Intermittent Fasting: Does It Really Work?

Tired of hearing your mate tell you that ‘intermittent fasting has changed my life’? Well, we’re here to give you the unbiased truth about intermittent fasting. Does it really work? Let’s see.

Intermittent fasting has risen in popularity as a way to improve your overall health and shed some extra pounds around Christmas. However, with so much information available online, it can be difficult to know where to start or who to trust. That's why we've done all the research for you, with no bias. We've looked into the benefits of intermittent fasting thoroughly to help you have a concise understanding of the topic. Consider us your go-to source on intermittent fasting results so you can rest assured that you're receiving the most accurate and helpful content on intermittent fasting.

Fasting, in its simplest terms, is the practice of abstaining from food for a certain period of time. While most diets focus on what you eat, intermittent fasting focuses on when you eat. The practice of fasting has a long history, with evidence of fasting being practised in various cultures and religions across the world (Johns Hopkins Medicine).
 

While the reasons for fasting can vary, some people do it for benefits such as weight loss, increased energy, and improved mental clarity. While fasting may initially seem intimidating, many individuals find it to be an effective method for achieving their health and wellness goals. By providing the body with periods of rest and a break from the constant influx of calories, you may see improved overall health and well-being (Johns Hopkins Medicine).
 

While intermittent fasting sounds like a new, modern trend, it is a practice that actually dates back to prehistoric times. Though, that wasn’t necessarily by choice. Before we learned to farm, we were hunters and gatherers who ate to survive, and as a result, we learned to endure long periods without eating. After all, hunting and gathering is nowhere near as easy as roaming through isles at Coles or heading through the Maccas drive-thru.
 

So, why has intermittent fasting become so popular? Because we no longer have the same discipline with ourselves. So much of our spare time is dedicated to computers, phones, television, and streaming, and so much of our time is spent in sedentary positions. We also snack a lot more, sleep less, and go outside less. Intermittent fasting has become a viable solution because it can help you manage your weight by restricting your window of eating. This, in turn, can help you manage your caloric intake more effectively.
 

Here are some of the most common methods for intermittent fasting.

This is the easiest way to go if you’re just getting started because it has relatively small requirements. Basically, if you break your fast at 8 am, stop eating at 8 pm. This is a sizeable window, with research suggesting that fasting for 10-16 hours can support weight loss by turning fat stores into energy (Leonard, J. 2023).

The 16:8 method is probably the most common form of fasting and leaves an eating window of 8 hours. Also known as the ‘lean gains diet’, this method is helpful if you’re looking for intermittent fasting results relating to weight loss. The easiest way to pursue this method is to skip breakfast each morning, making it easier to consume everything in that 8-hour window (Leonard, J. 2023).

When we save 5:2, we’re talking about days here, not hours. Fasting for 2 days a week can help you restrict your calorie intake, with a study suggesting that this style of fasting reduced insulin levels and improved insulin sensitivity. People generally split their fasting days into separate days of the week, so there is a non-fasting day separating them (Leonard, J. 2023).
 

While these are the most common methods of fasting, you can adjust the way you fast to suit your needs and goals. Some people choose to fast one day per week, while others may try alternate-day fasting. It’s about what works best for you and finding an achievable compromise.

The benefits of fasting, also known as time-restricted eating, have been researched extensively through various studies. With benefits that support the health of your body and brain, we’re going to run through some of the most effective evidence-backed benefits that intermittent fasting can illicit.

Fasted cardio has become a popular way for people to lose weight and burn fat. By performing cardio exercise in a fasted state, meaning when you haven't eaten for several hours, your body is forced to use stored fat as its primary source of energy. Additionally, reducing your eating window or prolonging the period of time when you don't eat can also help kickstart your body into burning fat. By reducing your caloric intake, you create a calorie deficit, which can lead to weight loss. Although it may not be suitable for everyone, incorporating fasted cardio and reducing your eating window can be a helpful way to shed those extra pounds (Gunnars, K. 2023).
 

Let’s take a look at how time-restricted eating can specifically support your weight goals.

Fasted cardio is a popular technique for those looking to lose weight. By engaging in aerobic exercise on an empty stomach, the body is forced to tap into its fat stores because there is no glucose. This can lead to a faster rate of weight loss compared to other forms of cardio, as the body is primed to burn fat as fuel. Additionally, fasted cardio has been found to increase insulin sensitivity and improve metabolic rate, further supporting weight loss results. Although it may be challenging to exercise without eating first, the benefits of fasted cardio are well worth it for those seeking to shed excess weight and improve their overall health (Migala, J. 2023).

When you fast for 16 hours, your body begins to tap into stored fat for energy, which ultimately leads to weight loss. Not only does it help you shed those extra pounds, but it also has other health benefits, such as reducing inflammation and improving insulin sensitivity.  It is important to remember that it is the quality of calorie intake that matters vs the calorie expenditure. If you fill your eating window with low-quality food that is high in calories during your eating window, then you are going to undo all of your hard work. It is important to balance your intermittent fasting with a balanced and nutritious diet (Streit, L et al. 2023).

So, when does the body start burning fat during fasting?
 

This usually occurs during the second stage of ketosis, which is between 12-18 hours of fasting. Fasting for 16-18 hours a day allows you to burn through your body fat, which makes it easy to stay in a deficit and lose weight (Kinnu).

Intermittent fasting has been shown in studies to assist with insulin resistance, a condition that can lead to type 2 diabetes and can be an effective way to improve insulin sensitivity and regulate blood sugar levels. One study published in the journal International Journal of Endocrinology suggested that intermittent fasting can yield results on glucose and lipid metabolism and insulin resistance in patients with impaired glucose and lipid metabolism. Intermittent fasting was suggested as an alternative to calorie-restricted diets as a method of weight management, with a study on the effects of intermittent fasting on health, aging, and disease suggesting that intermitted fasting diets can help to produce gradual weight loss, lower blood pressure, and have anticarcinogenic effects (Yuan, X et al. 2022).
 

While more research is needed, these findings are promising and suggest that intermittent fasting may be a valuable tool for those looking to improve their insulin sensitivity and overall health.

As you probably know from your busy lifestyle, your body doesn’t stop working, and even the most mundane acts like breathing, drinking, and eating are putting your body to work. Time-restricted eating has been used to help your body reset. By restricting your window of eating, you allow your digestive system to rest, which can relieve and reduce oxidative stress and inflammation. A 2018 review on the impact of intermittent fasting on human health suggested that intermittent fasting can support your body’s response to oxidative stress and can be an effective approach because of its ability to cope with conditions like diabetes, blood pressure, and cardiovascular disease. Another 2019 review on how dietary intake regulates the circulating inflammatory monocyte pool suggested that intermittent fasting can also help to combat inflammation by reducing monocyte metabolic and inflammatory activity (Gunnars, K. 2023). 

Intermittent fasting has been shown to be a potentially beneficial method for supporting cellular repair and promoting autophagy. Autophagy is the process by which cells clean out old or damaged cellular components, and this process is essential for maintaining cellular health. Intermittent fasting encourages autophagy because it triggers a metabolic switch that causes the body to turn to its fat stores for fuel instead of relying on glucose. This switch triggers metabolic and cellular changes that lead to improved cellular function and repair, particularly in the brain and heart (Davis, C. 2023).

By restricting the window in which food is consumed, the body can prioritise cellular repair and rejuvenation, leading to a host of benefits for overall health and well-being. Depending on your metabolism, significant autophagy can take 2-4 days of fasting and is believed to begin when glucose and insulin levels drop significantly. Research has suggested that autophagy starts to peak at around 48 hours of fasting. However, these studies have been taken on animals, so it is important to consult a medical professional before attempting to fast for autophagy. The ketogenic diet is popular among those practising intermittent fasting, as it is believed to induce ketosis and autophagy. However, there are no major studies on humans that provide certain evidence (Davis, C. 2023).

When it comes to diet and exercise trends, there always seems to be a new "miracle" solution that promises to deliver fast and effective results. However, with every trend comes risks, and intermittent fasting is no different. Potential negative side effects of intermittent fasting can vary from person to person, depending on their current medical diagnosis, age, sex, and other factors.
 

It's important to do your research and consult with a medical professional before starting any new diet or exercise regimen. While intermittent fasting has shown promise for weight loss and improved overall health, it may not be suitable for everyone. As with any lifestyle change, it's essential to listen to your body and adjust accordingly.

If you're an athlete, you may want to think twice before trying intermittent fasting. Exercising in a fasted state can be detrimental to your athletic endurance - unless, that is, you're using fasting to lose weight or for other short-duration exercises. This is because athletes with high-energy needs, such as marathoners or bikers, require quick boosts of glucose for endurance training, which the slow-burning fuel of fat may not provide. When you wake up, your glycogen stores are limited, so your body turns to fat to burn. This can lead to lethargy and a decrease in athletic endurance, making it a less-than-ideal choice for serious athletes. Long-term fasting can result in a loss of muscle mass while also impacting heart rate, fatigue, oxygen uptake and cardiopulmonary function. Exercise psychologists found that prolonged fasting can impact endurance exercise performance. Because fatty acids are the main source of energy in the skeletal muscle, fasting may be damaging to your athletic endurance (Liu, M et al. 2022).

Time-restricted eating can lead to loss of muscle mass if not done correctly. It is important to keep in mind that time-restricted eating causes loss of both fat and lean muscle mass, so it may not be the best diet for those looking to build muscle. Long-term fasting can cause muscle catabolism or burning out, resulting in protein being used as an energy source if stores are completely empty and adequate calorie and nutrient intake is not achieved. However, replenishing stores with protein is necessary to sustain muscle mass and minimise loss. Lack of protein is a key factor in muscle loss during time-restricted eating, but it is also important not to go overboard. Protein should only take around 15-25% of your daily calorie intake (Galzerano, S. 2023).

Intermittent fasting may cause hormonal disruption, particularly in women's monthly cycle. There are four phases in a typical woman’s menstrual cycle including the menstrual phase, follicular phase, ovulation phase and luteal phase. And if you thought that was, then you’d be wrong because there are also three major hormonal stages in a woman’s life (premenopausal, perimenopausal, and postmenopausal) that come with their own hormonal changes too. These changes can be impacted by time-restricted eating.

If you are practising time-restricted eating, it is best to do so in the first 1-15 days of your cycle, and your hormone profile should be better suited to handle the stressors associated with fasting. Caloric restriction later in your cycle (21-28 days, to be exact) can impact progesterone levels, which are critical for maintaining good health. This can lead to potential effects on cortisol, insulin, estrogen and progesterone, causing disruptions that can negatively impact the body. Therefore, it is important to approach fasting with caution and seek professional guidance to ensure hormonal balance is maintained (DeCesaris, L. 2023).

Intermittent fasting has gained a lot of attention for its weight loss benefits. However, it can also affect your results and cause overeating if not done correctly. The main issue is that a restricted eating window can lead to binge eating. For example, if you only have a six-hour period to eat, you may find yourself consuming more than necessary as soon as the clock strikes done. This can easily result in consuming more calories than needed, leading to weight gain instead of weight loss. It is essential to maintain control during the eating window and plan meals accordingly to avoid overeating. The reason time-restricted eating can lead to overeating is that your appetite hormones can go into overdrive when you go long periods without eating (Harvard Health Publishing. 2023).

Overall, intermittent fasting is a valuable tool for weight loss and overall health. Not only does it simplify eating patterns and encourage mindfulness around food choices, but it can also improve metabolic health, reduce inflammation, and potentially reduce the risk of chronic diseases. However, it is important to approach intermittent fasting with caution and listen to your body's signals. It may not be suitable for everyone, and those with certain medical conditions should consult with a healthcare provider before giving it a try. With proper implementation and guidance, intermittent fasting can be a safe and effective strategy for achieving health and wellness goals.

If you want to learn more about time-restricted eating and how it can suit your lifestyle, or you need help finding the right supplements to support your intermittent fasting results, don’t hesitate to reach out to our team at ASN. Simply head in-store or reach out online, and our friendly team will gladly help you find the information you’re looking for.

Johns Hopkins Medicine, ‘Intermittent Fasting: What is it, and how does it work?’ Johns Hopkins Medicine, accessed December 2023, https://www.hopkinsmedicine.org/health/wellness-and-prevention/intermittent-fasting-what-is-it-and-how-does-it-work

Leonard, J. 2023, ‘Six ways to do intermittent fasting’, Medical News Today, accessed December 2023, https://www.medicalnewstoday.com/articles/322293

Yuan, X et al. 2022, ‘Effect of Intermittent Fasting Diet on Glucose and Lipid Metabolism and Insulin Resistance in Patients with Impaired Glucose and Lipid Metabolism: A Systematic Review and Meta-Analysis’, PubMed Central, accessed December 2023, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8970877/

Gunnars, K. 2023, ‘What Is Intermittent Fasting and How Does It Work?’ Healthline, accessed December 2023, https://www.healthline.com/nutrition/10-health-benefits-of-intermittent-fasting#TOC_TITLE_HDR_3

Liu, M et al. 2022, ‘Effects of Low/Medium-Intensity Exercise on Fat Metabolism after a 6-h Fast’, Environmental Research and Public Health, accessed December 2023, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9736603/

Galzerano, S. 2023, ‘Intermittent Fasting Can Lead to Muscle Loss, But It Doesn’t Have to - Here’s Why’, Jefferson Health, accessed December 2023, https://www.jeffersonhealth.org/your-health/living-well/intermittent-fasting-can-lead-muscle-loss-it-doesnt-have-heres-why

DeCesaris, L. 2023, ‘How Intermittent Fasting Affects Women’s Hormones’, Rupa Health, accessed December 2023, https://www.rupahealth.com/post/how-intermittent-fasting-affects-womens-hormones#:~:text=Calorie%20restriction%20can%20negatively%20affect,keep%20your%20progesterone%20levels%20healthy

Harvard Health Publishing. 2023, ‘4 intermittent fasting side effects to watch out for’, Harvard Medical School, accessed December 2023, https://www.health.harvard.edu/staying-healthy/4-intermittent-fasting-side-effects-to-watch-out-for#:~:text=It%20may%20cause%20you%20to,you%20are%20deprived%20of%20food.

Gunnars, K. 2023, ‘How Intermittent Fasting Can Help You Lose Weight’, Healthline, accessed December 2023, https://www.healthline.com/nutrition/intermittent-fasting-and-weight-loss

Migala, J. 2023, ‘Should You Fast Before Your Next Cardio Workout?’ Peloton The Output, accessed December 2023, https://www.onepeloton.com/blog/fasted-cardio/

Kinnu. ‘The Different Stages of Fasting: What to Expect’, Kinnu, accessed December 2023, https://kinnu.xyz/kinnuverse/lifestyle/intermittent-fasting/stages-of-fasting/#:~:text=Stage%202%20(12%2D18%20Hours)%3A%20Partial%20to%20Full%20Ketosis,-Depending%20on%20your&text=In%20Stage%202%20of%20fasting,calorie%20deficit%20and%20lose%20weight.

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