How long should you fast and eat?
Intermittent fasting 16/8 means 16 hours of fasting and 8 hours for eating.
Basic Rules
You need to choose a time frame for eating that fits conveniently into your daily routine. For example, you can eat from 12:00 PM to 8:00 PM or from 10:00 AM to 6:00 PM.
During the remaining 16 hours, you must refrain from eating, but you are allowed to drink water, black coffee, or tea without sugar.
Health Impact
Studies show that intermittent fasting 16/8 can positively affect blood sugar levels and lipid profiles. For instance, it helps reduce glucose levels and improve lipid metabolism in adults [1].
It has also been noted that this eating pattern may help reduce inflammatory processes and improve cardiovascular health [2].
How to Properly Conduct Intermittent Fasting 16/8?
The goal of intermittent fasting 16/8 is to improve metabolism and control weight. This method involves 16 hours of fasting and 8 hours for eating.
Steps for Conducting 16/8
- Determine your eating window, for example, from 12:00 PM to 8:00 PM.
- During the 8 hours, eat balanced meals rich in nutrients, including proteins, carbohydrates, and fats.
- Drink enough water throughout the day to maintain hydration levels.
Expectations and Safety
Realistic expectations include gradual weight loss and improved metabolic markers. It is important to remember that individual responses to fasting may vary, so pay attention to how you feel.
Before starting the practice, consult with a doctor, especially if you have chronic conditions. Some studies suggest that intermittent fasting may not be suitable for everyone [1][3].
What is Intermittent Fasting 16/8 and How Does It Work?
Intermittent fasting 16/8 is a dietary regimen where you do not eat for 16 hours and are allowed to eat for 8 hours each day. This is usually achieved by skipping breakfast and limiting food intake from 12:00 PM to 8:00 PM.
Simple Physics
The main principle of intermittent fasting is to create a caloric deficit, which promotes weight loss. During fasting, insulin levels decrease, allowing the body to use fat stores as an energy source.
Intermittent fasting can help control overall calorie intake since you have less time to eat. This can lead to a natural reduction in caloric intake without the need for strict diets.
Mechanism of Action
Intermittent fasting 16/8 improves insulin sensitivity and lowers blood glucose levels. This can be particularly beneficial for individuals predisposed to diabetes or metabolic disorders.
Moreover, studies show that this eating pattern can improve lipid profiles by lowering triglycerides and total cholesterol [1][3]. This creates conditions for improving overall health and reducing the risk of cardiovascular diseases.
Risks and Caution with Intermittent Fasting 16/8
Intermittent fasting 16/8 may not be suitable for everyone. People with certain conditions, such as uncontrolled diabetes, should be particularly cautious. In such cases, it is important to consult with a doctor before starting the practice.
Possible Side Effects
Some side effects may occur while following the 16/8 regimen, including:
- Dizziness
- Fatigue
- Eating disorders
These symptoms may arise in the initial stages as the body adapts to the new eating pattern.
Monitoring Health Status
It is important to monitor your health during the practice of intermittent fasting. If you notice a decline in well-being or the emergence of new symptoms, you should:
- Consult a doctor.
- Adjust your fasting approach.
- Assess the need to change your eating regimen.
Regular check-ups and tests can help avoid negative consequences and tailor the method to your individual needs.
Comparison of Intermittent Fasting Methods 16/8
| Method | How it Works | Who It's Suitable For | Cons |
|---|---|---|---|
| 16/8 TRE | Fasting for 16 hours, eating for 8 hours | Those who want to control weight and improve metabolism | May be difficult to adhere to at first |
| Alternate Day Fasting | Alternating days of fasting and regular eating | Those who prefer flexibility in their diet | May lead to overeating on eating days |
| 5:2 Method | Caloric restriction to 500-600 on 2 days a week | Those looking for a less strict approach to fasting | Not suitable for people with high levels of physical activity |
| Super Fasting | 24-hour fast once a week | Those who want to lose weight quickly | May lead to fatigue and decreased energy |
This diagram illustrates subjective assessments of the effects of intermittent fasting 16/8 across various health parameters. The ratings are based on data from several studies and are conditional.
Common Questions
What is Intermittent Fasting 16/8?
Intermittent fasting 16/8 is a dietary regimen where you fast for 16 hours and eat for 8 hours. This usually means skipping breakfast and eating only between 12:00 PM and 8:00 PM.
What are the benefits of Intermittent Fasting 16/8?
Benefits include weight loss, improved metabolism, reduced blood sugar levels, and improved lipid profiles [1][2]. Positive changes in body composition and reduction of inflammatory processes have also been observed [4].
How long should you fast and eat?
Under the 16/8 method, you fast for 16 hours and eat during 8 hours. This can be adapted to your habits, but the classic approach implies that the main meal occurs in the middle of the day and in the evening.
Who should avoid this fasting method?
This method is not recommended for people with certain conditions, such as diabetes, as well as for pregnant and breastfeeding women. It is advisable to consult a doctor before starting [3][5].
How does intermittent fasting affect blood sugar levels?
Research shows that intermittent fasting can help lower blood sugar levels and improve insulin sensitivity, which is especially important for people with prediabetes or type 2 diabetes [3][6].
Intermittent fasting 16/8 includes 16 hours of fasting and 8 hours for eating.
This material is for informational purposes only and does not replace medical consultation. For chronic conditions, pregnancy, medication, or concerning symptoms, make decisions in consultation with a specialist.
References
- [1] Wong PS, et al. Effect of 8-Hour Time-Restricted Eating (16/8 TRE) on Glucose Metabolism and Lipid Profile in Adults: A Systematic Review and Meta-Analysis. Nutr Rev. 2026. PMID: 41351878. https://doi.org/10.1093/nutrit/nuaf206 PubMed
- [2] Moro T, et al. Effects of eight weeks of time-restricted feeding (16/8) on basal metabolism, maximal strength, body composition, inflammation, and cardiovascular risk factors in resistance-trained males. J Transl Med. 2016. PMID: 27737674. https://doi.org/10.1186/s12967-016-1044-0 PubMed
- [3] Chen J, Liu P, Wang M, Yan X, Li J, Guo J. Efficacy of intermittent fasting on blood glucose and weight in type 2 diabetes and prediabetes: A comparison with ad libitum and continuous energy restriction diets. Asia Pacific journal of clinical nutrition. 2026. PMID: 42242847. https://doi.org/10.6133/apjcn.202606_35(3).0003 PubMed
- [4] Pappe CL, et al. Intermittent Fasting Regimes Reduce Gingival Inflammation: A Three-Arm Clinical Trial. J Clin Periodontol. 2025. PMID: 40059409. https://doi.org/10.1111/jcpe.14151 PubMed
- [5] He H, Qin Z, Liu K, Wang Z, Wang J. The effects of intermittent fasting on BMI, fasting blood glucose, and blood pressure in women with overweight or obesity: a systematic review and meta-analysis with dose-response relationships. Frontiers in nutrition. 2026. PMID: 42221756. https://doi.org/10.3389/fnut.2026.1818813 PubMed
- [6] Wu X, Ding Y, Cao Q, Huang J, Xu X, Jiang Y, Xu Y, Lu J, Xu M, Wang T, Zhao Z, Wang W, Ning G, Bi Y, Li M. Comparison of Different Intermittent Fasting Patterns or Different Extents of Calorie Restriction for Weight Loss and Metabolic Improvement in Adults: A Systematic Review and Network Meta-Analysis of Randomized Controlled Trials. Nutrition reviews. 2026. PMID: 40367516. https://doi.org/10.1093/nutrit/nuaf056 PubMed