Depending on your intermittent fasting goals, there are possibilities where you can adapt your fasting length. Hopefully, you will find enough informations in this article to make your decision and find the fasting schedule that fits you the best.
Before we start on our journey to fasting, we need to establish the ‘why’.
Why have you decided to fast and what’s going to keep you on track? Once we establish that, we’re then able to play around a little with the ‘when’.
The following reasons are all benefits you could see from fasting:
Although this is by no means an exhaustive list, it covers most angles of why people would choose fasting as a way of life.
Let’s now move on to thinking about our schedule, starting with our very own internal clock – the circadian rhythm.
We’re all born with a built in circadian (daily) rhythm controlled by the part of the brain known as the hypothalamus. Think of the circadian rhythm like a battery charging during sleep and discharging during the wake period and the hypothalamus like the plug that governs the activity.
This body clock is set to approximately 24.2 hours and both light exposure and schedule cues affect the cycle. This means getting out in the morning – experiencing true light of day will affect our whole system. It also means working shifts is going to have an impact on our bodies.
In addition to this there are other factors that disturb our inner clock. Things such as stress, sedentary lifestyles and irregular, unhealthy eating patterns (1).
Recent studies in humans reported that intermittent fasting, results in decreased body weight and fat mass as well as improved blood pressure and insulin sensitivity – especially when feeding time is early or in the middle of the day.
When we restrict the times we eat, the body uses less glucose (sugar) and more lipids (fats) and ketones as energy resources, improving the body’s inner optimal functioning. This whole process also fights against the ageing process and helps repair our DNA by enhancing ketone body levels (indicators for a healthy metabolism).
Taking into account our normal circadian rhythm, it seems that having an early mealtime is the most natural way of eating due to our metabolism being at its most efficient and so we’re able to best utilise ingested food. The late fasting cycle is also able to prevent harmful effects of a nightly high fat diet which has a knock on effect with our sleep.
Exercise and intermittent fasting are simple options that are easy to implement in daily life situations especially if we want to eliminate symptoms of sleep deprivation and other unhealthy lifestyle behaviours but the potential cause of our sleep disturbances may not be solely eliminated by time restricted eating and so rather than treat the symptoms, we need to take a holistic approach (4).
Your diet needs variety to train a flexible metabolism. You need to keep your body guessing in order to keep the ‘goldilocks’ moments. By doing the same exercises day after day, you run the risk of getting bored both mentally and emotionally and so the simple rule is that if something isn’t working, examine the quality and quantity of your activity because the more diverse the activity, the less of it you have to do to put a healthy stress on your body.
Weight can fluctuate daily. If your weight hasn’t budged but you’re feeling more energised, sleeping better and feeling happy, trust the process and stick with it. Don’t let the scale dictate your mood! Having said that, if you’re experiencing a plateau, there are switches you can make to help such as checking your quality of foods or ensuring you’re eating enough (or not too much) of the right foods.
Plateaus are positive when they teach you the best strategy for your unique needs! It takes time to make changes, establish new habits and motivate a sluggish metabolism. We have to trust the process and constantly tweak and repeat (6).
You will eventually find the sweet spot that is right for you. For some people, a sweet spot looks like 16:8, for others it looks like ‘OMAD’ (one meal a day). For you, that may be longer or shorter maybe with a bit of down time when there is a celebration, or at the weekends. A bit of self-doubt along the way is okay – just notice it, acknowledge it and do what you have to do to address those challenges.
Intermittent fasting decreases sex drive in some women, whereas a libido increase with intermittent fasting is experienced by others.
Timing meals with the body's circadian rhythm is beneficial for improving sleep after the first week of intermittent fasting.