Time Restricted Fasting
History
Documentation of fasting in the historical record goes as far back as ancient Egypt. In practice, a multitude of various civilizations over the last few centuries used it. Religious and cultural groups integrated fasting for ritualistic purification and spiritual enlightenment. Now, persisting, it continues in Christianity, Islam, Judaism, Hinduism and Buddhism. These social, religious, cultural and metaphorical interpretations of fasting show wellness. Science today is able to give us reason for fasting health benefits.
The definition of fasting is abstaining from food. The time duration can vary depending on individual need.
Fasting can be categorized into variable time duration, each with its own potential benefits and effects on the body. Here are some common types.
- Intermittent Fasting (IF): This involves cycling between periods of eating and fasting. Common methods include:
- 16/8 Method: Fasting for 16 hours and eating during an 8-hour window.
- 12/12 Method: Fasting for 12 hours and eating during a 12-hour window.
- 5:2 Method: Eating normally for five days and restricting calorie intake to about 500-600 calories on two non-consecutive days.
2.Extended Fasting:
- 24-Hour Fast: Fasting for a full 24 hours.
- 36-Hour Fast: Fasting for 36 hours, usually done from dinner one day to breakfast two days later.
- 48-Hour Fast: Fasting for two full days.
3. Alternate-Day Fasting (ADF): Alternating between days of regular eating and days of fasting or very low-calorie intake.
4. Extended Fasting (Multi-Day Fasting):
- 3-Day Fast: Fasting for three consecutive days.
- 5-Day Fast: Fasting for five consecutive days.
- 7-Day Fast: Fasting for a full week.
5. Time-Restricted Eating: Similar to intermittent fasting, this approach involves restricting the daily eating window but can be more flexible in duration, such as eating within a 10-hour window.
6. Spontaneous Fasting: Occurs when you skip meals or unintentionally go without food for an extended period.
The choice of fasting duration depends on individual goals, preferences, and health considerations. .
The effect of fasting based on duration is a complex topic. For the sake of simplicity the discussion will revolve around the sixteen hour fast, specifically targeted for during sleeping hours with an eating window of 5-8 hours. Shorter fasting windows, like intermittent fasting, can be easier to incorporate into daily routines, while longer fasts require careful planning and monitoring, and they might be more suitable for experienced fasters.
Energy Storage and Usage
In order to achieve this we need to understand how the body stores energy and then mobilizes it for use. There are two primary sources of energy within the body, glucose and fat. Our bodies have evolved to store glucose in the form of glycogen (long chains of glucose) in the liver and muscles.
Once we deplete glycogen, usually after 16-18 hours of fasting, our bodies start using fat stores and gluconeogenesis to make glucose. This switches the body into a catabolic process where glucose is made in the liver using amino acids and fat break down products. But fasting is not the only way fat loss occurs, the alternate pathway is moderate intensity exercise with the heart rate in the 50-70% zone, a discussion for another time.
Flipping this metaphorical body switch turns on variable metabolic, hormonal and cellular mechanisms beneficial for healthy living.
List of Health Benefits
1. It enhances defense against oxidative stress. It triggers autophagy, where it removes damaged cells and recycles components. Clearance of toxins and dysfunctional cellular structures, promoting cellular health.
2. It can extend a healthy lifespan. Some forms of fasting have been associated with the activation of Sirtuins, a group of proteins involved in regulating cellular processes that influence aging and longevity.
3. Improves metabolism and reduces blood glucose. Can improve insulin sensitivity and reduce insulin resistance. Fasting lowers insulin levels consistently, switching on the mechanism for fat catabolism (fat loss)
4. Beneficial for chronic inflammation which is linked to various age-related diseases. Reducing it may contribute to a longer, healthier life.
5. Burns fat between meals. The long-term effects of fat loss are reduction in blood pressure, joint and cardiovascular health.
6. It enhances stress tolerance. The production of brain-derived neurotrophic factor (BDNF), a protein that supports the growth and maintenance of nerve cells, increases with fasting. BDNF is associated with improved cognitive function, mood regulation, and enhanced stress coping abilities.
7. Turns on clock genes. These genes help our body control mechanisms which help with sleep, hunger, mood, and health.
8. Fasting may promote DNA repair. Maintain Telomeres, the protective caps on the ends of chromosomes.
9. Increases growth hormone production. This increases utilization of fat for energy, safeguards bone density and preserves muscle mass.
10. The adrenaline effect. Adrenaline levels rise during fasting to provide energy, and even extended fasting boosts metabolic rate. Fasting induces hormonal adaptations beneficial for the body, transitioning from sugar to fat burning, without reducing resting metabolism.
Fasting, a practice with historical roots spanning centuries, taps into our innate survival mechanisms that evolved to cope with extended periods of food scarcity. These mechanisms not only helped us endure but also sharpened our cognitive and physical faculties to secure sustenance. Ongoing research delves into these cellular processes, holding the promise of unveiling more about their potential benefits. By leveraging these built-in adaptations, we can aim for an improved healthy life.