Intermittent fasting (IF) has gained significant attention in recent years as a popular approach to improving health and managing weight. Many praise its ability to promote weight loss, enhance metabolic health, and reduce inflammation, while others caution against potential drawbacks like fatigue, nutrient deficiencies, and fasting-related discomforts. This discussion explores both the benefits and challenges of intermittent fasting, offering a balanced perspective on whether this eating pattern is a sustainable choice for individuals looking to optimize their health.

What is intermittent fasting?

Intermittent fasting is an eating pattern that switches between periods of eating and fasting. These periods of fasting usually leave an 8 hour window to eat, which means 16 hours of fasting; however, individuals may opt for different variations, such as a 17-hour fasting period with a 7-hour eating window or other customized schedules. Unlike most diets, IF focuses on when to eat, rather than what to eat. 

Pros 

Intermittent fasting is most commonly known for its extensive weight management benefits. Cycling between fasting and eating periods is essentially what allows the body to transition its reliance on fat for energy, which leads to preservation of muscle mass and reduction in body fat percentage. 

IF has also been shown to significantly improve metabolic health through multiple modes.

• Extended periods without food helps stabilize blood sugar levels because of the utilization of stored glucose and prevention of erratic spikes. This stabilization supports glycemic control making it beneficial for those at risk of type 2 diabetes. 
• Insulin levels will have an overall decrease as well because IF enhances insulin sensitivity (the body requires less insulin to transport glucose into cells for energy). This decrease helps in countering insulin resistance, a prominent feature of metabolic syndromes and diabetes.

Chronic inflammation occurs when the immune system is persistently activated, due to factors like stress, a poor diet, stress, lack of physical activity, etc… Intermittent fasting has been shown to reduce chronic inflammation by making levels of pro-inflammatory markers such as C-reactive protein (CRP) and cytokines lower. Being in a state of fasting gives the body a chance to clean itself up and reset by focusing on processes such as autophagy, a cellular cleanup mechanism that removes damaged cells and reduces oxidative stress (key driver of inflammation). 

Cons

Because IF leads to different glucose levels at different times during the day depending on the schedule you follow, one may experience fatigue and decreased energy levels that can interfere with daily activities. Additionally, under extended periods of fasting combined with a lack of nutrients when eating malnutrition may occur. To avoid this risk, it is vital to include foods that will fuel you during the timings that you will be eating. Including complex carbohydrates like sweet potatoes and brown rice or healthy fats like avocados and proteins such as chicken, tofu, and eggs are beneficial and will help with reducing low energy levels during the fasting period. 

A fasting headache may result from any type of fasting but its occurrence is positively correlated with the duration of the fast. These headaches can be especially observed in those who become hypoglycemic or experience caffeine withdrawal and usually resolve within 72 after food intake. It is important to decrease caffeine intake in increments leading up to the start of your intermittent fasting in order to avoid experiencing symptoms associated with caffeine withdrawal as well as remain cautious of the amount of time you are fasting. 

So… what’s the bottom line?

Intermittent fasting is a method that fits very easily into most people’s schedules due to its varied flexibility. By prioritizing nutrient-dense meals, staying properly hydrated, and listening to your body’s needs, you can maximize the benefits of IF while minimizing the downsides. So if done with consideration and balance, intermittent fasting can improve your overall well-being. However, if you have any preexisting health conditions, it is always advisable to consult with a healthcare provider before starting IF, or any new diet, to ensure it is a safe and suitable option.

Sources

Academy of Nutrition and Dietetics. (2019). Eatright.org – Academy of Nutrition and Dietetics. Eatright.org. https://www.eatright.org/

Harvard Health Publishing. (2019, July 31). Not so fast: Pros and cons of the newest diet trend – Harvard Health. Harvard Health; Harvard Health. https://www.health.harvard.edu/heart-health/not-so-fast-pros-and-cons-of-the-newest-diet-trend

Harvard T.H. Chan. (2012, September 18). Carbohydrates. The Nutrition Source. https://nutritionsource.hsph.harvard.edu/carbohydrates/

Intermittent Fasting and Inflammation. (2019, August 22). Healthline. https://www.healthline.com/health-news/fasting-can-help-ease-inflammation-in-the-body#The-best-ways-to-fast

Miller, S. (2022, May 27). Intermittent Fasting and Insulin Resistance: Benefits Beyond Weight Loss. Www.jeffersonhealth.org. https://www.jeffersonhealth.org/your-health/living-well/intermittent-fasting-and-insulin-resistance-benefits-beyond-weight-loss

Patterson, R. E., Laughlin, G. A., LaCroix, A. Z., Hartman, S. J., Natarajan, L., Senger, C. M., Martínez, M. E., Villaseñor, A., Sears, D. D., Marinac, C. R., & Gallo, L. C. (2015). Intermittent Fasting and Human Metabolic Health. Journal of the Academy of Nutrition and Dietetics, 115(8), 1203–1212. https://doi.org/10.1016/j.jand.2015.02.018

Torelli, P., & Manzoni, G. C. (2010). Fasting Headache. Current Pain and Headache Reports, 14(4), 284–291. https://doi.org/10.1007/s11916-010-0119-5