Intermittent Fasting 16:8 — Diets
Time-restricted eating pattern with 16-hour fasting and 8-hour eating windows, the most widely practiced and studied intermittent fasting protocol.
Overview
The 16:8 intermittent fasting protocol restricts daily food intake to an 8-hour window followed by 16 hours of fasting. This is the most commonly studied form of time-restricted eating (TRE). Multiple RCTs demonstrate benefits for weight loss, insulin sensitivity, blood pressure reduction, and inflammatory markers. The mechanism involves aligning nutrient intake with circadian metabolic rhythms and extending the daily fasting period to enhance fat oxidation and activate autophagy. A 2023 meta-analysis of 18 RCTs confirmed significant reductions in body weight, fat mass, and fasting glucose.
Indications
- Weight and fat mass reduction
- Insulin sensitivity improvement
- Blood pressure management
- Metabolic flexibility enhancement
- Circadian rhythm alignment
Mechanism of Action
Extended fasting depletes hepatic glycogen stores, shifting primary fuel utilization to fatty acid oxidation
Dosing
| Compound | Dose | Frequency | Notes |
|---|---|---|---|
| 16:8 Intermittent Fasting | 8-hour eating window | Daily | Common window: 12 PM - 8 PM; adjust to lifestyle |
| 14:10 Modified IF | 10-hour eating window | Daily | Gentler entry point; still provides metabolic benefits |
Safety & Contraindications
- May cause headaches, irritability, and difficulty concentrating during adaptation (1-2 weeks)
- Risk of overeating during the eating window if not mindful
- Contraindicated in type 1 diabetes, eating disorders, pregnancy, and underweight individuals
- May impair exercise performance if training during fasted state
- Medication timing may need adjustment (e.g., diabetes medications)