As you are reading these lines, there are probably as many diets as there are people who practice them. Some can be odd and even dangerous, while others can provide tremendous health benefits.
Therefore, it is totally understandable to lose track of the do’s and don’ts, even when you are making all the efforts in the world to educate yourself. Blogs, social networks, mobile apps, documentaries… it can easily become a never-ending puzzle!
Fasting has been a practice rooted in many religions for millennia. It is also often seen as a way to purify the body and mind. In recent years, science has been studying the virtues of this practice.
So unless you've been living under a rock for the past few years, you've probably heard of intermittent fasting (IF). I mean, it does represent every dieter’s dreams: no calorie or food restriction, eating and drinking basically anything you want since there is no specific food to eat or avoid, as long as you do it within your time window.
For example, a fast lasting 16 to 20 hours leaves 4 to 8 hours to consume one to two meals and possibly snacks. What is important to understand is that there is a crucial distinction between fasting and starving yourself, and if you ignore it, you could damage your health and immune system.
Prized by some and hated by others, this eating habit approach is the subject of much discussion within the health and fitness community. Therefore, the debate is inevitable: is intermittent fasting a recommended practice to achieve fitness and weight management goals, or should we rather stay away from it?
There is currently no consensus on the matter, and expert opinions are divided, which leaves a lot of room for self-interpretation. While more research is needed to throw light on the question, let’s clarify who can safely practice intermittent fasting and who should perhaps reconsider opting for other ways to improve their eating habits.
Children and adolescents who decide to fast could increase the risk of slowed growth and delayed puberty (1). It is advised only to try intermittent fasting if you are a fully grown-up adult.
Because intermittent fasting prevents you from eating for an extensive period of time, it could be harmful to anyone suffering from chronic diseases like high blood pressure, heart failure, lung diseases and arthritis or to those taking medications (2). If it’s not the case and your health is top-notch, then you should be good to give it a try!
Being self-aware of the clues your body sends you is a huge part of the process. You could experience symptoms like headaches, lethargy, crankiness and constipation and ignoring them for too long could lead to more severe complications.
If you aren’t sure where to start, remember that it is always better to try a shorter fasting period and longer eating window, like 16-8 or even 14-10, until your body and mind can fully adjust to your new eating habits. We wrote an article about chosing a fasting plan as a beginner, click here to read it.
IF is generally considered to be less restrictive and much more flexible since there is no calorie restriction. Besides, it can easily fit into any lifestyle (vegetarian, plant-based, religious restrictions, etc.). The sky is the limit!
Any pregnant woman who wishes to fast, whether for intermittent, therapeutic or religious purposes, must always warn her obstetrician or gynecologist before starting.
This is necessary to make sure that she does not present any contraindication and doesn’t endanger herself or the baby. Pregnancy usually requires specific nutritional needs, and talking with your healthcare provider is an essential step before deciding to integrate intermittent fasting into your lifestyle (3).
In general, breast milk’s nutritional composition is affected only by famine or severe malnutrition cases. Since the composition of breast milk is greatly influenced by certain factors such as your diet, body nutrient storage and hormone levels, sufficient food in terms of quantity and quality as well as good hydration is essential at all times.
However, this can be difficult for breastfeeding moms who are fasting regularly, and as a result, their milk supply may decrease.
Because diabetes management requires careful consumption of carbohydrates, IF should only be done under qualified healthcare providers’ supervision (4). Adequate medication management during fasting, as well as blood sugar monitoring, is necessary in order to avoid blood sugar deviations (5).
The older we get, the weaker our immune system becomes. This, unfortunately, makes us more prone to infections and diseases, which will often require medication treatment. One of the biggest risks associated with IF consuming less food than the daily energy requirements because of your time-restricted eating schedule.
Elderly people would have to be extremely vigilant and careful to time their medication with their IF schedule. It is therefore advised to tell your doctor if you’re planning on starting intermittent fasting while taking prescribed medicines.
With intermittent fasting, you may see a tendency to eat larger portion sizes since you have been waiting to eat for too long. Studies have shown these habits could increase the risk of developing eating disorders such as anorexia or bulimia.
You could be wondering if you should be fasting or not when having your periods. The short answer is yes, but some of us should make some modification in order to make it more acceptable for our bodies. We wrote a full article about wether you should fast or not while having your periods.
Keep in mind that, even if you tick one of these boxes right above, it doesn’t mean intermittent fasting is completely out of reach. You might still be able to benefit from its practice, but definitely need to seek medical advice from a professional who will take all of your health parameters into consideration.
Before starting an intermittent fasting diet, experts recommend talking with a doctor or dietitian. The most important thing is to listen to your body and eat in the way that is best for you.
You might also be interested in reading our article "Should I fast daily ?".
Intermittent fasting can lower risk factors of breast cancer. Learn more about how intermittent fasting can help to prevent breast cancer.
There are many different intermittent fasting schedules. Read this to find out the differences between each one.