods consumed by the unlimited food test groups (LFD calorie restricted-CR or HFD CR) and 3. The last two groups were fed unlimited foods and had the option of exercising on a wheel (LFD exercise-Ex or HFD Ex).

 

    The longest living and healthiest animals were in the LFD CR group. The median and maximum lifespans of the LFD CR group were longer by approximately 20% and 25%, respectively, compared to those of the LFD group. The LFD CR group also exhibited the lowest and most stable body weight and fat content, as well as the best metabolic phenotypes, such as glucose homeostasis and lipid profile at the different ages throughout their lifespan. The HFD group had the shortest lifespan and the worst metabolic phenotypes. Compared with the HFD control group, restricted high-fat diet intake (HFD CR) resulted in dramatic extensions of the median and maximum lifespans (both by 36%), which became similar to those of the LFD and LFD Ex groups. Also, similar metabolic phenotypes were observed. Voluntary running exercise resulted in a significant increase in the median and maximum lifespans (by 13%, and by 18%, respectively) when animals were fed unlimitedly on a high-fat diet but there was no effect on a low-fat diet. The data demonstrate that obesity-related metabolic syndrome is highly associated with accelerated aging and reduced lifespan.

 

    If these rodent lifespan study results are translated to the human diet, then the best option is “70% full” on a low-fat diet, which has the longest and healthiest lifespan; the second-best option will be “full” low-fat diet, or “full” low-fat diet plus exercise, or “70% full” on a high-fat diet; then the next option will be “full” high-fat diet plus exercises, which had 13%-18% longer lifespan than those of the high fat “full” group, which lived the shortest life.

 

    You may expect a better and longer life if you stick to a low-fat diet (high complex carbohydrate diet) with “70% full”. There is wisdom in the old Chinese saying, “eat 70% full,” for better health.

 

    Of course, you may be wondering what is “30% less” or “70% full” of the diet. Each person is different in his or her food preferences and eating habits, and you can use nutrition applications or programs to track your food intake or look up the nutrition facts of your foods to learn how many calories and the nutrition contents of what your current diet contains. You can learn how to do “eat 70% full” and receive advice from a nutrition expert who can help you to make healthy food choices and eating habit changes for achieving optimum health. 

 

    However, the restricted diet needs to be balanced with complete and essential nutrition.  For more information, read my previous blog (https://www.calnutritiongroup.com/post/healthy-aging-nutrition-tips-from-my-102-year-old-grandma) to learn about the basic nutrition factors that ensure a healthy life.

 

References:

1. McCay, C. M., Crowell, M. F. & Maynard, L. A. The effect of retarded growth upon the length of life span and upon the ultimate body size. J. Nutr. 10, 63–79 (1935).

2. Colman, R. J. et al. Caloric restriction delays disease onset and mortality in rhesus monkeys. Science 325, 201–204 (2009).

3. Zhang, C. et al. Structural modulation of gut microbiota in life-long calorie-restricted mice. Nat Commun. 2013;4:2163.