Intermittent fasting. You’ve probably heard of it. You may or may not know what it entails. You may be confused as to what it is. Well, today I will clear things up for you in hopefully the simplest way possible.
Fasting is an in vogue topic of conversation in the current health world. However, done incorrectly, it can lead to a host of health implications.
What it is?
Simply speaking, intermittent fasting is pattern of eating that cycles between a time period of eating and time period without the intake of food.
The act of fasting itself is nothing new to us humans. Certain religions fast during significant periods. Our ancestors likely fasted back when food was not as abundant. We need to fast for certain medical procedures. We fast every day overnight. This is nothing new. However, we have seen a more mainstream shift of this ‘trend’ in recent years.
The types.
There are multiple different types of eating patterns associated with fasting. Generally there is time-restricted fasting as well as alternate-day fasting. I will discuss a few of the main ones below.
16:8 Method
This is a time-restricted fasting pattern that is perhaps one of the most popular. Food consumption is confined to an 8 hour window during the day, with a 16 hour fast. Another similar method by the same principle is the 14:10. Most people following this eating pattern tend to start their food intake at midday and finish consuming their food by 8pm. Hence, their eating is done in an 8 hour window.
5:2 Method
This is an alternate-day fasting pattern that usually involves quantifying foods in calories to ensure a lower calorie intake on alternate days. In most cases calories are restricted to 500-600 calories per day for two days of the week, then on the other 5 days of the week, the individual readopts their normal eating pattern.
24 hours + Method (or the Eat-Stop-Eat Method)
This is a second time-restricted fasting pattern where eating is stopped for a 24 hour window. For example, an individual may also consume clear fluids from dinner on Sunday to dinner on Monday.
What happens when you fast?
When your body is functioning optimally, it is drawing on glucose that is stored in the liver and the muscles as an energy source. However, when the body runs out of glucose (from carbohydrates) as its energy source it then turns to fat stores from the liver. The body breaks down fat into ketones, a process termed ketosis, which are then used as an energy source.
Important to note is how you break your fast. Ensure you consume a balanced plate full of complex carbohydrates, quality protein and healthy fats as well as lots of colour from fresh produce. Breaking your fast with a trip through the drive-thru or with poor quality food is completely counterproductive and can have negative implication for blood sugar balance.
The evidence.
Most of the evidence is based around animal studies (mostly rodents) and there is currently minimal human-based evidence around intermittent fasting.
What are the implications?
One of the main issues with intermittent fasting is that there is always risk of malnutrition, due to a smaller eating window and the potential lack reaching one’s daily recommended intake.
Another issue is ‘overeating’ or binge eating. In some people, they can be so super hungry by the time their eating window opens that they have a tendency to ‘overeat’ or perhaps indulge on the poorer quality foods. In others, ‘skipping’ meals can trigger binge eating and/or an unhealthy relationship with food.
Another issue is flagging energy or blood sugar imbalance. This can be cause for concern in certain individuals with specific health predispositions such as those susceptible to low blood sugar.
Is it for me?
Intermittent fasting should be avoided by women who are pregnant and/or breastfeeding as well as anyone who has a history of disorded eating in any way as fasting can be a trigger in some. Those who suffer from gut issues, chronic illness and/or stress and sleep implications may also want to avoid intermittent fasting too.
For those of you that don’t get hungry in the morning, it may be an okay option, but only if you eat adequate quantities and variety of food at lunch and dinner and a good snack in between, otherwise you may run the risk of being malnourished.
A few last words…
Like most things that get spruiked in the media as the latest health trend, it lacks a lot of evidence and the current human-based research is still quite young. There are a lot of big claims for its benefits, but ethically, as a qualified nutritionist, I can not comfortably recommend this for the majority of the population due to a) the lack of evidence, b) we know that those who eat balanced meals three times daily maintain a healthy weight for a long time too and c) it can cause individuals to develop a fixation on food (healthy or unhealthy).
So, to summarise, if you’re looking at starting intermittent fasting, firstly figure out what your goals are. Why are you wanting to do intermittent fasting? What are you looking at getting from it? Is it a feasible eating pattern for you? Ensure your goals are realistic. Intermittent fasting can be difficult to implement in all routines and much time and preparation should be allocated to ensure a safe yet successful protocol is followed. Lastly, please always check in with a nutritionist or a healthcare provider to help guide you safely.