How long is it safe to fast?

If it’s your first time fasting, you may feel dizzy, tired, hungry, and irritated even during moderate fasting regimes. Yet, for newbies, the safe fasting method is either a 12 or 16-hour fast. Gradually, when you start feeling better and get used to these methods, you can shift to more challenging versions, like 24 or 48-hour fast. However, fasting times beyond 24 hours have increased physiological downsides and risks and are not necessary for weight and body fat reduction.

Is fasting for 14 hours effective?

Fasting for 14 hours is effective. It may provide positive effects on weight loss, cholesterol levels, blood pressure, and blood sugar. Combining the 14-hour fast with regular exercises and a balanced diet is beneficial for the aforementioned benefits.

What is the 12 12 fasting rule?

The 12:12 fasting method is perfect for beginners. Here’s how you do it: Choose a 12-hour overnight fasting period—for instance, 8pm to 8am Finish your meal before your eating window ends in the evening. During the fasting period drink enough water and other no-calorie beverages, like green tea or black coffee.

How many hours is considered fasting?

Abstaining from food for at least 12 hours counts as fasting. A 12-hour fast is an excellent method for newbies, as most of the fasting window occurs while you’re asleep.

What is the longest healthy fast?

The longest fast that has been researched and has not been found to have significant, unavoidable health drawbacks is 48 hours. Despite the possible benefits, this type of fasting is not recommended for beginners. Also, it has potential drawbacks, like feeling dizzy, exhausted, and sluggish, observed to a greater extent than with a shorter fast. To reduce the risks of a 48-hour fast, make sure you consume enough water, stay busy to prevent thoughts of hunger, and drink electrolytes.

Blog Editorial team Amanda Pasko, MS, MPH, RD

Amanda Pasko, MS, MPH, RD

MS in Nutritional Epidemiology from Harvard T.H. Chan School of Public Health

Amanda Pasko holds a Master’s in Nutritional Epidemiology from Harvard and a Master’s in Nutrition from the UNC Gillings School of Global Public Health. To her, it is rewarding to help others reach their goals, so she founded Athletic Peak Nutrition & Performance, a leading sports nutrition business.

Amanda has worked with diverse clients, including Olympic hopefuls, and serves as an Executive Contributor for BRAINZ Magazine and National Masters News. As an accomplished track & field athlete, she has won multiple world championships and international competitions. Amanda’s dedication to individualized nutrition plans stems from her belief in the power of science and personalized care to optimize health and performance. She takes joy in guiding others toward their aspirations and presenting health information in clear, relatable ways. In her spare time, Amanda aims to compete in track meets across all 50 states and visit every National Park in the US.

Experience

Founder & Owner of Athletic Peak Nutrition & Performance
Executive Contributor, BRAINZ Magazine
Contributor, Masters News
Executive Committee Member, USA Track & Field Women’s Commission
Meet Organizer, 2024 Ultra Multi-Event World Indoor Championships
WakeMed Hospital, Outpatient Nutrition Education Specialist

Education

Rice University, Bachelor of Arts, Kinesiology
Harvard T.H. Chan School of Public Health, Master of Science, Nutritional Epidemiology
UNC Gillings School of Global Public Health, Master of Public Health, Nutrition,
Academy of Nutrition and Dietetics, RD