Breakfast is often touted as the most important meal of the day, but doctors and experts in the field of longevity can't seem to agree on its significance.

Breakfast "can be an opportunity to get a lot of healthy foods into your body to start the day," longevity researcher Dan Buettner told CNBC Make It in January. "We have a saying, 'breakfast like a king, lunch like a prince and dinner like a pauper.'"

But some of the other experts I've interviewed don't seem to prioritize breakfast in the same way. In fact, many of them practice intermittent fasting — typically, eating within an eight-hour window and fasting for 12 to 16 hours — which can mean they aren't having that first meal until long after their day has started.

"I always skip, or very often skip, breakfast," Dr. Andrea Maier, who has almost 25 years of experience in geroscience, told Make It in October. "I really start eating at two o'clock [p.m.], three o'clock. Sometimes my first meal is in the evening, and I'm fine."

Can skipping breakfast impact your health?

Opinions on the effects of breakfast on one's health and longevity are pretty mixed. People who skip breakfast may have a higher risk of death from any cause, especially cancer, according to a 2021 study published in the journal Cancer Causes & Control.

But Dr. Peter Attia, a physician and longevity researcher, pointed out that the study also found that people who don't eat breakfast are less health-conscious in general, compared to those who eat breakfast regularly.

"The seemingly reduced all-cause and cancer mortality risk among persons who consume breakfast every day may simply be the reflection of habitual breakfast consumption being a proxy for a health-conscious lifestyle," the 2021 paper states.

This makes it difficult to determine if skipping breakfast has an impact on longevity or if it's due to lifestyle choices like smoking, Attia explained. Breakfast skippers were nearly three times as likely to smoke cigarettes than breakfast eaters, according to that same study.

But even if skipping breakfast doesn't directly affect your ability to live a long, healthy life, research shows it may not be the best choice for your mood and quality of sleep.

Not eating breakfast was associated with an alteration of sleep chronotypes and an increase in depressive symptoms which led to worse sleep quality, according to a 2023 study with over 700 college students. Though skipping the meal didn't significantly affect sleep, there was a noticeable difference in comparison to the sleep quality of people who ate breakfast often, researchers noted.

Another study published in 2019 found similar effects. The small study with 66 healthy participants in their 20's found a possible connection between breakfast consumption frequency and mood, sleep quality and eating habits.

People who ate breakfast regularly had a "better perceived sleep quality, mood upon waking, and alertness upon waking compared to those that skip breakfast," according to the study. Getting good quality sleep is one of the practices that can up your chances of living longer, and the longest-living people tend to have more positive attitudes.

If better sleep and a better mood is important to you, then consider making breakfast a part of your morning routine.

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