We help you determine which type of fasting best suits your lifestyle based on your goals, lifestyle & the science.
Religious fasting has been a part of certain human cultures for hundreds of years. It is believed to have a cleansing effect on the body, and that it also helps a person on their spiritual journey by teaching them how to be patient and humble.
Fasting has become a viral trend in recent years among people who promote healthy lifestyles and longevity as we realized that fasting could be an excellent option for weight loss and better overall health.
“Most people are putting something caloric in their mouths essentially every minute they’re up, and we know that from an evolutionary perspective, this is not how humans or animals are geared to eat,” said Mark Mattson, a fasting and neuroscience researcher with the National Institutes of Health and an adjunct professor of neuroscience at the Johns Hopkins University School of Medicine.
Dr. Jason Fung, a nephrologist and one of the leading experts on intermittent fasting observed certain similarities between people who were struggling to lose weight and their eating habits. He highlighted that eating “healthy” was only one part of the weight-loss equation and that the potentially more important consideration is the actual timing of when we eat.
The main idea is that our ancestors weren’t able to eat all the time, and eating in a specific window and fasting for most of the time should come naturally for our bodies. Our circadian system regulates our hormones and eating habits, and by fasting, we help our hormones like insulin get back to normal, which should help us lose weight and lower the chances of conditions like diabetes.
But what does science have to say about all this? Can fasting benefit type 2 diabetes? Is it good for weight loss, and are there any other health benefits? Read on to learn all about it.
Types of Fasting
There’s a laundry list of fasting approaches popular today, and they all claim certain benefits. I thought I could break it down for you in a way that lets you determine which is best for you based on your lifestyle, goals and the science behind each. Let’s go.
Time-restricted eating (TRE) is a method of fasting where you consume food within a specified period during the day, usually 8-12 hours, and then fast for 12-16 hours. The overall goal of this type of fasting is to synchronize your feeding time with your circadian rhythm.
That is what researchers observed in a 2019 study concerning overweight adults published in the Journal Nutrients. Time-restricted eating affected the expression of several circadian clock genes. On top of that, TRE improved 24-hour glucose levels, altered lipid metabolism, and affected certain genes for longevity and autophagy like BDNF, SIRT1, and LC3A.
Another 2019 study observed the effects of early TRE on overweight adults. One of the results was increased fat oxidation, which led to fat loss. The subjects also exhibited lower ghrelin levels, which led to less desire to eat, increased feelings of fullness, and lowered appetite.
A 2018 pilot study in obese adults showed that TRE could be helpful with weight loss and reducing blood pressure.
Thanks to many reported benefits of TRE in adults, researchers of a 2019 pilot study wanted to see how TRE can affect older individuals. They picked sedentary people over 65 years old who had some mobility impairments. After following TRE for four weeks, outcomes included a decrease in body weight, increased walking speed, and improved the overall quality of life.
Dr. Rhonda Patrick, founder of Found My Fitness, is a strong supporter of TRE, and she believes it has incredible benefits on human longevity and life quality. She has done extensive research on nutrition, aging and lifestyle mediators and now educates public on healthspan, mental and physical performance. Her Youtube channel is a fantastic resource for learning about the in-depth science behind time-restricted eating.
Intermittent fasting (IF), also known as the 16/8 method is one of the most popular types of time-restricted eating. With this method, you eat 2-3 healthy meals and snacks of your choice during an 8-hour window and then fast for 16 hours. You can pick the times that you start and stop eating based on your schedule.
The benefits of intermittent fasting have been confirmed by research, and it is widely popular in the health community. The establishment and spread of IF in the bodybuilding world was thanks much in part to Martin Berkhan of Leangains sharing the approach back in 2006.
We have all been thought that we should have three meals a day with some snacks in between. But the truth is that this regime can lead to overconsumption, especially if your lifestyle is mostly sedentary. This overconsumption means a higher sugar intake, and that can lead to weight gain and conditions like insulin resistance and diabetes.
Luckily, intermittent fasting activates certain signaling pathways that promote stem cell-based regeneration, mitochondrial health, and reduces the risk of insulin resistance and cardiovascular disease. There is also a huge potential for weight loss.
We’ll get into more benefits of intermittent fasting further into this article.
5:2 is simple: you eat what you would typically consume for five days of the week, and then restrict your calories for two days. Fasting days shouldn’t be consecutive, and you would consume 25% of what you usually eat, which is typically 500-600 calories. It is essential to keep in mind that you should eat as healthily as you can during the days you are not fasting.
A randomized trial in young overweight women showed that a 5:2 diet is as useful as continuous energy restriction in terms of weight loss and reducing insulin insensitivity.
Some people don’t stick to a 5:2 regimen but like to fast every other day. This alternate day fasting (ADF) method showed increased fat oxidation and weight loss in nonobese individuals in a study published by the American Journal of Clinical Nutrition.
Animal studies showed that ADF could lead to a decreased risk of chronic diseases such as diabetes, cardiovascular disease, and cancer. However, more studies are needed to determine such effects in human populations.
Even though several studies show ADF’s ability to produce weight loss in those seeking to lose weight, lifestyle factors come into play, a 2017 randomized clinical trial showed no significant difference. We are n=1 so what may work for some may not work for others – so take that into account when evaluating your fasting options.
This form of fasting is similar to a 5:2 diet, and it involves participating in a 24-hour fast one to two times per week. Water, coffee, tea, and any other non-caloric beverage are allowed on your fasting days, but no solid food. Your eating days should be filled with nutrient-dense, and non -processed foods.
Given this type of fasting may induce insulin dips and spikes it’s important to slowly build-up to this type of fasting and discuss it with your physician before you begin. If you’re working with a practitioner they can help you maintain your level of performance by introducing ketones into your fast to help you acclimate.
By doing this type of fasting, you force your body to use its own stored glycogen as fuel, followed by fat as fuel, which brings you into a state of Ketosis. The adult body can store, on average, 1,500 calories of glycogen in the muscles, and 500 in the liver. Thus, depending on your diet and glycogen stores it can take between 1–4 days of fasting to achieve true ketosis.
The Warrior Diet
The Warrior Diet consists of fasting for most of the day and then eating 100% of your daily caloric intake in one sitting. The fasting period should last for around 20 hours with feasting to commence in a 4-hour window in the evening.
Dieters are encouraged to take a lot of liquids during the fast, and they can occasionally break the fast with small amounts of dairy products, raw fruits, and vegetables, or hard-boiled eggs. That is only for moments when daily performance seems to be affected significantly.
A 2017 randomized controlled trial demonstrated a slight increase in upper and lower body strength in young men who consumed all their calories within a 4-hour window, compared to subjects with no such restriction.
The Warrior Diet does not have any meaningful research to back it up. Its followers claim that it increases energy levels, burns fat, improves concentration, and helps with cell repair. However, people should be careful when attempting the Warrior Diet, as even though it seems like a stricter version of intermittent fasting, we still don’t know if there are any adverse health effects.
One controlled trial showed almost no difference between consuming one or three meals a day among healthy middle-aged adults. There was a slight change in body composition, including a decrease in fat and cortisol levels, but a slight increase in blood pressure and cholesterol, which are common cardiovascular disease risk factors.
Water fasting refers to prolonged periods when you are not allowed to consume anything besides water. This fast usually last from 24 to 72 hours. Only drinking water for longer than three days is not recommended without close medical attention.
It is still unclear whether water fasting is the best way for burning fat, as significant initial weight loss could be from water, carbs, and muscle loss. If you want to try fasting for weight loss, intermittent fasting may be a better idea.
ProLon or fast-mimicking diet is a 5-day meal program that provides your body with essential nutrients in the form of broths and bars that are not recognized by your body as food. Italian researcher Dr. Valter Longo establishes the ProLon diet, and its goal is to achieve the health benefits of fasting while getting the needed nutrients.
The fast-mimicking diet helps:
- In the prevention and treatment of autoimmune diseases. It could also be useful in reducing multiple sclerosis symptoms.
- Reprogramming of pancreatic cells to restore proper insulin secretion and reversion of diabetes. It also intervenes with diabetes progression in mice.
- Protect a healthy gut and reduces inflammatory bowel diseases.
- A 2017 study showed a reduction in body weight, total body fat, lower blood pressure, and decreased insulin-like growth factor in healthy subjects.
Benefits of Intermittent Fasting
With so many studies and institutions researching the effects of Intermittent fasting, it’s no wonder it’s mentioned as a benefit everywhere we turn. The benefits include:
- Enhances cognition
- Reduces inflammation
- Improves insulin resistance and prevents diabetes
- Increases longevity
- Improves outcomes of diseases
- Supports weight loss
Is Fasting Good for My Brain?
Fasting has been shown to increase rates of growth and development of new brain cells and nerve tissues (neurogenesis), allowing you to: think more clearly, remember things more efficiently, and effortlessly focus on what you are doing. You can thank something called brain-derived nerve-growth factor (BDNF) which is upregulated while fasting, for that.
Studies in mice showed significant improvement in brain structuring and functioning. IF supports cell autophagy that extends in the brain and can help reduce symptoms of mental decline associated with conditions like Alzheimer’s and Parkinson’s disease.
Intermittent Fasting to Reduce Inflammation
Acute inflammation is a normal and essential immune response that helps your body fight off infections. However, chronic inflammation can cause serious long-term health issues.
Fasting has been shown to significantly decrease inflammatory markers and promote better health. Studies in mice show IF can also help the neuroimmune system fight off inflammation, which leads to enhanced learning and memory.
How Does Intermittent Fasting Help Insulin Resistance and Diabetes?
It’s no secret that Type 2 Diabetes is an epidemic issue throughout the country. Many people find it unmanageable to stick to a specific diet seven days a week and find fasting to be a sustainable alternative option. Luckily, there has been a lot of evidence on how fasting may prevent obesity-related insulin resistance.
Human studies have shown that through intermittent fasting, blood sugar can decrease by 3-6% and insulin by 20-31%.
By reducing insulin resistance through fasting, you are increasing your body’s sensitivity to insulin, which allows your body to transport glucose from your bloodstream into your cells more efficiently. That will help prevent spikes and crashes in your blood sugar levels.
Fasting for diabetes is an excellent option as it can help patients with type 2 diabetes reduce body weight and glucose levels.
Fasting and Longevity
Although all the studies so far are performed on mice, IF has the potential to be a key to a long healthy life. IF alters the expression of some genes, which changes a process called autophagy. Autophagy is a natural way of eliminating cells that are damaged, ill, or unable to perform their functions. That way, our bodies keep working correctly, and it also helps eradicate certain diseases like cancer.
Dr. Peter Attia is one of the many experts who fully support fasting for longevity and improved healthspan.
Improving Oncome of Diseases
We have seen that IF can help with diabetes, Alzheimer’s, and Parkinson’s disease, but it can be beneficial to other conditions as well.
IF can help reduce the effects of oxidative stress, which is connected to aging and many chronic diseases. It is also useful for cardiovascular health and can even prevent cancer growth through increased autophagy.
Is Intermittent Fasting Effective in Weight Loss?
Most people are introduced to intermittent fasting for weight loss benefits. It’s fantastic for that for reasons well beyond the calorie-in calorie-out old school model of fat loss. Furthermore, by combining intermittent fasting with fasted cardio or weight lifting working, goal dependent, you can get amazing results.
Studies strongly demonstrate that IF can help with weight loss, increased muscle mitochondrial biogenesis via the upregulation of HGH and resting energy expenditure. The International Association for the Study of Obesity demonstrated that intermittent fasting is at least as effective in weight loss as caloric restriction and that it is a better option for losing belly fat due to its effects on hormones.
The good thing is that this weight loss is attributed to fat burning, lower cholesterol, and decreased adiposity. With increased energy levels and fat burning, your aesthetic results can be fast-tracked.
Why Should I Choose Intermittent Fasting over Other Diets?
The research on intermittent fasting and extended fasts are compounding extremely fast given the benefits across so many conditions, disease states and longevity. You can easily implement it into your everyday routine and best of all – it’s practically free. You don’t even have to give up your favorite morning coffee, as intermittent fasting and coffee are compatible, and you won’t break a fast by drinking it.
Incorporating fasting into your life, whether regimented or intuitively can be a great way to dip your toe into the world of self-experimentation. It’s easy, free, flexible and continues to show its efficacy.
If you’re interested in exploring fasting, self-experimentation and quantified progress let’s talk. We have a program that incorporates Heads Up Health data tracking, continuous glucose monitoring so you can see how you respond to various foods, peptides to maximize your fat loss and more at the practice.
The Information in this guide is designed to complement, not replace, the relationship between a patient and his/her own physician and is for informational purposes only. The Information is not intended to be medical advice, diagnosis, or treatment. Always seek the advice of your physician or another qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you saw or read on my website.