There’s been a lot said about fasting and its benefits in the media of late, in particular the healing it can provide for many troubled with weight-loss issues and endocrine imbalances. Some of the research supporting this is compelling, with even more good news from a recent study regarding its impact on longevity.
According to a study published online in Cell Metabolism, a team of researchers at Harvard University have demonstrated how dietary restriction has the potential to increase a person’s lifespan,
“Although previous work has shown how intermittent fasting can slow aging, we are only beginning to understand the underlying biology,” said William Mair, senior author on the study.
Some of the conclusions of the study were that fasting in this way could improve the overall health of an individual, achieved by the changing activity of mitochondrial networks within cells. The researchers observed that homeostasis in mitochondrial networks was promoted by a restricted diet, which allows for a healthy plasticity between the fused and fragmented states of mitochondria.
“Our work shows how crucial the plasticity of mitochondria networks is for the benefits of fasting. If we lock mitochondria in one state, we completely block the effects of fasting or dietary restriction on longevity,” said Mair.
“Low-energy conditions such as dietary restriction and intermittent fasting have previously been shown to promote healthy aging. Understanding why this is the case is a crucial step toward being able to harness the benefits therapeutically,”said Heather Weir, lead author of the study. “Our findings open up new avenues in the search for therapeutic strategies that will reduce our likelihood of developing age-related diseases as we get older.”
Why does mitochondrial health matter?
Click the button below to read an interview with co-inventor of MitoQ and a leading mitochondria researcher, Mike Murphy, Ph.D. on 'Why Mitochondrial Health Matter's'. He discusses his thoughts on how diet and fasting is important in keeping your mitochondrial health at it's peak.
While research continues on intermittent fasting, it is important to know that intermittent fasting comes in many different forms and is not a one-size-fits-all approach. Some methods require full abstinence of food during fast while others permit small amounts of calorie consumption to get you through the day. Some focus on a time of day to fast while others focus on days of the week you should fast.
Understanding the different methods of fasting and the pros and cons can allow you to find the best method for you, your desired results, and your schedule.
Alternate Day Partial Fast
Alternate day partial fasting refers to a fasting technique where you fast every other day. Rather than a traditional fast, a partial fast allows you to eat food. The fasting days could be classified as more of a calorie restriction than a true fast.
A popular alternate-day partial fast is the 100-25-100 methodology. Essentially, on non-fasting days, you consume 100% of your recommended caloric intake, and on fasting days you consume 25% of your recommended caloric intake. For a typical person, this would mean that fasting days are allotted 500 calories.
An alternate-day partial fast is a popular option for those getting started with a fasting day ideology.
The main benefit of this methodology is that during the fast you are still provided with calories which is less likely to make you irritable.
Additionally, each partial fast day is sandwiched between normal consumption days which can give you the breaks you need to stick with it for longer.
The main con of an alternate-day partial fast is the fasting days. Consuming fewer calories can help your body to reap the benefits of fasting, but some argue it is not as effective in initiating the bodily changes that make fasting beneficial.
Additionally, the 500 calorie allowance can sometimes be difficult to stay on top of. Hunger is one of the strongest motivators for people and with a partial fast, it can be easy to begin eating and get carried away and end up eating much more than you planned. In some ways, a partial fast requires more self-control than a traditional fast where no food is allowed.
Time Restriction Fast
When people first hear about fasting they most likely hear about time restrictive fasting. Unlike day fasts, time restrictive fasts are one of the easiest to implement into a schedule.
In a time-restricted fast, you are allotted a feeding window in which you can eat. After the feeding window, you are required to fast until the next day’s feeding window.
One popular method is the 14/10. The 14/10 method means that you are given a 10 hour feeding period and are required to fast for the other 14 hours in the day. This method is very popular because it requires minimal change to their day to get some of the benefits of fasting. If you are sleeping for 8 hours a night, that means that you only need to shift your eating habits by 4 hours during the day.
Another more intense time-restricted fast is the 16/8 method. Rather than a 10-hour feeding window you are restricted to 8 hours and need to wait a full 16 hours until your next meal. While this method is certainly doable, it can be more difficult to start. Many people will slowly work themselves to these more intense fasts and will sometimes alternate between 14/10 and 16/8.
The largest pro to this method is that it offers people an easy way to get into fasting. Simply set your feeding window and abide by the rules. The fairly ambiguous fasting system offered by a time restrictive fast allows people to fit fasting into their busy schedules.
With the 14/10 method, you can have a relatively normal eating schedule and simply move breakfast to later in the day, move dinner earlier, or a combination. The possibilities are endless and easy to set making it one of the most versatile and utilized fasting methods.
One of the major cons of time-restricted fasting is that those around you are not on the same eating regime as you. The typical breakfast, lunch, and dinner get cut short with time-restricted fasts. So while your time-restricted fast works well during the workweek, when it comes to the weekend and your friends want to go to a fancy dinner later in the evening, you will be forced to either modify your schedule or decline if it is outside of your feeding window.
The 24-hour fast is a more radical approach to fasting. As the name implies, you are required to fast for a full 24-hours. This method is supposed to simulate the eating patterns of early humans where food scarcity could require fasting for extended periods of time.
Unlike a partial fast, the 24-hour fast is a true fast where only water, tea, coffee, and non-caloric supplements can be taken. Many people choose to start a 24-hour fast right after a meal like breakfast. Starting and ending a 24-hour fast with breakfast is a great idea because throughout the day you will most likely not get too hungry and the harder period of time closer to the end of the 24-hours is when you are sleeping.
One of the main benefits of the 24-hour fast is that it is fairly accurate to how our human ancestors consumed food. Some days, people went hungry, and as a diet that aims to resemble how humans ate while being hunter-gatherers, the 24-hour fasting method accomplishes that.
Another pro is that the 24-hour fasts allow you the freedom to eat as you would for more days out of the week. With a 24-hour fast, you should only fast 1-2 times a week. This leaves you with five to six days of unrestricted eating. For foodies that appreciate eating delicious food throughout the week, the 24-hour fast may be a good option to help keep your waistline in check.
One of the largest cons of the 24-hour fast is that you will most likely experience the negative side effects of going without food. Headaches, irritability, and even diminished energy levels may be experienced during this time.
While these typically are short-lived, they can definitely impact your day in a negative way and many people need to plan accordingly to ensure they are not hangry during important work tasks or when spending time with loved ones.
Another con is that during the 24-hour fast you should try to limit overworking yourself. While on a 24-hour fast you are at a severe calorie deficit. If you add working out to that, your body will be at even more of a deficit, which can be very dangerous.
Fasting has quickly become a popular method for people trying to shed some pounds and live a healthier lifestyle. While initially intermittent fasting was met with some skepticism and reservation, many studies like the one from Harvard are providing evidence of the potential benefits of intermittent fasting.
With many different ways to start intermittent fasting, it represents one of the most versatile diets to date. Simply figure out what method works best for you and stick with it to help support your overall wellbeing and mitochondrial health.
Reviewed by: Kai Man Yuen/ BSc., PGDipSci., MSc.