By Fiona Wing – Naturopath
Recently, you may have seen or heard about the popularity of fasting and the many benefits that come with it. Some of us fast for its reported benefits on healthy aging and metabolic processes, others for weight loss, others for detoxification or religious purposes. It has become quite a popular addition to the dietary routines of many of us and, as it has risen in popularity,many researchers have cast an eye over its practices and positive effects on health.
If you have been thinking about giving it a try, it is vital that you speak with a Healthcare Practitioner such as a Nutritionist beforehand to make sure that dietary changes such as fasting are right for you. Not everybody will experience the same effects, and just like weight loss programs, fasting programs can be tailored to suit your individual needs to ensure that you get the most out of the changes you are making.
Fasting is defined as “periods of voluntary abstinence from food and drink” and can take on many forms. Some types include Modified Fasting, Alternate Day Fasting, and Time Restricted Feeding (daily fasting intervals of between 12 – 18 hours).
One of the most popular types, and one that you may have heard of, is a Modified Fasting Regime developed by Dr Michael Mosley called the 5:2 or “Fast Diet”. This diet sees you consuming around 1200 – 1500 or more calories for five days of the week (depending upon your individual needs) and then dropping that down to between 500-600 calories for two days a week (again, depending upon your individual needs).
Alternate day fasting is a more strict form of fasting because you are required to fast very second day. It is similar to the 5:2 diet in your calorie consumption (1200-1500 on your feeding days and 500-600 on your fasting days), however, you fast every second day – not just for two days each week.
Time Restricted Feeding sees you restricting your calorie intake to zero for a certain number of hours in a 24 hour period, and then consuming your normal caloric load – which can be different for each individual (eg: 1200-2000) in the remaining hours. Usually, the fasting period lasts for around 18 hours with a large proportion of those hours being sleep time (to avoid much of the hunger!). You may eat between say 12pm and 6pm and fast for the rest of the 24 hour period.
Fasting diets have seen a rise in popularity amongst Australians, with its followers reporting improvements in weight management, mental clarity, energy, sleep habits and bowel regularity. These reported benefits are now being backed up by research. A recent review performed on both human and animal studies into the effects of fasting, has highlighted the benefits of fasting for our overall health. Not only did the subjects experience moderate weight loss, the researchers also found that it supported healthy levels of cardiovascular health markers such as HDL and LDL cholesterol; sugar regulatory markers such as insulin; and inflammatory markers such as C-reactive protein. The review found that fasting may also have positive effects on mood and fatigue.
Another reason to see a healthcare practitioner before you start to incorporate fasting into your lifestyle, is to get your blood levels of some of these markers tested. After a few months fasting, it would be interesting to get them re-tested to get a before and after comparison and see if any changes have been made to your health.
There is a large amount of variability within each type of fasting diet, and, as mentioned previously each diet can be tailored to suit your dietary preferences, activity levels and lifestyle. The number of hours of fasting, the number of days per week fasting (2-7), the actual days per week fasting (Monday and Thursday; Monday, Wednesday and Friday; every day), the times of day during which you decide to fast and the number of calories you consume can all be modified to suit your individual needs. What’s more, the benefits to your health can be very positive.
Patterson, R. et. al. “Intermittent Fasting and Human
Metabolic Health” J Acad Nutr Diet 2015