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I woke this morning at my usual hour, around 5 a.m., made coffee with my new barista machine, and sat down with the latest studies that had come across my desk. A typical morning.

Then it was 7 o’clock — time to exercise. And here was the question: I wasn’t hungry. Coffee tends to blunt my appetite for a while. So should I eat breakfast before working out? Is coffee enough? And on mornings I’m not exercising, should I eat breakfast anyway?

We’ve all heard it: breakfast is the most important meal of the day. But is it? Where did that idea come from — science, tradition, or marketing?

Gail and I have a line we use several times a day: “Inquiring minds want to know.”

First, a better question

Here’s the problem I hit immediately. We can’t answer “is breakfast the most important meal” until we answer: most important for what?

Does breakfast uniquely help you lose weight? Give you energy to exercise? Keep you sharp at 10 a.m.? Get enough protein? Connect with people you love? A meal could be the champion of one and irrelevant to another.

So before I looked at a single study, I built a scoreboard — three questions:

1. Does breakfast change my body and health? (weight, blood sugar, disease risk, protein)
2. Does it help me perform today? (energy to exercise, mental sharpness)
3. Does it help me live well? (connection, family rhythm)

Two more considerations ride alongside: for whom — a hungry child, an endurance athlete, and an older adult chasing protein get different verdicts from the same meal — and compared to what? Skipping? A bigger lunch? Just coffee?

Where the slogan came from

“Breakfast is the most important meal” didn’t come from a medical breakthrough. It began at Dr. John Harvey Kellogg’s Battle Creek Sanitarium in Michigan — part spa, part hospital, part hotel. Kellogg may have been America’s first longevity guru; his gospel was “biologic living”: vegetarian, no alcohol, no coffee, lots of exercise.

Cereal itself was an accident. In the 1890s, cooked wheat left out overnight flaked when rolled — the first ready-to-eat flaked cereal. His brother W.K. saw the business in it, added sugar and salt over the doctor’s objections, and launched the company in 1906. A former patient, C.W. Post, copied the idea into Grape-Nuts.

The phrase itself came from dietitian Lenna Cooper, mentored by Kellogg, who wrote in his Good Health magazine in 1917 that breakfast “is the most important meal of the day, because it is the meal that gets the day started.” A reasonable health idea — which became a business.

Then in the 1920s, Edward Bernays — the father of public relations, and Freud’s nephew — was hired by Beech-Nut, whose key product then was bacon. Americans ate light: coffee and a roll. Bernays surveyed 5,000 physicians on whether a heartier breakfast was better. About 4,500 agreed. The result: “doctor-recommended” bacon and eggs.

But marketed doesn’t mean wrong. So let’s score it.

Question 1: Does breakfast change your body?

The strongest-sounding argument is observational, and it’s dramatic. In a nationally representative U.S. study of 6,550 adults followed 17 to 23 years, people who never ate breakfast had an 87% higher risk of dying from cardiovascular disease than daily breakfast eaters — even after adjusting for diet quality, lifestyle, BMI, and cardiac risk factors.

Case closed? Not quite. Breakfast skippers also tend to sleep less, smoke more, drink more, work irregular shifts, and eat late at night. People who do healthy things tend to do many healthy things. Skipping breakfast may be less a cause of illness than a marker of a more chaotic life. And in that same study, the rise in overall mortality wasn’t statistically significant.

So what happens when we randomize people? Conventional wisdom says eat breakfast to lose weight. But if breakfast adds calories without reducing them later, why would we expect that? A BMJ meta-analysis found adding breakfast didn’t help weight loss at all — breakfast eaters consumed more total daily calories, and skippers ended up slightly lighter. In reverse, same answer: a meta-analysis of seven trials found skipping breakfast produced about a pound of weight loss over two months. (Though skipping may nudge LDL cholesterol up — nothing is free.)

Breakfast’s best argument is timing. Insulin sensitivity is generally better earlier in the day, so the same food may be handled differently at 8 a.m. than at 10 p.m. In one well-controlled trial, men with prediabetes who ate all their food before 3 p.m. improved insulin sensitivity and blood pressure — without losing weight. Timing itself mattered. Other front-loading trials show modest extra weight loss, but the evidence is low-certainty. My honest read: the theory is elegant; the trials leave me uncertain. The villain may not be skipping breakfast — it may be saving calories for late at night.

One practical point: protein. If you need 90 grams a day, that’s harder if your first real meal is at noon.

Verdict: breakfast doesn’t change your body directly. Any effect runs through whether it helps you eat better across the whole day.

Question 2: Does breakfast help you perform?

For exercise, it depends on the job. A meta-analysis of 46 studies found eating beforehand improved prolonged aerobic performance — but not shorter sessions. For an easy 20–45 minutes, coffee and water are usually fine. For something long or hard, fuel matters. Caffeine improves performance, but caffeine is not fuel.

For the mind, the picture splits by whom. In children, a review of 36 studies found mostly positive effects on classroom behavior, with the clearest academic gains in undernourished kids. It’s hard to focus on fractions when you’re waiting for lunch. But in healthy adults, a review found only a small benefit for memory — and essentially nothing for attention or executive function.

Question 3: Does breakfast help you live well?

Food isn’t just fuel. The World Happiness Report 2025, using Gallup data from 142 countries, found that how often you share meals predicts wellbeing and loneliness about as strongly as income does. Roughly one in four Americans now eats every meal alone.

But that’s about shared meals — and for most of us, that meal is dinner. Dinner asks, how was your day? Breakfast asks, what’s ahead — are you ready?

Three questions, three different winners

Breakfast wins if your goal is earlier protein, circadian-friendly timing, fueling a hard morning workout, or a child’s readiness to learn. Lunch wins if your goal is afternoon focus and not arriving at dinner ravenous. Dinner wins if your goal is connection.

There is no single most important meal for everyone.

Here’s where I land. For me, breakfast is not the most important meal — but that’s not the same as “skip breakfast.” It depends on what the day asks of me. If I have a two-hour ride or run ahead, I eat; coffee alone won’t finish that workout. If I’m just writing and reading, coffee is enough. If I’m eating with friends or family, breakfast jumps to the top — the eggs are beside the point; the table is the point. And if nothing is pushing me toward breakfast, I skip it and save the calories until I’m genuinely hungry — though children, adolescents, pregnant women, and diabetics should be more cautious about skipping.

Maybe breakfast isn’t the most important meal of the day. Maybe it’s the most marketed. The most important meal is the one that helps you live the day you’re actually trying to live.

So — what do you think? For you, is breakfast the most important meal of the day?