Can Intermittent Fasting Lead to Sustained Fitness? We weigh the evidence…

By Zaira Abbas
May 27, 2023

While it’s an undoubtedly popular concept among the more fad-minded in the contemporary health and fitness world, exactly how effective is intermittent fasting when it comes to weight loss and an overall improvement in health? Well, for one thing, it’s certainly easier to manage than you might expect. All it requires is a little self-discipline, though, if you were over-blessed with that you might not be worrying about any excess weight problem in the first place. 


The idea behind intermittent fasting is that, by restricting your food intake, your body will be obliged to deplete its fat reserves to meet your energy requirements. While glucose from carbohydrates is your body’s most direct fuel source, you burn fat to provide energy when glucose isn’t available. Inevitably, this is more likely to happen when your body’s level of food intake is relatively low. 


Essentially, intermittent fasting means scheduling for yourself periods when you refrain from eating. As it is not about what to eat, but only when to eat, it is not considered a diet per se. Although being mindful of what you eat will certainly deliver optimum outcomes, some studies have shown good results are still possible in instances where 14 hours of daily fasting are sustained without changing your normal food choices. 


That aside, let’s briefly consider the five supposed benefits of this particular practice. 


Weight Loss 

Many of those who favour intermittent fasting do so in the belief that it will trigger a hormone reaction that catalyses weight loss. This is based on the notion that lower insulin levels, higher Human Growth Hormone levels and increased amounts of norepinephrine (noradrenaline) will increase the breakdown of body fat and facilitate its use to meet energy needs. 


According to one 2011 study, intermittent fasting also results in less muscle loss than continuous calorie reduction. There have also been claims that it especially benefits those people that don’t have time to devote to meal planning and preparation. This may be why it appeals to those seeking an easy alternative to something more rigorously thought-out and planned. 


Improved Cognitive 

Functioning While the buzz surrounding this practice is relatively new, the notion of intermittent fasting actually dates back many centuries. It was practised by a number of ancient civilisations, with many contemporary religions retaining some vestige of the practice, often in the belief that it helps achieve clarity of focus. In support of this, a study published in Molecular Psychiatry indicated daily fasting can enhance memory and help guard against neurological disorders. 


Fasting is also said to increase the level of a brain hormone called brain-derived neurotrophic factor (BDNF). A BDNF deficiency has been cited as a cause of depression and various other brain problems. Some have even claimed that fasting can help fend off Alzheimer’s Disease, the most common neurodegenerative disease. Such suggestions have, however, yet to achieve widespread acceptance among the medical community. 


Longevity and Slow Ageing 

Another supposed benefit of intermittent fasting is that it can even help you live longer. This is based on the claim that its triggers autophagy, a cellular recycling process that disposes of older and potentially diseased cells, resulting in an extended lifespan. Such assertions are, however, somewhat contentious. 


While there have been some studies that could be seen as lending credence to such a notion, this is a highly controversial medical field and one where commercial imperatives are frequently seen as trumping proper evidential analysis. As ever, it’s best to treat any such claims with a measure of cynicism until an acceptable level of scientific consensus emerges. 


Improved Heart Health 

There have also been a number of assertions that the practice of intermittent fasting can help ward off future coronary problems. As heart disease is both widespread and potentially hugely debilitating (if not fatal) this is an extremely alluring prospect, while again being one that should be treated with a degree of caution until it is comprehensively endorsed by the medical community at large.


Advocates of the notion, meanwhile, maintain that intermittent fasting may improve the body’s insulin response, a mechanism that helps control blood sugar levels. This chimes with the belief that lower cholesterol and blood sugar levels can lower the risk of weight gain and diabetes, two factors known to be related to higher incidences of heart disease.


Prevention of Cancer

Inevitably, given the wide range of benefits attributed to intermittent fasting with varying degrees of credibility, sooner or later some advocate or other was going to champion its anticancer potential. Equally inevitably it was also going to be the ‘sooner’ box that got ticked.


Proponents of this particular belief maintain that intermittent fasting reduces the risk of cancer by slowing the ability of cancer cells to adapt and spread. As a corollary to this, there have also been suggestions that fasting can reduce the side effects of chemotherapy. While not wishing to entirely discredit such notions, it’s worth bearing in mind that the higher the Fear Factor, the greater the likelihood that unverifiable solutions will be posited by the less scrupulous practitioners. Few conditions have a higher fear factor than cancer.