What’s Better: Eating Breakfast vs Intermittent Fasting?

The answer is more complicated than it seems. While initially, common advice from nutritionists suggested that skipping breakfast and lengthening your fast would yield more positive results, a recent study has shown there is a better way to achieve weight loss, improve sleep cycles, and improve metabolism.

To maximize the positive benefits of intermittent fasting, eat an early breakfast (before 8:30 a.m.) and an early dinner (between 4 p.m. and 5 p.m.).

Interested in learning why? Dive into the latest research below.

The Goal of Intermittent Fasting

Fasting and intermittent fasting is nothing new. According to Encyclopedia Britannica, medical fasting dates at least as far back as the Greek physician Hippocrates, 5th century BCE. (The same physician behind the famous oath all doctors take: Do no harm). Organized research on the physiological effects of fasting occurred in the late 19th century. Since then, fasting methods have become more and more sophisticated as our understanding of the body’s processes around food consumption and absorption has evolved.

Intermittent fasting is a type of fasting that has grown in popularity due, in part, to the relative ease of doing it daily. It has become a popular option with some of our nutrition patients. By shrinking the time you consume food to, most commonly, an 8-hour window, you allow your body to enter a fasting state for the time in between. This has consistently shown a reduction in insulin resistance, which is directly correlated with improved weight management and the reversal of diabetes and other metabolic dysfunctions. Most people will choose to fast around 16 hours overnight, finishing dinner at 6 or 7, then breaking their fast at 10 or 11 a.m. the next day. Although this strategy will get results when done effectively and consistently, new research suggests it may not be an optimal strategy.

Why Intermittent Fasting is More Complicated Than It Seems

A new study presented in March 2021 at The Endocrine Society’s annual meeting examined fasting blood sugar levels and survey data for over 10,000 participants. They were specifically looking to see how fasting blood sugar levels and estimated insulin resistance were affected by different eating/fasting windows. As expected, those that fasted the longest did have lowest insulin resistance or best outcome. But people who ate their first meal before 8:30 a.m. also showed lower insulin resistance, regardless of whether they restricted eating to less than 10 hours or spread their meals out over greater than 13 hours.

These findings suggest that eating early in the morning (before 8:30 a.m.) may be another important habit linked with improving metabolism. This most recent research joins others investigating our fluctuating and differing hormone production associated with wake/sleep cycles and their impact on our metabolism. So, while the practice of intermittent fasting continues to show improved effects on metabolism, adjusting your fasting window to finish dinner between 4 and 5 p.m. might produce even more powerful results.

So what’s better?

An early dinner.

Online Nutrition Counseling: Expert Advice on Intermittent Fasting

It’s important to note that intermittent fasting may not be right for everyone, depending on your age, health, and fitness goals. A registered dietitian can help you discover the right nutrition plan for you.

If you have specific questions about intermittent fasting, feel free to schedule an online appointment with one of our expert dietitians today.

Authored by:

Caroline Pope, MS, RDN, LDN

Caroline Pope began practicing as a Registered Dietitian in 2015 after completing her Master of Science in Nutrition from Meredith College and her Bachelor of Arts in Psychology from UNC Chapel Hill.

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