Intermittent Fasting

June brings with it the final week of the month of Ramadan. This is the month in which Muslims fast from all food and drinks from sunrise to sunset. For those living in Melbourne this translates to a fasting time of around 12hrs, and for those who choose to skip the very early breakfast, the fasting time can actually creep up to 20hrs!

This got me thinking about intermittent fasting (IF) and how it might affect our health. A quick google search will produce countless pages claiming that IF will not only help you lose weight but can also offer a range of other health benefits. The question is, do we have the evidence to support these claims?

While more long-term studies are required, the emerging evidence shows that IF is as effective, but not more effective, than standard continuous reduced-energy diets for short-term weight loss. There is some evidence that IF may also improve blood pressure, cholesterol, triglycerides, inflammatory markers and blood sugar and insulin levels, however more research is needed to prove that these benefits are not just secondary to the weight loss.

IF can take a few different forms including time-restricted feeding (daily fasting for minimum 12hrs but more typically 16hrs), alternative day fasting and the 5:2 method whereby energy is restricted to 25% of your usual requirements on 2 non-consecutive days of the week, while eating normally on the remaining 5 days. This can make it a little tricky to compare the research, however there is evidence to show lower rates of drop out in the 5:2 diet as compared with the alternate day fasting and continuous energy restriction. This suggests benefits for long-term weight maintenance.

Dietitians usually warn against any type of diet that promotes any form of extreme restriction. The IF eating pattern has the potential to result in unhealthy eating behaviours such as overeating or even binge eating during the non-fasting time and therefore completely negating the effects of the fasting time. Other unwanted side effects may include increased irritability, fatigue, headaches and loss of concentration. IF is also not for everyone. Children, athletes, pregnant women, people with an eating disorder and those with diabetes should avoid any type of fasting diets.

While IF research is showing promising results, there still isn’t enough evidence to promote it as a superior weight loss method. IF may suit some people but the bottom line is that finding a balanced eating pattern that you enjoy and best suits your lifestyle, is your best bet for achieving long-term health benefits. An Accredited Practicing Dietitian can help you with more tailored nutritional advice and as for IF, more research is needed but it will certainly be an interesting space to watch.