For many people the fountain of youth is something that they have always dreamed about. Slower aging and living a longer life is something that many would pay exorbitant amounts for, but there is a lot of research to say that simply eating less food could lead to longer and healthier life. This is the basic principle behind what is known as calorie restriction.
What is Calorie Restriction?
At this point, a lot of you may be thinking that a calorie restriction diet simply means not stuffing your face to the point of obesity. However, this is not the case. It actually involves the long term reduction of calorie intake by around 10% or more compared to the average diet, without causing malnutrition. A lot of research has been performed in this field over the recent years, especially with animal models, and the results have been promising.
Calorie Restriction Benefits
There are some obvious benefits with calorie restriction. Because you are eating far less than average, you are essentially eliminating all the problems caused by overeating, including obesity and diseases linked to obesity. One study looking at differences between long term (6 years) practitioners of the calorie restriction diet and healthy individuals on a normal diet found some significant differences. Calorie restricted individuals had 15.3% less body fat, lower levels of bad LDL cholesterol, triglycerides, and blood pressure, while levels of good HDL cholesterol were higher compared to non-restricted individuals. The authors of this study therefore concluded that calorie restricted diets appeared to have a strongly protective effect against atherosclerosis (a major cause of heart attack and stroke) (Fontana et al, 2004). These benefits should really not come as a surprise, since it's fairly logical to expect that eating less will lead to better overall health, especially in a society that has become notorious for obesity.
What is far more interesting about calorie restriction is its potential effect in extending life and slow the aging process. Of course this concept is difficult to prove with human subjects, especially since there are many external variables that must be considered. Instead, such studies are often performed on animals such as rodents and non-human privates in a lab setting. This phenomenon was documented in the scientific literature as early as 1935, where it was observed that calorie restriction resulted in lab rats living up to twice as long as non-restricted animals (McCay et al, 1935). In a more recent publication, closer to home, calorie restricted diets were investigated in monkeys. In this study, it was reported that 80% of the monkeys on calorie restricted diets were still alive at 20 years, compared to only 50% of non-restricted animals (Colman et al, 2009).
Calorie Restriction Negatives
Although it is quite clear that calorie restriction can improve general health, and has the potential to extend life and slow aging, it does have one major obvious downside for bodybuilders and athletes. Calorie restriction has been shown to reduce muscle size as well as strength (Weiss et al, 2008). It may be possible to limit the amount of muscle loss through training and dietary intervention. It has been recommended that high protein diets, especially that including the leucine BCAA, as well as creatine supplementation may be helpful in preserving muscle mass (Morley et al, 2010).
Starting calorie restriction for younger individuals as well as the elderly is not recommended. At these ages, commencing calorie restriction may result in increased mortality (Morley et al, 2010). It is therefore recommended that calorie restriction should only commence at adulthood. It can then be maintained indefinitely from there on, even into old age. However, it should not start at old age.
If you are considering taking on a calorie restriction diet, just keep in mind that the key benefit is achieved through a lifetime commitment. Unlike other diets where you can cycle on and off, the potential life extending qualities have only been observed in those practising the diet over the long term. For bodybuilders, this means that switching from cutting to bulking phases will be out of the question. It also means that providing a calorie surplus for building large amounts of muscle will be extremely difficult. Calorie restriction diets may therefore not be ideal for active bodybuilders. However, for other people, there are definitely some attractive benefits associated with calorie restriction. In such cases, it is important for them to maintain existing muscle mass by weight training, and applying good nutrition and incorporating supplements such as whey protein, BCAAs, and creatine.
Colman et al (2009), Caloric restriction delays disease onset and mortality in rhesus monkeys. Science, 325: 201-204
Fontana et al (2004), Long-term calorie restriction is highly effective in reducing the risk for atherosclerosis in humans. PNAS, 101: 6659-6663
McCay et al (1935), The effect of retarded growth upon the length of life span and upon the ultimate body size, J. Nutr, 10: 63-79
Morley et al (2010), Antiaging, longevity and calorie restriction. Current Opinion in Clinical Nutrition and Metabolic Care, 13: 40-45
Weiss et al (2008), Caloricrestriction but not exercise-induced reductions in fat mass decrease plasma triiodothyronine concentrations: a randomized controlled trial. Rejuvenation Res, 11: 605- 609