Calorie Restriction and Longevity

Disclaimer: Please note the following is a discussion about calorie restriction and is not medical or dietary advice of a specific kind. Always consult your doctor or medical practitioner before undertaking a diet or exercise programme.

A healthy and long life is considered a valuable and reasonable aim by many people. Transhumanists take this further and look forward to having life spans in excess of the normal “three score years and ten” (as the old saying used to go) and possibly even greatly in excess of our current average for longevity.

A commonly quoted and easy to grasp method for working towards enhanced longevity is calorie restriction. This is the practice of significantly reducing the amount of calories that a body consumes below that of even a medically recommended level, in the belief that this increases longevity.  This phenomenon is not new and was first noted in ancient times, yet in recent years it has become the focus of increased attention.  Can extending your lifespan happen by markedly cutting down the calories you consume?

It certainly seems the case that for many of us, reducing the amount of calories we consume will be a major step in leading a more healthy life, delaying or preventing the onset of a number of medical conditions. Many of us will be aware that we ought to weigh less and that, alongside exercising, reducing the amount of food we eat and selecting healthier and less fattening eating options is a key way to ensure this. Western societies are facing an obesity crisis due to over consumption and eating the wrong types of food. Tackling this is a practical way for many of us to enhance the chances of a longer, healthier life.



Over the last few years, I have been trying to reduce weight and one of my observations is that you are not aware of just how overweight you are until you start losing weight.  My perception is that many of us are more overweight than we realise or want to admit to ourselves. The Body Mass Index is a useful scale in this regard and many people who might otherwise think they are a normal weight will be surprised to learn that, according to this, they are in fact overweight.

Even losing a modest amount of weight can be beneficial as the body has less strain on it and more energy as a result. Being overweight entails a greater risk of serious medical conditions such as heart problems and diabetes.

This is familiar to most of us and there are a lot of resources of information on the internet on how to lose weight and modify your diet.  The need to lose weight in this well established, familiar context is widely accepted and is a key way for many of us to improve our quality of life, avoid a range of medical conditions and perhaps even ensure a longer, better life.

Calorie restriction goes further than this.  It suggests that significantly reducing the amount of calories, beyond that required for the type of healthy weight loss referred to above, can markedly increase longevity. The degree of reduction in calories is often referred to at least 10% and is on the basis that proper nutrition is maintained, to avoid malnutrition.

The idea is that this substantial reduction in calories will result in a longer lifespan, longer than that arising from the normal healthy lifestyle referred to above. This is based, in part, on medical research carried out on mice and, to a lesser extent, rhesus monkeys. Research in this field suggests there is some basis for this conclusion, but it has proved more difficult to show the same effect in humans.

There are several reasons for this. Humans live longer than both mice and rhesus monkeys and so determining whether a dietary change like calorie reduction will affect longevity requires a long-term study, which will require more commitment and greater expense. With humans, it is much more challenging than it is with mice or monkeys to control factors that may affect the result, such as lifestyle choices. These might be whether or not the subject smokes, the amount or type of exercise they do, stress they are exposed to in their working lives and other extenuating characteristics of this sort.

As more people attempt calorie restriction, the position may become clearer but it is likely to be sometime before the application of calorie restriction in increasing human longevity is established. For the time being, I will be seeking to achieve my goal weight, which entails calorie restriction, albeit of a less startling degree, and once there, look again at this interesting area of research.




Comments