Fasting is one of the oldest methods for maintaining a healthy body and mind. In today's climate of dieting and counting calories, our good friend fasting has been forgotten. Recent studies show that alternate day fasting does not only help reduce fat, but it's also beneficial for many areas of your health, and may even increase longevity. Sounds good to us.
Fasting is not new. Fasting has it's roots in all the oldest religions - Buddhism, Islam, Chritstianity, Hinduism, Taoism - but it's purpose is not so much for losing weight, but rather as a way to show devotion, discipline, and for the religions that practice meditation and yoga, it was a way to clear the mind. Evidently, our ancestors understood the benefits of fasting as an aid to physical and mental improvement.
Today, many people still fast during religious holidays (the most well-known being Ramadan), but many others also use it to supplement a healthy diet. However, in the mainstream perspective, fasting is somewhat extreme. The preferred method for weightloss today is dieting, or counting calories. But if fasting was a valued ancient practice used for millennia by many different peoples, surely they were onto something, right?
Recently, the largest study of it's kind was undertaken by researchers at the University of Graz in Austria. The research recruited 60 healthy adults with a normal weight to undergo alternate day fasting (ADF), which requires subjects to eat every other day, leading to 36 hour periods of fasting followed by 12 hours of unrestricted eating. While half the group followed this regimen, the other half could eat whatever they wanted for four weeks.
The ADF group could drink as much water, tea and non-caloric drinks as they needed to. They underwent continuous glucose monitoring to ensure that they did not take in any calories on fasting days, and also filled in a food diary. Other than coming into the research facility periodocally, the participants lived their normal, everyday lives.
The researchers found that when the ADF group ate during the unrestricted 12 hours, they didn't make up for all of the calories lost during fasting, and generally lost around 7.7 lb over the four weeks.
Furthermore, they observed a number of health benefits that were not found in the other group, including longevity biomarkers such as lowered levels of triiodothyronine (a thyroid hormone), sICAM-1 (these represent inflammation associated with ageing), reduced cholesterol levels, a downregulation of amino acid methionine (a restriction of this showed lifespan extension in rodents), a continuous increase of ketones (which means your body is using it's fat as a source of energy), and a reduction of lipotoxic android trunk fat mass, or belly fat.
A second group of 30 people undertook ADF over a period of six months. Previously, it was suggested that a long-term reduction of caloroic intake could have negative health effects, including declines in bone mineral density and white blood cell counts. However, the six month ADF group showed no signs of these negative effects, suggesting that this weightloss strategy may be more beneficial than other weightloss methods like dieting or counting calories.
Although the health benefits are many, the researchers of the study do not recommend this strategy for everyone. "We feel that it is a good regime for some months for obese people to cut weight, or it might even be a useful clinical intervention in diseases driven by inflammation," Madeo said. "However, further research is needed before it can be applied in daily practice. Additionally, we advise people not to fast if they have a viral infection, because the immune system probably requires immediate energy to fight viruses. Hence, it is important to consult a doctor before any harsh dietary regime is undertaken."
In the future, the researchers plan to undertake the ADF study with obese and diabetic people, as well as people with other dietary needs. But until those studies come out, if you're not obese or severely underweight, undertaking alternate day fasting could be an excellent way to lose some weight, improve your body's health, and clear your mind. Check out a guide to alternate day fasting, make sure to not push your body past it's limits, and enjoy!