Let's face it – most of us are suckers for good food and plenty of it. Eating and sharing meals is a central part of many cultures; it’s also the way we get our energy and, often, the way we segment our days. 

But our bodies need a break from the constant onslaught of calories from time to time. There is a surplus of food selection and this generally results in a surplus of calories consumed for most people.

That's where fasting comes in: an age-old practice that’s making a serious comeback in modern times as a popular biohack. It’s more than just skipping a meal or two. Fasting can offer numerous health benefits if done correctly. 

Eating and caloric restriction are incredibly broad, complex topics, and it’s always best to hear from a variety of educated professionals to gain a well-rounded understanding. I personally do the typical 16-hour fasting windows; I eat during an eight-hour window, then only consume water for the remaining 16 hours, and it works super well for me.

But what do the experts say, and how can we learn from the best? Andrew Huberman’s recent podcast with Dr. Satchin Panda is a great place to start; Dr. Peter Attia has some excellent resources on his official website and podcast, too.

Now, let's jump into exploring the world of fasting and restricted eating. We'll cover different types of calorie restriction diets, examine their potential benefits, and help you determine which method might be best for your unique needs. So grab a drink (full sugar, low sugar, no sugar – however you wish!), and let's dive in.

What Is Fasting?

Fasting is the act of abstaining from food for a specific period, and on purpose – not because your fridge is empty. 

A fast can last anywhere from a period of hours to multiple days, depending on the type of fast chosen. One study of 1422 test subjects showed that periodic fasts of up to 21 days could be safe (if executed correctly, with an intake of 200–250 kcal per day). 

Controlled fasting usually looks like a period of around 12 hours where the participant restricts caloric intake either partially or entirely in order to achieve certain health benefits. They will do so intermittently; in other words, they will take part in these fasts at regular intervals with breaks in between. 

It's crucial not to confuse starving yourself with fasting. In essence, fasting is like giving your body a well-deserved vacation from digesting all the food we throw at it daily. While some people still consume things like bone broth, coffee and some electrolytes during a fast, although it is technically not a fast, the principles of caloric restriction are still providing a benefit.

Starvation wreaks havoc on your body, but controlled fasting comes with numerous health perks. So, what are they?

What Are the Benefits of Fasting or Calorie Restriction?

Fasting might seem counter-intuitive at first, especially since we're taught very basic biological rules growing up: eating too much is ‘unhealthy,’ eating regularly is ‘normal,’ and not eating leads to starvation or malnourishment. When I first heard about fasting, it certainly confused me – but I decided to look into it further. In reality, our bodies aren't so simple and can benefit from periods of fasting.

Weight Loss

One of the primary reasons people turn to fasting is for weight loss or weight management. By limiting your eating window, you tend to consume fewer calories, leading to a calorie deficit and subsequent weight loss without relying on extreme diets. Moreover, fasting can help boost metabolism by promoting fat-burning and preserving lean muscle mass.

Improved Insulin Sensitivity

Fasting has been shown to improve insulin sensitivity and lower blood sugar levels by reducing insulin resistance. This improvement means that your cells respond better to insulin signals, allowing them to use glucose more effectively – ultimately lowering your risk of developing type 2 diabetes.

Enhanced Mental Clarity And Focus

When we fast, our bodies switch from using glucose as their primary fuel source to utilising ketones produced from stored body fat through a process called ketosis. Ketones are known for providing energy more efficiently than glucose does, resulting in enhanced cognitive function and sharper focus during periods of fasting.

Autophagy Promotion

Autophagy is a natural cellular process where damaged cell components are broken down and recycled for energy production or building new cells – think spring cleaning, but inside your body! Prolonged fasting allows autophagy processes to occur more efficiently throughout our system; this helps keep us healthy by getting rid of waste products within our cells while also encouraging cell regeneration.

(Note that research in this area is more limited than in other areas mentioned. It’s always best to consult your physician for advice). 

Reduced Inflammation

Chronic inflammation is linked with numerous diseases, such as heart disease, cancer, and arthritis, among others. One benefit associated with intermittent fasting (IF) includes reduced levels of inflammation. By giving your body a break from digestion, it can focus on healing and repair processes that help reduce overall inflammation.

Improved Cardiovascular Health

Studies have shown that fasting can help improve heart health by reducing blood pressure, cholesterol levels, and triglycerides – all crucial factors in maintaining good cardiovascular health. With heart disease being one of the leading causes of death worldwide, fasting may play a role in reducing this risk.

Longevity And Anti-Aging Effects

Though more research is needed, calorie-restriction diets could increase life expectancy and promote healthier aging due to their impact on cellular processes such as autophagy, reduced inflammation, improved insulin sensitivity, and enhanced mitochondrial function.

Top 5 Ways of Fasting

Now that we've explored the benefits, let's dive into five popular fasting methods. Keep in mind that everyone is different; what works for one person may not work for another, so it's essential to find the method that best suits your lifestyle and goals.

16:8 Intermittent Fasting (If)

This method involves eating during an 8-hour window while fasting for the remaining 16 hours each day. The most common approach is skipping breakfast and consuming meals between noon and 8 PM. IF has gained popularity due to its flexibility, making it easier to adopt as a long-term lifestyle choice rather than a temporary diet.

5:2 Diet

Following this plan requires you to eat regularly for five days of the week while restricting calories on two non-consecutive days – usually limiting intake to about 500-600 calories per "fasting" day. 

The idea behind this approach is that by periodically reducing calorie intake, you can still enjoy regular meals most of the time while reaping some fasting benefits.

Alternate Day Fasting (ADF) 

True ADF entails switching between full-day fasts where no solid food is consumed and regular eating days without any restrictions on caloric intake or food choices. For those who find complete fasts challenging, modified ADF allows consumption of around one-quarter of daily calorie needs (~500 calories) during fasting days instead.

24 Hour Fast 

As the name suggests, this type involves abstaining from food for a full day (24 hours). Some people choose to do this once or twice per week as part of their routine; others might opt only when they feel like they need a reset after overindulging in food or drink during social events or vacations.

Warrior Diet

This diet consists primarily of undereating during daylight hours, followed by consuming one large meal at night within a 4-hour window. The daytime phase permits small amounts of raw fruits, vegetables, and protein but restricts significant caloric intake until the nighttime feast.

More extreme fasts involve consuming water only for a period of several days. For instance, Dr. Peter Attia shared in an interview with Thomas DeLauer that he used to regularly fast for three consecutive days each month and 7-10 days per quarter. 

However, it’s important to understand that under extreme fasting like this, you are likely to lose a lot of muscle mass. Dr. Attia experienced this himself and has since altered his fasting habits. 

“The reality is that you’re going to lose a lot of muscle mass...Today, I just don’t feel that that trade-off is worthwhile,” he said. “My rule of thumb for any eating pattern is that you must eat enough to maintain lean mass (muscle) and long-term activity patterns,” he says.

Which Type of Fasting Method is Best For Me?

Choosing the right fasting method depends on your individual preferences, lifestyle, and goals. Here are some questions to consider when deciding which option might suit you best:

1. How flexible is your schedule? If you have a predictable daily routine or a consistent work schedule, methods like 16:8 IF or Warrior Diet might be easier to implement as they require specific eating windows that can be easily planned in advance.

2. What's your appetite like in the morning? If you're not typically hungry upon waking up or always feel rushed during breakfast time, skipping breakfast with 16:8 IF could be a natural fit that aligns well with your body's needs and everyday patterns. 

3. Can you handle full-day fasts? For those who find it difficult to go without food for an entire day due to intense hunger pangs or low energy levels, options like ADF or the 24 Hour Fast may not be ideal – instead, consider trying the more moderate 5:2 Diet that allows for limited caloric intake on fasting days while still providing some nourishment.

4. Are social commitments important to you? If dining out with friends or attending events often revolves around food and drink consumption during evening hours (or weekends), maintaining a Warrior Diet could prove challenging because it requires nighttime feasts within strict windows.

In this case, other options such as 16:8 IF may provide more flexibility when navigating social situations involving meals outside of home environments.

5. Do you have any pre-existing health conditions? Certain medical issues such as diabetes, kidney disease, heart problems, or metabolic disorders may require closer attention when considering various fasting methods; consulting with healthcare professionals can help determine which approach would

6. What are your fitness goals? Depending on whether weight loss/maintenance/gain is desired alongside muscle mass-building efforts (e.g., strength training), different fasting protocols can be tailored accordingly to meet these objectives more effectively.

Keep in mind that these are just guidelines to help begin the process. Dr. David Sinclair, a well-respected ageing and epigenetics expert, says it best:

“You are an individual. You’ve got a different lifestyle and a different tolerance for pain and hunger...you’ve got a different microbiome. When we recommend things, what we’re really saying is, does that work for you?”

It is perfectly okay to listen to expert recommendations, but at the end of the day, you may not find your ideal fasting plan in one attempt – and that’s preferable. It’s best to try out different regimens and see what feels right for your body.Listen to your body and consult with a healthcare professional if needed before embarking on any fasting journey. By understanding and addressing individual circumstances, the most appropriate fasting method can be selected for long-term success while minimising potential adverse effects on one's overall health status.

Things To Remember When Fasting

During fasting periods, it's crucial to maintain proper hydration levels by drinking water regularly. Supplementing with electrolytes like sodium, potassium, and magnesium can help prevent imbalances that may cause cramps or other discomforts.

Be mindful of your energy level during fasting days – don't expect to be at peak performance if you're just starting out. As your body adapts to this new way of eating over time, you'll likely notice an increase in stamina despite caloric restrictions.

Ensure your body has enough nutrients (protein, vitamins, minerals) on non-fasting days to promote muscle repair and recovery after workouts or strenuous activities.

Set realistic expectations about what you hope to achieve through fasting – whether it's weight loss, improved mental clarity or general health improvements – so that you have a clear purpose driving your efforts.

And of course, always consult a medical professional before commencing a specialized diet or eating schedule. It’s better to have reassurance from a well-versed practitioner than to chance it alone. 

Frequently Asked Questions

Here are some frequently asked questions about fasting and restricted eating:

Is Fasting Safe?

Generally, fasting is considered safe for most healthy adults when done appropriately. However, it may not be suitable for pregnant or breastfeeding women, children, and adolescents, individuals with specific medical conditions, or those recovering from an illness. Always consult your healthcare professional before starting any new dietary regimen.

Should I Do Fasted Exercise?

Exercising in a fasted state can help burn stored body fat more efficiently; however, the intensity of the workout should be taken into account. Light-to-medium intensity workouts can typically be performed without issue while fasting – but if you're aiming for high-intensity sessions or heavy weightlifting, having a pre-workout meal might better suit your energy needs. 

Does Fasting Help With Weight Loss?

Yes! Fasting can aid in weight loss by creating a calorie deficit while preserving muscle mass – resulting in improved metabolic rate even after resuming regular eating patterns.

What Should I Eat To Break The Fast?

When breaking your fast, opt for nutrient-dense foods that aren't too heavy on your stomach (e.g., vegetables, lean protein sources like chicken breast or fish). The goal is to replenish essential nutrients without causing digestive distress following a prolonged period of caloric restriction. Breaking the fast with meals high in fat, sugar or fibre can cause stomach upset and bloating.

To break the fast, I usually opt for a small amount of bone broth, some gluten free bread with a couple of eggs, a small amount of fermented kimchi or sauerkraut and a crisp leafy salad mix - this seems to cause minimal upset and isn’t an overly large portion, that said, everyone is different so experiment with what works for you.

Conclusion

Fasting and restricted eating offer numerous health benefits ranging from weight loss to improved mental clarity and reduced inflammation – making them attractive options to consider incorporating into one's lifestyle alongside balanced nutrition and regular physical activity.

The key lies in choosing the right method based on individual preferences and goals while paying attention to proper hydration as well as repair/recovery needs during non-fasting periods.

As always, consult with a healthcare professional before embarking on any dietary changes – especially when considering implementing fasting protocols into your routine.