As a holistic nutritionist, I am constantly reading to keep abreast of the latest science in nutrition, health and wellness. I have been focusing on fasting recently. Many of my clients are concerned about metabolic issues such as too much weight around the middle, elevated blood sugar, high triglycerides and so on. As there is compelling evidence that fasting is an effective way to remedy these issues, I took a deep dive, fasting forward into February.
Throughout January, I binged on fasting, gobbling up every word of several books, articles and studies. And as I never recommend anything to my clients that I haven’t done myself (so I can better understand and support their efforts), I also did a month of twice-weekly 24-hour fasts. My lucky husband was part of this experiment as well! On Mondays and Wednesdays, we did not eat until 24 hours after we had finished eating dinner the night before. So after my month of feasting on the research and fasting from food, this is just a brief look into the fascinating world of fasting …
It’s much easier than you think 🙂
I will start out by saying that it is much easier than you think. On Mondays, in particular, I actually welcomed it (since, like most folks, we tend to indulge on weekends more so than during the rest of the week). Also, in doing a dinner-to-dinner fast, the vast majority of your non-eating hours are while you are sleeping. There are a few other reasons, from a lifestyle perspective, to recommend it as well. And these also handily overcome the usual objections I get from clients when I suggest dietary changes:
- fasting is simple,
- it doesn’t require any work (no preparation, shopping, cooking or clean up),
- fasting frees up time and
- it saves you money!
What’s not to like? I can hear you say “but I’ll starve”! No, you won’t. I will give some tips about how to manage any hunger pangs later on. And if my formerly “hangry” hubby can handle it, frankly, anyone can. But first, here’s why you might want to give fasting a whirl …
Fringe benefits of fasting beyond weight loss …
Fasting definitely induces weight loss, which is its main attraction for many. But it is important to note that fasting has many other benefits and these are just a few:
- fasting reduces body fat, with harmful excess visceral fat (in and around the liver and other abdominal organs) the first to go
- it lowers insulin levels, improves insulin sensitivity and helps regulate blood sugar,
- fasting slows ageing and
- it boosts your energy and brainpower!
Again, what’s not to like? So how does it do all these things?
Fasting lowers insulin
If you read my previous blog post with the Fasting Mimicking Menu, you’ll know that insulin is the hormone needed to move the sugar that comes from the food you eat from your blood and into your cells where it is used for energy. All foods stimulate the release of insulin. So when you are fasting, there is no insulin release because you aren’t eating any food. You will also know that insulin directs the storage of excess sugar (first, as glycogen in the liver and, second, as body fat) to regulate blood sugar levels.
Evidence points to obesity being less the result of calories-in exceeding calories-out than due to hormonal imbalances involving insulin. Insulin drives fat production and obesity is found where insulin is both high and persistently high. Indeed, clinicians have found that increasing the amount of insulin taken by Type 2 diabetics leads to significant weight gain.
If we drink sugary beverages and/or eat sugary foods and highly processed carbohydrates (think white rice, bread, pasta, cakes and so on), the body must release a great deal of insulin to deal with the influx of readily absorbed sugar (insulin is high). If we eat these foods consistently throughout the day as meals and between-meal or late-night snacks, then insulin is persistently high.
This can get to the point that the body stops “listening” to insulin (aka insulin resistance), resulting in the body producing more and more insulin to have the same effect (ever higher and more persistent levels of insulin). This gives rise to the development of fat, including harmful excess visceral (or belly) fat, and leads to obesity over time. And this weight proves quite stubborn to lose. Why is that?
When your fridge is full, you never fetch food from your freezer
Thank Jason Fung, MD and author of The Complete Guide to Fasting, for this analogy, which is both apt and intuitive. As I mentioned earlier, insulin directs the storage of excess sugar. After the cells have what they need to function, excess sugar is stored first in the liver, as glycogen. Think of this as storing fresh food in your fridge. This food is easily accessible and can be used at a moment’s notice when you need energy. Anything that doesn’t fit in the fridge, or is meant for use much later on, is stored in the freezer. Think of body fat as your freezer. As long as your fridge is always full, you never fetch food from your freezer! And as long as you are eating regularly throughout the day, you are keeping that fridge full.
If you restrict your food intake but still spread it throughout the day, you still have some food in your fridge, and your body just switches to using only a little of it at a time to make it last (this is why caloric restriction can often lead to slower body metabolism). But if you let your fridge become empty, then your body goes into the freezer for the energy it needs, and starts burning the fat. Fasting helps burn fat because it empties the fridge! And as eating food stimulates insulin, not eating food (fasting) lowers it. And this (in a simplified nutshell) is how fasting helps to reduce body fat, lower insulin, and improve insulin sensitivity and blood sugar regulation.
Fasting slows ageing
Here I am going to get a teeny bit technical and talk about autophagy. The word autophagy is derived from Greek and roughly translates as “to self-eat”. It refers to the process by which the body breaks down its old cellular components and builds them anew. It is a process of self-regeneration and self-renewal. The accumulation of old cellular parts may be responsible for many of the effects of ageing.
Energy from food is required to sustain our cells and their component parts. When the body senses that readily available energy is limited, the body must prioritize how this energy may best be used. In doing so, it will “weed out” the oldest, least functional and least efficient cellular components and break them down for recycling and re-use.
Key to note here is that the body is sensing readily available energy. To revisit our earlier analogy, this is the food in your fridge (glycogen) not your freezer (fat). Eating (even small amounts of food) keeps filling the fridge and can suppress autophagy. Why bother breaking down the old stuff if there is abundant energy for everything? When we eat multiple meals and snack mindlessly throughout the day and late into the night, we limit the amount of time that autophagy is working to regenerate our cells and ourselves. Autophagy is more active when we are fasting, increasing repair and restoration – and slowing ageing. Magic!
Fasting boosts energy and brainpower
To keep this blog post brief(er), I won’t delve into the physiological responses to fasting that are thought to boost energy and brainpower. [Hint: one involves fasting’s effect on brain-derived neurotrophic factor, which supports both neuronal growth and long-term memory.] I find the evolutionary explanation rather compelling, however. Consider what must have happened when our ancestors ran out of food and got hungry. Those that remained alert and had the mental acuity and energy to find more food survived. Those that did not would have starved to death. Ultimately, natural selection favoured those of our ancestors whose physiology had adapted to become more active and cognitively sharp in the face of hunger. And that is why fasting tends to make us more productive. Not to mention more blood gets to our brain and muscles as less is needed by our digestive systems!
Fasting isn’t for everyone…some caveats
Marvellous as this all sounds, fasting is absolutely NOT recommended in certain circumstances.
Do not fast if you:
- are underweight or malnourished
- have an eating disorder or other unhealthy relationship with food
- are pregnant or breastfeeding
- are younger than 18
Be sure to obtain the advice and assent of a health-care professional before fasting if you:
- have Type I or Type II diabetes
- take any medications
- have gout
- suffer from gastroesophageal reflux disease (GERD)
Gung ho to give it a go? Here is my #1 fasting tip:
Fluids are your best friends, for several reasons:
- They fill you up and distend your stomach. This sends signals to the brain which activate the perception of satiety. It is one of the ways your body regulates your intake of food.
- When you are not eating food, you are also not eating salt, so your body tends to release water. You will need fluids to stay properly hydrated. This is why bone broth is recommended on fasting days, as the broth contains salt and other electrolytes to help maintain hydration. Be sure to use a high quality, organic bone broth (avoid the supermarket tetra-paks full of food additives). Your local butcher likely stocks one or, better yet, make your own. Download my Fasting Mimicking Menu for February for a delicious bone broth recipe.
- They stimulate your taste buds so you don’t get bored. A bored person quickly becomes a person who wants to eat! Mix it up – hot, cold, fizzy, flat, with and without caffeine, savoury, citrusy or fruity (just avoid sweet)!
I start my day with a glass of water followed by mushroom coffee (weird, I know, but a discussion of medicinal mushrooms is a whole other blog post). Caffeine helps with appetite suppression (though I suggest avoiding caffeinated drinks after noon or they may affect your sleep). I froth it up with an Aerolatte and sprinkle cinnamon on top (also an appetite suppressant). It feels like I’m having a proper latte!
Then I have some matcha green tea, followed by one of a plethora of herbal tea I have on hand. Water infused with citrus, mint and/or cucumber is another good option. When “lunch” rolls around, it is time for bone broth. Serving it in a bowl and eating it with a spoon makes it feel like more of a meal.
My afternoon treat is a fizzy kombucha (a fermented tea beverage). This Pear, Ginger & Chamomile flavour made by Toronto’s Alchemy Pickle Company is a favourite of mine and only 30 calories and 3 g of sugar per 250 ml (less if you cut it with soda water like I do). Always check the nutrition label before buying kombucha as there are some brands that are very high in sugar. Also be sure you purchase kombucha that contains live probiotics (i.e. has not been pasteurized). [BTW, kombucha makes a great base for cocktails on non-fasting days as it is much lower in sugar, not to mention more interesting, than most traditional mixers]. Fizzy drinks are fab as the bubbles help fill you up as well. And mineral waters have the added benefit of providing electrolyte-balancing minerals and salts. Before you know it, it’s dinner time!
Other fasting tips
- Stay busy – as I said earlier, a bored person quickly becomes a person who wants to eat.
- Fast on work days as you are generally busier. I also find that on fasting days my mind is clearer and I am very energetic. Combined with not needing to take the time to prepare and eat food, you will find you are much more productive! And you may find it easier to avoid social meals during a working day (depending on your line of work, of course).
- When hunger pangs hit, remember my #1 tip: fluids are your best friends! If you feel hunger pangs coming on, slowly drink some water or tea or coffee and it will pass. And if you work from home like I do, DO NOT make anything in your slow cooker for dinner, as the aroma of delicious food cooking all day will drive you to distraction. For the same reason, avoid being in restaurants or anywhere yummy food is being prepared (see next tip). Why torture yourself?
- Choose a fasting regimen that works for you. And it doesn’t have to be the same each week. You are more likely to stick to fasting if you fit it into your lifestyle, not the other way around. If a social event or work lunch comes up on a day you normally fast, simply change your fasting regimen to another day that week. I’ve decided to continue with my 24-hour fasts on Mondays and on Wednesdays I eat all my food between noon and 8. On other days, I aim to fit all my eating into a 10-hour window. This means that I am fasting a minimum of 14 hours every day.
- Do not use it as an excuse to binge on other days. During my month of fasting, I found I became more satisfied with proper serving sizes on non-fasting days. I was more in tune with my appetite and better at distinguishing hunger from dehydration or boredom. Eating a nutritious diet of whole, unprocessed foods with sufficient protein, fat and fibre also keeps you satisfied and your blood sugar well-regulated, making you less likely to binge.
- Work up to it. You might find it easier to start by restricting your window of eating. First, try not eating again until 12 hours after you last ate (and by that I mean the last time you ate anything, not your last full meal). Then make that window larger, hour by hour.
Before you know it, you will find that fasting for 24 hours is (forgive the metaphor) a piece of cake!