In the health and wellness space, few trends have captured the imagination as much as intermittent fasting (IF). This is a rare example of where modern medicine and science are catching up with an ancient tradition rooted in many cultures throughout the world. Whilst a lot of the attention is around the weight-loss benefits, intermittent fasting is so much more than just a diet. For its followers, it is a way of life with the potential to transform our minds, bodies and even lifespans. But for all the hype, what exactly is intermittent fasting and how can it benefit you? In this post we’ll explore the actual science and evidence behind intermittent fasting and how healthy it really is. We’ll also review the different types of intermittent fasting and how to do it properly.
What is Intermittent Fasting?
Intermittent fasting involves cycling between periods of eating and prolonged fasting. It doesn’t dictate specific foods to eat but rather focuses on when you should eat them. This practice isn’t exactly new and it echoes ancient fasting traditions and eating patterns. What is new is that this method of eating has gained attention due to scientific research showing its wide array of benefits. There are countless studies showing that intermittent fasting can help with weight loss and improve metabolic health. Some evidence even suggests it may reverse ageing and extend lifespan. However, as with all things in life, nothing is easy and there’s no such thing as a silver bullet. The benefits depend on a number of factors. These include the fasting periods, the type of IF, your feeding window and your own genetic and lifestyle factors.
What are the Benefits of Intermittent Fasting?
Intermittent fasting can impact every cell and molecular system in your body, which is why it has such a wide range of health benefits. Here are some of the best-known ones:
- Weight Loss: This is probably what sparked recent interest in IF. By limiting the eating window, intermittent fasting naturally reduces calorie intake, which causes weight loss. Fasting periods can also affect the hormones that influence our weight. For example, insulin levels reduce during fasting, which results in more fat burning.
- Improved Metabolic Health: Intermittent fasting can have a positive impact on your metabolism. This includes lower blood sugar levels, cholesterol and blood pressure. This often leads to a lower risk of type 2 diabetes and other metabolic diseases.
- Heart Health: Some studies suggest that intermittent fasting may benefit heart health. It does so by reducing important risk factors like blood pressure, cholesterol levels, triglycerides and inflammation.
- Brain Health: Intermittent fasting is believed to benefit brain health and may even help protect against neurodegenerative diseases. It can boost the release of brain-derived neurotrophic factor (BDNF), a protein that plays a role in memory and learning.
- Cellular Repair and Autophagy: During fasting periods, cells trigger an advanced waste removal process called autophagy. This helps break down and get rid of broken and dysfunctional cellular components. Autophagy is vital for cellular maintenance and protection against various diseases, including cancer and Alzheimer’s disease.
- Longevity: There’s emerging evidence suggesting that intermittent fasting could lead to a longer life in animals. However, more research is needed to confirm this benefit in humans.
- Reduced Inflammation and Oxidative Stress: Intermittent fasting can reduce inflammation and oxidative stress in the body. Both of these are linked to ageing and many chronic diseases.
- Improved Digestive Health: By shortening feeding windows, intermittent fasting can give the digestive system a break. This can help improve gut health and digestive issues.
- Enhanced Physical Performance: Many people report higher energy levels and better physical performance while fasting. This is possibly due to the metabolic shift from using glucose to fatty acids and ketones as a primary energy source.
- Mental Clarity and Concentration: Another key benefit of intermittent fasting is that it may increase mental alertness and improve concentration. This occurs during the fasting periods.
How Does Intermittent Fasting Work?
All types of intermittent fasting involve alternating cycles of eating and fasting that trigger a series of physiological changes in the body. These changes impact various bodily functions and systems. This includes insulin levels dropping to facilitate fat burning and human growth hormone levels increasing. Additionally, cellular repair processes like autophagy are activated. Altogether, these lead to the numerous benefits linked to intermittent fasting. Below is a breakdown of how it works.
- Alteration of Eating Patterns: During the fasting phase, your body uses up its sugar stores and starts burning fat. The eating phase provides nutrients and energy, which are stored for use during the fasting periods. This is known as metabolic switching, and it matters because it improves insulin sensitivity and energy efficiency, boosts fat burning and supports cell health.
- Changing Energy Sources: When you eat, your body uses glucose from the carbohydrates in your food as its primary energy source. During fasting, when glucose isn’t readily available, it begins breaking down stored fat for energy in a process known as lipolysis. This shift from glucose to fat can help with weight loss and improve metabolic efficiency.
- Hormonal Adjustments: Eating causes insulin levels to rise, which helps glucose get absorbed into the cells. During fasting, insulin levels drop significantly, which encourages fat burning and reduces the risk of type 2 diabetes. Fasting can also raise human growth hormone and stimulate the release of norepinephrine (noradrenaline), a neurotransmitter that enhances fat breakdown. Together, these changes support muscle gain and fat burning.
- Cellular and Molecular Changes: Intermittent fasting activates autophagy, a process where cells remove damaged components to allow regeneration and efficient function. This is beneficial for cellular maintenance and longevity. Fasting also influences changes in gene expression linked to disease protection and a longer lifespan.
What are the Different Types of Intermittent Fasting?
There are various different types of intermittent fasting. Although these are very different in terms of approach and schedule, they all aim to unlock the metabolic and cellular benefits of intermittent fasting. Spend a little time understanding these different types so you can choose the one that best fits your lifestyle and goals.
- The 16/8 Method (or Leangains Protocol): This is probably the most popular type. You fast for 16 hours each day and restrict eating to an 8-hour window, so you might eat between 12 pm and 8 pm and fast overnight until midday. It’s relatively easy and flexible because you’re essentially skipping breakfast or dinner, and it tends to be more sustainable than full-day fasting. The trade-offs are morning hunger if you’re used to breakfast, the odd social meal falling outside your window and a temptation to overeat once the window opens.
- The 5:2 Diet (or Fast Diet): Here you eat normally for five days and reduce your intake to around 500 to 600 calories on two non-consecutive days. It only asks for restriction on two days a week, you can choose which days suit your schedule and you still get benefits without fasting every day. The downsides are stronger hunger on the low-calorie days, possible dips in energy if they clash with busy days and the need to plan carefully so you still get enough nutrients.
- Eat-Stop-Eat: This involves a full 24-hour fast once or twice a week, for example from dinner one day until dinner the next, with normal eating in between. It’s simple, it can create a meaningful calorie deficit and you can pick which days to fast. The catch is that full-day fasts feel daunting for beginners, they can disrupt social meals and there’s a real temptation to overcompensate afterwards.
- Alternate-Day Fasting: Here you alternate between normal eating days and fasting days, where you either eat very little or nothing at all. It can drive significant weight loss and may improve several metabolic markers. However, it’s hard to sustain, it can clash with social life and it often leaves people low on energy or very hungry on fasting days. This method is fairly extreme and may not suit beginners or those with certain health conditions.
- The Warrior Diet: This involves eating only small amounts of raw fruit and vegetables through the day, then one large meal at night within roughly a four-hour window. Eating in the evening can suit some people’s natural hunger cues and it encourages whole, unprocessed foods. On the downside, that single meal can tip into overeating and it’s hard to fit all your nutrients into one sitting. As with alternate-day fasting, it can be tough or unsuitable for those with certain health conditions or dietary needs.
Does Intermittent Fasting Really Work and Is It Healthy?
Intermittent fasting has gained significant attention for its potential health benefits, and a considerable amount of research supports its effectiveness. However, it’s important to acknowledge that results can vary from person to person. It’s also worth noting that some of the benefits of IF are better studied and supported than others.
- Best-Proven Benefits: One of the most studied benefits of intermittent fasting is weight loss. This however seems to be mainly due to the reduction in calorie intake and an increase in fat burning during the fasting periods. Interestingly, IF may also help preserve muscle mass during weight loss, especially when combined with resistance training. There’s also strong evidence that intermittent fasting can improve various markers of metabolic health. This includes better regulation of blood sugar levels, improved insulin sensitivity, lower inflammation and positive changes in cholesterol levels. These in turn help reduce the risk of type 2 diabetes, heart disease and metabolic syndrome.
- Where More Evidence is Needed: Less well studied but even more exciting is the early evidence on the impact of intermittent fasting on cellular repair and healthy longevity. Fasting triggers processes like autophagy, where cells remove damaged components. This may protect against ageing and disease. There’s also increasing evidence to suggest that IF plays a role in improving brain health as well as reducing cancer risk and chronic inflammatory diseases like arthritis and Alzheimer’s. However, it’s crucial to note that more research is needed to support these findings, especially in humans.
- Not Right for Everyone: Despite these potential benefits, intermittent fasting is not a one-size-fits-all solution. Its effectiveness can depend on individual factors such as age, gender, health status and lifestyle. Moreover, intermittent fasting may not be healthy for everyone. This is particularly the case for certain groups like pregnant women, individuals with a history of eating disorders or those with specific medical conditions. If you have any health problems or take medications, you should consult a doctor before trying intermittent fasting. They will check whether it is safe for you and advise on the best type to follow.
How Do You Do Intermittent Fasting Properly?
Getting started with intermittent fasting can be a significant change to your routine and disrupt your normal activities. Here are some healthy tips to help make sure you begin intermittent fasting the right way:
- Choose the Right Method: Select an IF method that suits your lifestyle, work and health goals. For beginners, the 16/8 method is often best for its simplicity.
- Start Slowly: Ease into fasting gradually. If you’re doing the 16/8 method, begin by delaying breakfast for an hour and gradually increase the fasting period.
- Stay Hydrated: Drink plenty of water throughout the day, as staying hydrated helps reduce hunger pangs. You can also drink non-caloric beverages like black coffee and herbal tea.
- Plan Nutritious Meals: Focus on balanced, nutrient-dense foods during your eating window. Include a variety of proteins, whole grains, healthy fats, fruits and vegetables.
- Mind Your Portion Sizes: Avoid overeating during your feeding period, as this can counteract the benefits of fasting.
- Manage Hunger: If you feel hungry during fasting periods, distract yourself. Thinks that work include a walk, a hobby or a glass of water. Hunger pangs are often temporary and fade as your body adjusts.
- Monitor Your Body’s Response: Pay attention to how your body reacts. If you experience dizziness, extreme hunger or irritability, reconsider your fasting approach or see a healthcare professional.
- Be Consistent: Try to be as consistent as possible with your fasting schedule. However, life events and special occasions might require adjustments.
- Exercise Moderately: Light to moderate exercise can be healthy and complement your intermittent fasting regimen. Listen to your body and adjust the intensity of your workouts.
- Avoid Late-Night Eating: Try to finish your last meal a few hours before bedtime to aid digestion and improve sleep.
- Get Support: Connect with a community or support group for motivation and tips.
Intermittent fasting offers a sustainable path to improved health and wellness. It is backed by both historical practices and modern science. The benefits of intermittent fasting extend beyond weight loss. It’s also been linked to improved mental clarity, skin health and increased energy levels. It may also reduce risk factors for chronic diseases like type 2 diabetes and even prolong your lifespan. While these benefits are promising, it’s important to approach intermittent fasting thoughtfully. You will also do better if you build a sustainable fasting protocol around an overall healthy lifestyle. Remember, intermittent fasting is a personal experience, and what works for one person may not work for another. It’s important to listen to your body and adjust your approach as needed. Patience and flexibility are key to integrating IF into your lifestyle.
At City Skin Clinic, we are devotees of personalised skincare. Our online skin clinic offers safe and effective custom skincare treatments. Where appropriate our doctors use ingredients such as tretinoin and hydroquinone where appropriate to treat skin conditions like acne, hyperpigmentation, melasma and skin ageing. To start your personalised skincare plan, book a virtual video consultation or use our online consultation form. The journey towards great skin starts here.
This article is intended for general informational purposes only and is not a substitute for medical advice, diagnosis or treatment. Always consult a qualified medical provider for any medical concerns or questions you might have.
