Intermittent Fasting: Life-Changing Benefits of Just Another Fad?

Kate Brooks
Oct 17, 2024
9 min read

Hormonal changes in midlife are certain for all of us, and especially for those of us who are female. Perimenopause and menopause can be particularly challenging due to the significant physical and mental health changes that often occur during these times. This explains why focusing on exercise and nutrition as self-care strategies becomes so important to many people. It is also common for people to tell me that things they used to do, no longer works the same.

In my own case, whilst I’ve not personally been prone to weight gain, (ok, I’ll be honest as a Personal Trainer, it is definitely a bit easier to keep fit!), I’ve found that now heading into my late forties; despite my day-to-day role, it is much easier to get a bit tubby, and less straightforward to maintain athletic running weight for my own fitness as well as generally feeling good.

My First Experience with Intermittent Fasting

So, from a sense of curiosity after reading about the compelling benefits of intermittent fasting. I decided it was about time I gave intermittent fasting a try myself! Could it actually be as easy as just delaying breakfast and ensuring a 12 to 20-hour eating window?

Would the experience, of waiting seventeen hours between eating and breaking my fast, to initiate the process of Autophagy (aka cellular clearance); be comfortable or agonising? Would it frankly be worth it - or not really?

The Simplicity of Delaying Breakfast: Is It That Easy?

So, I’d read lots, and more recently was very excited by Dr. Mindy Pelz’s book, “Fast Like a Girl”. I’d long been aware of how I was eating, particularly focusing on the nutrient density of my food, the amount of fibre I was eating, and being generally totally determined to square the circle of making meals both nutritious and delicious. Even those I know close to me who are a times a bit sceptical, admit their tastebuds and preferences have gradually shifted and aside from occasional treats, preferences then tend to settle around healthier eating.

I’ve also in the past been a big advocate of tracking macronutrients (commonly referred to as macros) and found the relative proportions of fats, protein and carbohydrates in the diet were good to be aware of.

How Fasting Changed My Perception of Health

So intermittent fasting was something I previously thought might just be a tool for improving self-discipline, and perhaps also not really worth it if your body composition is already good. However, I started to change my mind when I understood the broadness of the mechanisms and systems that were positively impacted by intermittent fasting for improved health and longevity-related outcomes. So, I decided it was time to get some first-hand experience of how it works, not only for myself but also to help others.

This blog is my own reflection on that and attempts to delve a little deeper into why you might want to try intermittent fasting yourself and what benefits it offers as a lifestyle habit. I have focused on a few key areas in relation to midlife health and fitness optimisation, including Liver health and hormones; metabolism, anti-ageing and of course the microbiome.

The topic of the microbiome in particular has become very big, since the Covid pandemic, which helped highlight the idea of all immune supporting strategies. The understanding we now have of the microbiome, aka, these bacteria that live within our bodies; their interactions and importance, has I think helped us collectively see why we need to look after our microbiome in order to be healthier ourselves.

What is Intermittent Fasting? A Focus on When, Not What, You Eat

So, to begin this topic with real intent, what we first need to ask is, “How might we define Intermittent fasting?”

Intermittent fasting (IF) isn’t about restricting specific foods, but about when you eat. It involves alternating periods of eating and fasting, sometimes this is done for health motives and other times part of religious and cultural traditions. It is worth saying intermittent fasting is not dieting. Unlike diets that focus on what you eat, intermittent fasting focuses just on when you eat. This distinction is crucial because it shifts the focus from calorie restriction to metabolic health and overall well-being.

Dieting vs. Intermittent Fasting: Two Distinct Approaches

Many diets fail because they are restrictive, which can be unsustainable in the long term. Intermittent fasting, on the other hand, can be easily adapted to different lifestyles and does not necessarily require giving up your favourite foods. Instead, it promotes a healthier relationship with food by encouraging mindful eating during eating windows and allowing the body to rest and repair during fasting periods.

The Importance of Liver Health During Fasting: Reset and Restore

Let’s begin with the Liver. This organ is responsible for eliminating toxins and processing insulin, amongst other things, and by having an overnight fast of over twelve hours has a sufficient break to help it reset and work at its best.

Doing the opposite of a long overnight fast would be to eat late at night and then again early in the morning. Whilst your liver can usually handle it; as we get older, or come into peri-menopause, the strain that fluctuating hormones can place on the liver in addition to a poor diet or the timing of our food intake, increases the risk of non-alcoholic fatty liver disease, (NAFLD).

Metabolic Flexibility, The Growth Hormone and Muscle Mass

Other symptoms related to menopause are also likely to become worse if our liver is not working optimally. Skin issues, hot flushes, fatigue, mood swings and brain fog have all been connected to reduced liver function, so the simple act of expanding the time overnight during which you do not eat is extremely health protective.

Ideally, when the liver works well, we have balanced blood sugars low inflammation levels, and after twelve hours or longer we switch from using glucose for energy to fat. This is called metabolic switching or metabolic flexibility. In turn, this switch also triggers the production of human growth hormone, which also helps to protect our muscle mass and so as we burn fat for energy but maintain muscle mass, we improve our body composition as well as facilitate a healthy balance in relation to good and bad cholesterol levels.

Increasing muscle mass also increases the energy our bodies need on an ongoing basis, and therefore further helps with blood sugar balance and reduces fat storage as the muscle-to-fat ratio increases still further in a virtuous cycle. I’m not talking about body-building levels of muscle mass, but enough so that you can lift heavy things and enjoy an active lifestyle for as long as possible is definitely a great goal.

Why Increasing Muscle Mass is Vital for Long-Term Health

On a slight aside, it is a good idea to periodically weigh yourself and check in on how much energy you need, as a common pitfall for women particularly is to eat too little causing the metabolism to slow as well as insufficient energy to be present to build muscle, and it also causes significant stress. So, whilst a fast triggers various positive processes including metabolic flexibility, it is important to bear in mind there is a balance to be struck, and times, when particularly for women a break from intermittent fasting is also advisable. Dr Mindy Pelz’s book (see references) explains more, extremely adeptly and is very accessible. A recommended read if you would like to know more.

If you would like to know more about your own metabolism, I have a separate resource on this available called “Nutrition for optimising midlife and beyond” available on request and soon to be via download at www.katebrooksfitness.com

So, returning to metabolic switching or metabolic flexibility, this has also been shown to improve the function of the energy centres of our cells; our mitochondria! Their efficiency is critical for overall health and as we age, mitochondrial function typically declines, contributing to the ageing process and various age-related diseases.

Autophagy: The Cellular Clearance Process that Boosts Skin and Energy

A slightly longer intermittent fast (thought to be seventeen hours and longer) triggers a further important process to take place on a cellular level. This is a process called Autophagy which is the scientific word that describes cellular clearance.

Autophagy is a completely natural process which has some amazing benefits for the skin and your body's cells. The process elevates hormones that increase collagen which helps maintain youthful-looking skin and prevent wrinkles, something I am definitely not immune from being increasingly interested in.

How Fasting Helps Your Gut Microbiome and Reduces Inflammation

However, the benefits to our mitochondria the energy powerhouses of our cells are also pretty compelling. As we age, mitochondria typically decline in number and succumb to damage, which autophagy can help repair and by doing so, not only reduces the risk of the development of disease(s) but also facilitates how much energy we have by optimising the number of channels through which energy can be converted.

So impressive stuff, and if looking healthy and young, having more energy and protecting yourself from disease already is not enough to convince you of the virtues of intermittent fasting? What about the impact this can have on the gut microbiome?

Fasting and Brain Health: The Role of BDNF in Cognitive Function

Proven to be an essential feedback mechanism for many of the areas we have already touched on, and certainly a site of reinforcement of the benefits already discussed. It is perhaps fairly obvious that what we eat is important but what is new is that it has been shown that intermittent fasting boosts the numbers of beneficial bacteria. There are many interactions being uncovered but the healing of inflammation, reduction of bloating and reduced autoimmune reactivity and propensity towards leaky gut is seriously impressive. Resulting in increased effectiveness of our immune system as well as our mood and overall well-being.

If this were not enough a longer fast of over seventeen hours that prompts autophagy also causes the release of a protein called BDNF that maintains the health and growth of our brains. It is almost as if our bodies were designed to go without food for short periods of time, and certainly, when we look at the multitude of benefits it is hard to come to any other conclusion.

Certainly, while eating too much or at least more pertinently, eating too frequently! (it is definitely for most of us a temptation, particularly when feeling tired), learning of all these benefits and protective effects on our future selves is what I find quite inspiring, and I do intermittent fasting regularly for 16 hours 3 times a week now. For slightly longer once a week or every other week depending on my schedule. After all, food is fuel, and it depends on my goals.

So, is it worth trying? Having done my research into the benefits, noticed a definite reduction in my own wobble level (specifically around the middle), and increased definition at the same time; AND felt increased energy and vitality and not found it too hard, I would definitely recommend considering if intermittent fasting could be helpful for you, so here are some tips if you would like to give it a try and are not sure how to start.

Practical Tips for Incorporating Intermittent Fasting in Mid-Life

Always bear in mind it is essential to do so in a way that supports your health and well-being and consult your doctor or health professional if you have any questions, but it doesn’t need to be daunting especially if you…

Start Slowly: If you’re new to fasting, begin with a 12-hour fasting window (e.g., 8 PM to 8 AM) and gradually increase it to 14 or 16 hours as your body adapts.
Stay Hydrated: Drink plenty of water, herbal teas, or black coffee during fasting periods to stay hydrated and support detoxification.
Focus on Nutrient-Dense Foods: When you do eat, focus on wholefoods, nutrient-dense foods that provide the vitamins and minerals your body needs to thrive, a healthy balanced diet is an essential accompaniment to successful outcomes from intermittent fasting.
Listen to Your Body: Pay attention to how your body feels during fasting and be sensible about when you give it a try, for example not before a very long or hard workout, unless you want to risk losing muscle mass. If you experience dizziness, extreme fatigue, or other concerning symptoms, consult with a healthcare professional and obviously don’t do it! These effects are most likely in a small minority, but important that I highlight it is not possible for absolutely everyone all of the time.
Combine Fasting with Exercise: Intermittent fasting is not intended to be a way of not doing exercise, even though it is a powerful way to look and feel healthy. Exercise seriously enhances the benefits of intermittent fasting. Include strength training and cardiovascular workouts alongside anything else you enjoy whether, yoga, running or rowing.
Be Consistent: Consistency is key to reaping the long-term benefits of intermittent fasting. Find a fasting schedule that fits your lifestyle and stick with it. I’ve found Dr Mindy Pelz’s book ‘Fast Like a Girl’ an invaluable resource and extremely helpful in relation to avoiding stressing the female body unnecessarily at certain times of the monthly cycle. It still has relevant content for male readers in relation to the scientific explanations of the benefits of IF and this can be extremely important in relation to being motivated and committed to any new routine.

Thanks for reading, please share or let me know if you enjoyed this blog and what other topics you might like me to cover.

e-mail: Kate@katebrooksfitness.com

Please Note: This article is a personal perspective, for information only. I am a Personal Trainer. I do offer nutritional advice and have long been a keen health advocate, I also do my research; but so should you.

References:

Brady, 2015 “Liver disease in menopause” 2015, July, Pub Med.
Zoe.com, Chmielewska, 2024, “Can intermittent fasting improve your gut health”?
Dr Mindy Pelz, Fast Like a Girl
Time restricted eating for the prevention and management of metabolic diseases, Endocrine Reviews, Vol 43, I2, Manoogian, Chow, Taub, Laferrere & Panda, 2022.
The Conversation, Bennion, Wegman and Guo “ Feast then Famine’ 2015 – How our cells respond to Oxidative Stress.
MyMT (Menopause Transformation) by Dr Wendy Sweet (PhD) www.mymenopausetransformation.com