Everyone benefits from cutting calories, from yeast to rats and humans. Several experiments have shown that in less complex organisms, restricting calories can double or even triple lifespan.
Though no such link has been established for humans, some people such as members of the Calorie Restriction Society International cut their calorie intake by 25 per cent or more in hopes of living longer. This diet limits calories without scrimping on vitamins and minerals. While skeptics such as me are convinced that living in denial just makes life appear longer, researchers claim otherwise.
In a review article in the April 16 edition of Science, nutrition and longevity, researchers at the Washington University School of Medicine in St. Louis, University College in London and the Andrus Gerontology Center at the University of Southern California, report that calorie restriction influences the same handful of molecular pathways related to ageing.
Cutting back between 10- 50 per cent calories decreases the activity of pathways involving insulin-like growth factor (IGF-1), glucose and TOR (target of rapamycin), and increases lifespan in animals.
More interestingly, they found that that calorie restriction promotes good health, with animals on a frugal diet developing far fewer age-related diseases such as cancer, cardiovascular disease and memory problems. One in three animals on calorie restriction died at an advanced age without developing any age-related diseases. Ninety-four per cent of those on a normal diet died of one or more chronic diseases.
Researchers hope the new findings can develop medicines that influence pathways affected by calorie restriction and help keep people healthy as they get older.
Statistics, however, show most people are guilty of gluttony. One billion adults are overweight and more than 300 million obese. Without action, this number will surpass 1.5 billion by 2015, estimates the World Health Organisation (WHO).
Globally, over 42 million children under five years of age are overweight and at a higher risk of developing diabetes and heart diseases at a younger age. About 44 per cent of diabetes, 23 per cent of ischaemic heart disease and 7–41 per cent of certain cancers are linked with overweight and obesity, says the WHO.
Eating a healthy diet coupled with at least 30 minutes of regular, moderate-intensity physical activity reduces the risk of obesity, heart disease and many other diseases.
It’s unlikely that the frugal diet fad will catch on, more so because there are serious side effects. Calorie restriction lowers testosterone levels and reduces libido. That apart, a low-cal diet slows metabolism and lowers the core body temperature. That’s enough trouble to cool down humanity’s response to the frugal diet fad.