The term Intermittent Fasting (IF) has been around since 2012, although fasting of various types has been around since at least 5th century BC or longer and is regularly performed by many religions.
The term IF means that we fast for a certain period of time each day eg. we eat in a particular timeframe window (7am-3pm) or we have days where we eat less than other days eg 5:2 (two days of the week only 500 calories gets consumed).
There are various ways you can do IF, which can make it a little easier. The idea is that if you follow the time frame version, you go without food for 16-18 hours (usually overnight). Once you have been fasting for a 12 hour window you will start to get value as this is technically when your body goes into a fasted state, although the 16-18 hour window shows more health benefits. Therefore, you then only eat during the remaining 8 hour window during the day. Studies have shown that eating earlier in the day has more advantage such as 7am-3pm compared with later in the day such as 11am-7pm (although this still will achieve results).
Most of the studies and information on IF has come from how it works with men’s bodies and their hormones. Some women can’t tolerate it or can’t tolerate the longer fast of 16-18 hours. Start with 8-12 hours and see how you go. If you wake up really hungry or stressed, then listen to your body and eat. See how your body goes increasing these fast times or move the fast time to different times of day and see what works best for you:
- 7am-3pm (optimal from studies carried out)
- 2pm-10pm – only if you go to bed later (although not ideal)
- 6pm-2am – only if you are a night shift worker
IF works much better eating along with the body’s circadian rhythm and only eating during daylight hours.
Addressing stress, anxiety, sleep and some severe gut issues is a must before starting IF.
What are the health benefits?
- Weight loss without feeling hungry – Between meals (no snacking), our insulin levels go down and fat cells can then release their stored sugar, to be used as energy. We lose weight if we let our insulin levels go down. The entire idea of IF is to allow the insulin levels to go down far enough and for long enough that we burn off our fat. This increases your ability to become fat adapted (your body burning fat for fuels instead of carbs);
- Improves blood sugar balance by increasing insulin and leptin sensitivity which then in turn decreases metabolic and diabetes risk plus the risk of heart disease;
- Reduces inflammation and helps to fight free radical damage;
- Reduces cortisol if it’s suited to your body type – some people will have an increase in cortisol first thing in the morning to get the body going after a long fast, so it may not be a suitable method of eating for some (especially women);
- Supports and improves healthy gut function and gut bacteria – Having a break from eating is optimal for healthy digestive function. If we are bombarding it with food non-stop, it doesn’t get the chance to break things down and take it’s time to do what it has to do. A good amount of time between eating is 3-4 hours to really let that meal be digested. Fasting at night while you are sleeping is the best time to do so, especially when it comes to gut health. At night we go into what is called “rest and digest” and we certainly don’t want to be interrupting this time with food. Starting your fast at least 2 hours before you go to bed is optimal (if you can’t do the earlier fast times) to ensure you are not in the early stages of digestion when you hit the pillow;
- Improves brain function;
- Can boost athletic performance;
- Due to all of the above it can increase energy levels and lengthen your lifespan.
There are a number of health conditions that it is thought to help with that include:
- Weight loss resistance and obesity
- Insulin resistance/pre-diabetes
- Joint inflammation such as arthritis
- Fatty liver disease
- Brain fog
- Gut issues, especially IBS/SIBO
- PCOS (Polycystic Ovarian Syndrome)
Intermittent fasting is not for everyone. Some people shouldn’t do intermittent fasting such as:
- Pregnant and breastfeeding women;
- Children and teenagers;
- Some health conditions eg type 1 diabetics can do this, but should work with a health care professional to ensure hypoglycaemia doesn’t become a problem. Some people with thyroid conditions may also not tolerate this lifestyle choice;
- Those with a history of eating disorders as it could initiate a relapse;
- Some people just know when they try it that they are not suited to doing IF and that is OK.
What do you eat if you are doing IF?
Obviously if you are eating highly processed convenience “junk” foods and drinks IF is not going to have great effect. You don’t have to restrict calories (unless you choose the 5:2 option) when doing time frame IF. But you do have to ensure you are eating healthy. Good protein and fats are crucial, especially when you break your fast eg breakfast (at whatever time of day that is). Avoiding sugar and refined grains is a must. Eating whole foods such as fruit, vegetables, legumes, wholegrains, protein and good fats is recommended. Drinking lots of filtered water is a must.
You don’t need to do IF every single day to get results either. A few times a week can valuable.
If you aren’t up to doing IF, then at the very least try not to snack – unless you really have to have something to eat. Just eat 3 main meals a day and have at least that 2 hour window of no eating before bed.
I personally do intermittent fasting of around 12-14 hour fast most days. My body likes this timeframe and I have seen some great benefits. I listen to my body and know the longer fast time of 16-18 hours is not suitable for me. But if I wake up really hungry and can’t possibly face the day, then I eat which is usually at least 8 hours after my last meal. Most nights I finish eating for the day by around 6pm only having a cup of chamomile tea before bed.
If you would like guidance and more personalised advice on IF, then contact me to book in a consult – email@example.com or 0417 679 287.
*I am not a fan of extended fasts or water fasting and feel this definitely needs a health professional’s guidance.
References available upon request
Megan Crockart is a qualified Holistic Nutritionist & a self-confessed foodie! Megan has a special interest in working with individuals with allergies, food intolerances, SIBO, eczema, pre- & post-natal health & children’s health.
To book a consultation with Megan please click here.