Why Breakfast Isn't Necessarily the Most Important Meal of the Day

If you've explored health and fitness, you've probably come across variations of 'breakfast is the most important meal of the day,' 'eat breakfast to jumpstart your metabolism,' or even 'skip breakfast and suffer the consequences.' However, it turns out that these statements might not be entirely accurate.

My relationship with breakfast has been long and unpredictable. As a kid, I wasn't interested in it. But in 2010, I adopted a breakfast routine of oats and whey, which became the staple of my mornings. It felt almost like a religious ritual—each morning was marked by an offering to the 'gods of clean eating,' driven more by fear of a slower metabolism, muscle loss, and poor workouts than genuine love for it.

Then I delved deeper into fitness, experimenting with various routines and came across a method called 'Intermittent Fasting' (IF) on the Leangains blog. IF involves eating only during a brief window each day, fasting for the rest. This meant skipping breakfast. Initially skeptical, my research and experiments have led me to understand more about breakfast's actual role in a diet.

Why We Believe Breakfast Is Essential (And Why It Might Not Be)

Numerous studies emphasize the health benefits of breakfast, claiming it’s crucial for maintaining cardiovascular health, and that children who eat it tend to perform better academically. However, a closer examination reveals that most of these studies are observational. Rather than using controlled tests, they analyze existing data to make conclusions.

The issue lies in the complexity of bodily processes, which involve many different variables. For instance, could it be that children who regularly have breakfast come from wealthier families, which may explain their superior academic performance? Correlation does not equal causation.

Without a controlled environment, it is difficult to determine whether one factor is responsible for the observed results, or if the effects are mixed with other variables (though studying the human body in any other way is challenging).

An outdated belief, stemming from older research, is that eating several small meals throughout the day can 'boost metabolism.' This notion evolved into the idea that breakfast is the key to a healthy diet. The logic behind this is that, since you sleep for eight hours, your metabolism is inactive during that time, so you need breakfast to 'wake it up.' However, there's no solid evidence supporting this claim.

In the short term, varying meal frequencies can impact the Thermic Effect of Food (TEF), which refers to the energy used for digestion and nutrient absorption. However, over a full day, no significant difference is observed. In a study published in The British Journal of Nutrition, subjects eating three or six meals per day showed no difference in metabolism as long as their total caloric and nutrient intake remained the same.

What about the timing of meals? In a recent study published in The American Journal of Clinical Nutrition, researchers split participants into two groups: one that ate breakfast and one that skipped it. They instructed each group to stick to their assigned habit, either always skipping or always eating breakfast. After sixteen weeks, no notable weight loss occurred—just about a pound on average. Across the board, skipping or eating breakfast had no effect on weight. A similar twelve-week study also found no advantage to either skipping or eating breakfast for weight loss. The greatest weight loss was observed in groups that were instructed to change their habits.

In short, breakfast isn't all that significant. Except, of course, for pancakes, which are clearly the best. (And to the waffle lovers, do you really need extra pockets to hold more syrup?)

What I Learned from Skipping Breakfast

There are many myths surrounding intermittent fasting (IF), which involves cycling between fasting and eating periods, including skipping breakfast. As it turns out, the claims that skipping breakfast negatively affects cognition, metabolism, and so on are based on faulty observational studies. In fact, short-term fasting does not harm cognition, and it actually boosts metabolism through the release of catecholamines.

However, the real benefit I found in intermittent fasting is the freedom it gives dieters. Around 2010, when I first started experimenting with IF, I was pleasantly surprised. My metabolism didn't slow down, I didn't become overly hungry and overeat, and I certainly didn’t lose my progress, wither away, or suffer as the Internet had warned (thanks for nothing, Internet).

Because of the hormone ghrelin, which regulates your body's routine to eat at the same time every day, it took me about a week to adjust. After that, I noticed my mornings were more productive. I had one less thing to worry about. Instead of scrambling to cook eggs or oatmeal, I could train, read, or even hit snooze—no longer bound by the need to eat first thing.

This has been the case for many of my clients too. I've encouraged several trainees to try intermittent fasting (IF). It’s not a magic bullet for weight loss, but it helps them discover an eating pattern that fits their preferences, rather than strict rules. While many continue with the approach, others don’t. What matters most is showing that success isn’t about getting every tiny detail of your routine right—it’s about staying consistent.

So, should you skip breakfast? Do what works for you. If you enjoy breakfast, go ahead and eat it. If it doesn’t appeal to you, skip it—nothing bad will happen (just give yourself a week to adjust). Your choice should be based on personal preference and what you can stick to over the long term.

So, what’s the most important meal of the day? It’s any meal you choose it to be.

Images by Alvaro Tapia, Carmen Eisbar, and Polandeze.