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Unlocking the Power of Fasting—Your Practical Guide to Longevity and Health.

August 9, 2024

There are so many types of fasting diets out there—water fasting, juice fasting, dry fasting, and more—it’s easy to get lost in the noise.

So how do you know if fasting is right for you and which type? And what if you’ve tried fasting before but found it too challenging to stick with?

As someone who’s passionate about promoting health and longevity, I can tell you that the benefits of fasting are undeniable—it activates survival pathways in the body, enhancing anti-aging genes, immune function, reducing inflammation, and improving DNA repair.

It also promotes metabolic flexibility—allowing your body to efficiently use stored fat as energy—and can enhance mental clarity and energy levels.

And the thing is—fasting doesn’t have to be extreme to be effective. You don’t have to feel deprived or overwhelmed.

The key is to realize that fasting isn’t a “one size fits all” solution, and it’s essential to find a method that suits your lifestyle and health needs.

By starting with a manageable fasting schedule and paying attention to what you eat, you can make intermittent fasting a sustainable and beneficial part of your lifestyle. Let me walk you through how you can incorporate fasting into your routine, even if you’ve found it challenging before.

Fasting and Its Benefits

Fasting, at its core, is simply a period of voluntary abstinence from food. For example, the 12/12 method involves fasting for 12 hours followed by eating within a 12-hour window. This could be as simple as having dinner at 6 p.m. and then not eating until 6 a.m. the next morning.

Another option is the 16/8 method, which involves fasting for 16 hours—like eating dinner at 6 p.m and then not eating again until breakfast at 10 a.m. the following morning—and then eating within an 8-hour window.

Fasting doesn’t have to be about extreme deprivation or drastic dieting but rather a structured approach to eating that can offer numerous health benefits that go beyond weight loss or body composition changes (although it can be effective for weight management¹).

Scientific research shows that fasting helps:

Improve heart health: Fasting can help lower cholesterol levels and blood pressure, reducing the risk of cardiovascular diseases.²
Enhance insulin sensitivity and metabolism: Fasting improves your body’s response to insulin, which helps regulate blood sugar levels and reduces the risk of type 2 diabetes. It also boosts metabolic processes, aiding in weight management and energy utilization.³
Promote brain health and cognitive function: Increased levels of brain-derived neurotrophic factor (BDNF) during fasting support neuron growth and maintenance, enhancing memory, learning, and overall cognitive function. This can help protect against neurodegenerative diseases like Alzheimer’s in the long run.⁴
Boost immune function: Fasting can enhance immune function by reducing inflammation and promoting the regeneration of immune cells. This process helps the body better respond to infections and may increase resistance to various diseases, supporting overall immune health.⁵
Activate "longevity switches": Fasting triggers genetic pathways that promote cellular repair and longevity, often referred to as "longevity switches." A crucial part of this process is called autophagy, which literally means "self-eating."⁶

Autophagy—The Body’s Housekeeping System

Autophagy is your body’s natural mechanism for cleaning out damaged cells and regenerating new, healthier ones. It’s like a cellular housekeeping process, where your body breaks down and recycles old cell components.

This self-cleaning mechanism is crucial for cellular health and function. This not only helps in removing potential sources of diseases, but also provides energy and building blocks for cellular repair and regeneration.

Fasting is one of the most effective ways to stimulate autophagy. When you fast, your body experiences a reduction in nutrient intake, signaling a shift from growth mode to maintenance and repair. During this time, insulin levels typically drop, and the body may start to use stored fats for energy. This metabolic shift helps contribute to the activation of autophagy.

Autophagy and Types of Fasting

Understanding the timeframe for when autophagy kicks in during fasting can help you optimize your fasting practice to gain the maximum health benefits.

Typically it begins to ramp up after several hours of fasting, with significant activation occurring after 12-24 hours without food. However, the exact timing can vary based on factors such as your metabolic rate, activity level, and overall health.

► Time-restricted eating involves eating all meals within a specific window of time each day and fasting for the remaining hours (like the 12/12 or the 16/8 method). It may or may not include calorie restriction.

Time-restricted eating begins to stimulate autophagy, although this process may not reach its peak intensity. This fasting option could work well for those new to fasting or looking to ease into longer fasting periods. But it’s enough to get the health benefits when practiced consistently.

► Longer fasts (24 Hours): Fasting for 24 hours or longer can significantly increase autophagy, as the body has exhausted its immediate energy reserves and shifts more towards breaking down stored fats and clearing out cellular debris. This period is effective for deeper cellular cleaning and metabolic benefits.

Alternate-day fasting: This method alternates between days of normal eating and days where caloric intake is significantly reduced, typically to 0-25% of usual intake.

Periodic prolonged fasting: Engaging in multi-day fasts periodically to trigger deeper metabolic changes, including increased autophagy and ketone production. (Although it can induce muscle loss, which is an undesirable side effect of this option.)

While these longer fasting methods can offer significant metabolic and cellular benefits, I personally avoid them due to my unique physiological response—I’m what's known as a “lean mass hyper-responder” (a topic for another newsletter)—which makes me more likely to lose lean muscle mass during longer fasting periods.

This is why it’s important to pay attention to how different fasting methods affect you as an individual, versus just adopting one-size-fits-all advice.

Before You Start—is Fasting Right for You?

Take a moment to reflect on your individual health status and goals to see if fasting is right for you.

► Consider your personal health goals. Is it weight loss, improving metabolic health, enhancing mental clarity, or something else? Having clear objectives will help you choose the right fasting method and stay motivated.

► Fasting needs may vary by age, sex, and health conditions. For example, younger women might start with shorter fasts. Longer periods of fasting can be problematic for some women because they may disrupt hormonal balance, leading to issues like irregular menstrual cycles, reduced fertility, and increased stress hormone (cortisol) levels. Women’s bodies are more sensitive to energy deficits, and prolonged fasting can signal the body to conserve energy, potentially impacting reproductive health and overall well-being.

► Health status: Consider overall health, including metabolic health, hormonal balance, and stress levels. Fasting might not be right for you, if you’re pregnant, breastfeeding, or trying to conceive. Or if you have a history of eating disorders. High-stress individuals or those with poor sleep may need to be cautious with fasting.

Your Personal Fasting Plan: A Step-by-Step Guide

Embarking on a fasting journey can be transformative for your health and well-being. Regardless of which method you choose, here’s what I tell all my patients who want to start incorporating fasting into their longevity routines:

Step 1: Choose your start date

Select a specific day to begin your fasting journey. This helps mentally prepare you and allows for proper planning. Ensure it’s a day that aligns with your schedule, so you’re not immediately faced with social or work-related eating challenges.

Step 2: Start slowly with the 12/12 method

Begin with a manageable fasting approach like the 12/12 method, where you fast for 12 hours and eat during the remaining 12 hours. For example, have dinner by 6 PM and avoid any snacks afterward. This gradual approach can help minimize discomfort and make fasting more manageable.

Pre-planning your meals is crucial to ensure they are nutrient-dense, incorporating good-quality proteins, healthy fats, and plenty of vegetables to keep you satiated until the next meal. (Need inspiration? Check out my tried and true recipe collection.)

Step 3: Practice consistency

Regular fasting, rather than sporadic long fasts, can be more beneficial and sustainable. For many individuals, 12 to 16 hours of fasting are enough to reach and maintain their health goals.

Step 4: Listen to your body

Adjust fasting practices based on personal response, such as energy levels and hunger cues.

Step 5: Plan a nutritious breakfast

How you break your fast can significantly impact your fasting experience. So choose a breakfast that is balanced and nourishing to set a positive tone for the day. Avoiding sugary or highly processed foods is important when breaking your fast.

Here are some ideas you can try (curious about what I eat in a day?):

Omelet with your favorite vegetables (peppers, onions, kale, Brussels sprouts, etc.)
Hard-boiled eggs and an avocado.
Whole fat, grass-fed, non-dairy yogurt with nuts and berries.
Smoothie with spinach, protein powder, and flaxseeds (there are so many options)
Turkey patties with avocado-lime aioli (Don’t have time to make these for breakfast? Prep these the night before.)

Step 6: Eat nutrient-dense foods

Fasting doesn’t have to include caloric restriction. The primary focus should be on the timing of eating rather than the amount of food. Prioritize consuming whole, nutrient-dense foods during eating windows to ensure adequate intake of essential nutrients. This includes a balance of proteins, healthy fats, and complex carbohydrates.

Step 7: Stay hydrated

Men should drink about 15 cups per day, and women—11 cups. Hydration is essential for maintaining energy levels, aiding digestion, and supporting metabolic functions.

I always start my day by drinking at least 4 cups of water infused with electrolytes. These essential minerals play a crucial role in regulating key functions such as nerve and muscle activity, as well as maintaining proper hydration levels.

You can also include herbal teas and black coffee during fasting periods, but avoid adding sugars or creamers.

Step 8: Keep a fasting journal

Tracking your experience can provide insights and keep you motivated. In your journal, record:

Meals and fasting hours: Note what you eat and the duration of your fasting period.
Physical sensations: Track hunger levels, energy, and any physical changes.
Emotional responses: Reflect on your mood, stress levels, and overall mental well-being.
Progress towards goals: Regularly assess how you’re doing in relation to your initial fasting goals.

Step 9: Gradually extend fasting periods

As you become more comfortable with fasting, consider extending your fasting period. This could mean moving from the 12/12 method to a 16/8 approach, where you fast for 16 hours and eat during an 8-hour window. You can make gradual adjustments based on how your body responds and ensure it remains a sustainable part of your lifestyle.

By following this structured plan, you can start your fasting journey on the right foot, ensuring that it is both effective and sustainable. Remember, the key to successful fasting is consistency, patience, and being attuned to your body’s needs.

References

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Hailu KT, Salib K, Savithri Nandeesha S, Kasagga A, Hawrami C, Ricci E, Hamid P. The Effect of Fasting on Cardiovascular Diseases: A Systematic Review. Cureus. 2024 Jan 30;16(1):e53221. doi: 10.7759/cureus.53221. PMID: 38425626; PMCID: PMC10902743.
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Gudden J, Arias Vasquez A, Bloemendaal M. The Effects of Intermittent Fasting on Brain and Cognitive Function. Nutrients. 2021 Sep 10;13(9):3166. doi: 10.3390/nu13093166. PMID: 34579042; PMCID: PMC8470960.
Qian J, Fang Y, Yuan N, Gao X, Lv Y, Zhao C, Zhang S, Li Q, Li L, Xu L, Wei W, Wang J. Innate immune remodeling by short-term intensive fasting. Aging Cell. 2021 Nov;20(11):e13507. doi: 10.1111/acel.13507. Epub 2021 Oct 27. PMID: 34705313; PMCID: PMC8590100.
Ortega MA, Fraile-Martinez O, de Leon-Oliva D, Boaru DL, Lopez-Gonzalez L, García-Montero C, Alvarez-Mon MA, Guijarro LG, Torres-Carranza D, Saez MA, Diaz-Pedrero R, Albillos A, Alvarez-Mon M. Autophagy in Its (Proper) Context: Molecular Basis, Biological Relevance, Pharmacological Modulation, and Lifestyle Medicine. Int J Biol Sci. 2024 Apr 22;20(7):2532-2554. doi: 10.7150/ijbs.95122. PMID: 38725847; PMCID: PMC11077378.