Caloric Restriction: The Key Towards Anti-ageing?

Queenie Woo, HK BioTek Intern

As the saying goes, it is better to keep yourself "seventy percent full" at every meal. In reality, a moderate diet can not only maintain your figure, but is also beneficial to health. Caloric Restriction, also known as Energy Restriction, is defined as a reduction in energy intake below the amount that would be consumed ad libitum while maintaining adequate intake of essential nutrients including water, carbohydrates, protein, lipids, vitamins, and minerals.

So far, several animal experiments have confirmed that restricting calorie intake can effectively prolong the lifespan of mice, yeast, worms, and even primates such as monkeys. Studies reported caloric restriction can reduce the rate of cancer and prevent the occurrence of age-related diseases. According to the latest experiment conducted on humans, consuming 15% less calories per day based on energy requirements for two years can slow down the body's metabolic rate, reduce oxidative stress and oxidative damages to cells and tissues. In the meantime, weight and body fat of the participants have also decreased, as well as their cholesterol, blood pressure and blood glucose levels. The status of inflammation in experimental subjects have also been ameliorated within two years, which helps to reduce the risk of chronic diseases.

During the process of metabolism, the human body produces energy, where mitochondria release by-products named reactive oxygen species (ROS). The generated ROS will accumulate in the body and cause oxidative damage to cells and DNA. Scientific researchers believe the accumulation of oxidative stress and oxidative damage is the culprit of aging-related diseases such as atherosclerosis, cancer, and diabetes. Therefore, calorie restriction is expected to be a viable and promising method to extend human lifespan and improve health status.

Despite current experiments done on humans have shown that calorie restriction does not cause any adverse effect on the human body, this diet still requires decades to confirm its long-term effects on the human body and to validate its effectiveness on anti-aging. It is important to note that calorie restriction is not the same as dieting. Inappropriate calorie restriction can result in health problems such as hypotension, irregular menstruation, osteoporosis, and cause cognitive impairment. In view of this, if you adopt caloric restriction, it is crucial to ensure you are under an optimal nutritional status. One should always have adequate absorption of essential nutrients, and consume nutrition supplements if needed. Regular exercise during caloric restriction is also advocated to maintain bone health.

References:

1. https://www.thelancet.com/journals/landia/article/PIIS2213-8587(19)30151-2/fulltext

2. https://pubmed.ncbi.nlm.nih.gov/32940695/

3. https://cn.nytimes.com/health/20190719/cutting-300-calories-a-day-shows-health-benefits/zh-hant/