What Is Intermittent Fasting?

INTERMITTENT FASTING: What Is It and What Are Its Benefits?

What Is Intermittent Fasting?

Intermittent fasting is a structured nutritional approach that focuses not on what you eat, but when you eat. It divides the day or week into eating periods and fasting periods.

The primary objective is to allow insulin levels to decrease for extended periods, thereby promoting metabolic adaptations. Intermittent fasting is not a diet plan; it is a meal timing strategy.

Types of Intermittent Fasting

1. 16:8 Method (Most Popular Model)

• 16 hours fasting

• 8-hour eating window
  Example: Eating between 12:00 PM – 8:00 PM

2. 14:10 Method

• More suitable for beginners

• Lower hormonal stress response

3. 5:2 Method

• Normal eating 5 days per week

• 500–600 kcal intake on 2 non-consecutive days

4. 24-Hour Fasting (Eat-Stop-Eat)

• Applied once or twice weekly

• Not recommended without professional supervision

Scientifically Observed Benefits

1. May Improve Insulin Sensitivity

Prolonged fasting reduces insulin levels, which may:

• Lower the risk of insulin resistance

• Facilitate fat oxidation

2. May Support Weight Management

Intermittent fasting:

• Enhances calorie awareness

• Reduces late-night snacking

However, weight loss only occurs with an overall calorie deficit.

3. May Enhance Metabolic Flexibility

Supports the body’s ability to switch efficiently between:

• Glucose

• Fatty acids

4. May Activate Cellular Repair (Autophagy)

Fasting may stimulate autophagy, a cellular renewal mechanism studied in aging and cellular stress research.

5. May Support Digestive Rest

Continuous food intake can burden:

• Gastric acid production

• Bile secretion

• Digestive enzymes

Structured fasting periods may reduce this load.

Who Should Avoid Intermittent Fasting?

Intermittent fasting is not suitable for:

• Pregnant or breastfeeding women

• Individuals with a history of eating disorders

• Type 1 diabetes patients

• Individuals sensitive to cortisol fluctuations

• High-performance athletes

Common Mistakes

• Overeating during the eating window

• Inadequate protein intake

• Ignoring electrolyte balance

• Forcing prolonged fasting

• Neglecting sleep and stress management

What to Eat During the Eating Window

• Adequate protein (1–1.2 g/kg body weight)

• High-fiber vegetables

• Healthy fats

• Complex carbohydrates

During fasting:

• Water

• Unsweetened herbal tea

• Black coffee

Conclusion

Intermittent fasting can be an effective nutritional strategy when personalized and applied correctly. It is not a universal solution but a metabolic tool that should be tailored to individual health status and lifestyle.