Fasting your way to health- could intermittent fasting be the way forward for longevity and good health?
To conclude our mini-series, this final guest blog from Juleyka will focus on sustainability specifically towards you as an individual. A lifestyle change that could work for you depending on your current health levels and lifestyle circumstances. Intermittent fasting (I.M) has recently garnered a lot of research in recent years, it is one of the health interventions that is well tolerated and has lots of promising research behind it.
A lot of recent research has also been linking it to how I.M can contribute to reduction of non-communicable disease (such as obesity/diabetes/digestive disorders) .Therefore also it also contributes to achieving the all-important Sustainable Development Goals (specifically SGD3,good health and wellbeing ) which we initially touched up on part 1 of the mini-series .
So, what exactly is intermittent fasting?
There are several types of intermittent fasting, however with each type, the main principle is that you alternate between periods of eating and not eating. See below for some variations of I.M.
- Time restricted eating-this tends to be the most popular approach and one that is in line with your natural circadian rhythm. The 16/8hr guideline is one approach- this means you eat within an 8hr window, for example 9-5pm (an average working day) and then 5pm to 9am the next morning you omit eating any meals, but are encouraged to drink, weather that be water or herbal teas.
- 5:2 fasting – this method involves sticking to your usual eating pattern 5 days a week, then 2 days out of the week you can reduce your calories between 500-800 calories. Again, this is quite a flexible approach.
- Alternate fasting, like 5;2 but with a more flexible approach, you alternate between days of eating the way you usually eat and then select other days during the week where you reduce your food consumption or completely fast.
What are some of the benefits for the gut?
The research to date has listed a plethora of benefits from intermittent fasting. One of which is that I.M has shown to increase gut bacteria diversity. Research has shown that individuals had increased levels of beneficial gut bacteria such as Faecalibacterium, Roseburia and Akkermansia. The latter is particularly important for maintaining healthy gut lining levels. In fact, it can thrive even during fasting because it feeds on the mucins present in the mucus layer of the gut lining. Once it digests the mucin, SFA’s (short chain fatty acids) are released.
These SFA’s are used as an energy source by surrounding gut bacteria and provide a whole host of benefits which include mucus production, intestinal barrier integrity, and protection against inflammation as well as the reduction of the risk of colorectal cancer.
Moreover, having good levels Faecalibacterium has also been shown to be particularly important with COVID recovery, research has shown that people with low levels of this bacteria were associated with a more severe level of COVID response. For more information on this, click here.
Some other health benefits of intermittent fasting:
- Improves blood glucose levels, insulin sensitivity and promotes weight loss-This reduces your risk of diabetes and other metabolic diseases. Particularly if you undertake the night-time restricted eating, you are at lower risk. This is because excessive night-time eating has been linked with obesity and diabetes.
- Reduce systemic inflammation and have a role in the prevention and treatment of chronic disease- A systematic review and metanalysis (which is deemed as one of the gold standards of research in the science ) has shown I.M significantly reduced inflammation markers such as C-reactive protein (CRP).This marker is present in many chronic inflammatory diseases and is linked to many conditions .This highlights the potential of I.M as an additional way to manage and treat such inflammatory conditions.
- Better brain health and working memory- a study on participants who voluntarily fasted during the month of Ramadan showed just under 30 days there was an increase of another beneficial bacteria: the Lachnospiraceae, together with other Clostridiales. These bacteria are main sources of creating another SFA called Butyric acid. Research has shown microbiota-generated butyrate, which means butyrate produced in the gut, is well established to encourage metabolic benefits via gut–brain neural circuits. In short, this improves brain function and cognition.
How do I know if intermittent fasting is for me?
Although robust, longitudinal research is still in growing in this field; the current academia behind this subject is very promising and has shown lots of exciting benefits already. However,everyone is different and depending on your health goals and your current state of health, you will be able to gauge weather I.M is for you. It is important to note that intermittent fasting may not be for everyone and can even be associated with some risk for certain people. For example:
- Children, pregnant, lactating women, diabetic, underweight or those at risk of an eating disorder.
As with any health change, please consult with your doctor before undertaking any dietary changes in your life.
Some practical take aways:
- The research has shown that aligning eating time with body’s internal clock with body’s internal clocks improves metabolism. Reduce night-time eating as much as possible if your schedule allows to do so, eat your last meal as early on the day as possible.
- If the 16/8hr rule seems too difficult, perhaps consider a simpler for of intermittent fasting which is in line with your lifestyle and easiest for you to sustain. Perhaps you could start off with reducing the level of snacking in between meals and then slowly, with the guidance of a health professional, build up to intermittent fasting.
- During the hours that you are consuming food, try adding more fibre. Remember it is the consumption of the fibre which helps the increase of the all-important SFA’S which also linked with enhanced brain function. For more info on how you can increase your levels click here to see our plant point cheat sheet and why we love fibre.
- Some people love breakfast or snack in between meals and may struggle with this regimented approach. There are many other ways such as simply opting for a well-balanced diet, weather that be a flexitarian diet or one that just encourages more varied fruit, vegetables, fibres, and protein sources. Remember, the key is that it is sustainable and enjoyable for you.
The key principle is that it fits to your personality and lifestyle, if you love to eat and don’t like restriction, there are many other ways to improve your health as we have outlined above. Anything that is easy to sustain will make it easier to maintain long term, and long-term habit changes are the key to good health and wellbeing.
Weather that be through intermittent fasting or even just simply increasing the levels of nutrient dense foods in your diet. There is no one size fits all when it comes to making healthy changes. However, the one principle that does show success is that it is sustainable for you, and if it’s for the environment too, then even better.
Juleyka is a nutritionist from Manchester; she is passionate about food sustainability in relation to health and nutrition. She has partnered with dissertations for good contributing to research around the U.N Sustainable Development Goals and food sustainability practices, volunteered for Dimension's charity; creating meal plans for people with complex needs. More recently, she has also joined with YouGen as a content writer on the link between sustainability and health.
Sources:Is Intermittent Fasting Sustainable? | Columbia University Irving Medical Centre
Intermittent fasting: eating by the clock for health and exercise performance | BMJ Open Sport & Exercise Medicine
Remodelling of the gut microbiome during Ramadan-associated intermittent fasting | The American Journal of Clinical Nutrition | Oxford Academic (oup.com)
Microbial Metabolic Networks at the Mucus Layer Lead to Diet-Independent Butyrate and Vitamin B12 Production by Intestinal Symbionts (asm.org)
Early Time-Restricted Feeding Improves Insulin Sensitivity, Blood Pressure, and Oxidative Stress Even without Weight Loss in Men with Prediabetes - ScienceDirect
Gut microbiota modulation as a possible mediating mechanism for fasting-induced alleviation of metabolic complications: a systematic review - PMC (nih.gov)
Frontiers | The Role of Short-Chain Fatty Acids From Gut Microbiota in Gut-Brain Communication | Endocrinology (frontiersin.org)
Effects of intermittent fasting diets on plasma concentrations of inflammatory biomarkers: A systematic review and meta-analysis of randomized controlled trials - PubMed (nih.gov)