“Breakfast is the most important meal of the day.” Most of us have heard that line since childhood—from parents, at school, in cereal ads, or in lifestyle magazines. It sounds sensible and safe, almost like a universal rule of healthy living. But when you take a closer look at where this slogan came from and what scientific studies actually say, the picture is far less clear-cut—and far more entangled with marketing and money than with pure science.
Picture a typical morning: you’re rushing to work, you’re not hungry, but a nagging sense of guilt flashes in your head—“I should eat something; they say it’s the most important meal of the day.” In this article, we’ll look at how breakfast became a moral and health “must,” what modern research says about it, and why it may be smarter to stop believing simple slogans and start listening more to your body and your overall lifestyle.
How the “most important meal of the day” slogan was born
Before the end of the 19th century, neither in the U.S. nor in Europe did people talk about breakfast as “the most important meal of the day.” In the morning, people ate whatever was available—often leftovers from dinner—and this meal had no special status. The turning point came with the Industrial Revolution, changing work schedules, and, crucially, the rise of the food industry, which needed to sell new products. Food historians note that this is when the first breakfast cereals emerged in Seventh-day Adventist–associated sanitariums, linked to names like James Caleb Jackson and John Harvey Kellogg.
As a The Guardian article describes how lobbyists and food manufacturers “made” breakfast the most important meal of the day, breakfast gradually became moralized: it was presented as a sign of discipline, a hard-working character, and a “proper” lifestyle. Legendary PR campaigns played a role too—for example, Edward Bernays, working for Beech-Nut, promoted “scientifically recommended” bacon and eggs by having thousands of doctors sign a statement that a heavier, protein-rich breakfast was “healthier” than a light meal. It then appeared in newspapers as if it were objective scientific truth, not clever marketing.
From the 1940s onward, breakfast cereals started being fortified with vitamins, and ads portrayed a bowl of cereal as a magical combination of all the nutrients children needed. Emotional pressure on parents entered the picture as well: “If you want to be a good parent, give your child a nutritious breakfast—and that is, of course, our cereal.” In an industry that moves billions of euros a year, a very powerful narrative gradually took hold: if you don’t eat breakfast “properly,” you’re jeopardizing your health, your performance, and even your moral standing. The punchline is that this line wasn’t invented by an independent scientist, but by people whose main goal was to sell more food.
Breakfast between marketing and science: why the data are so contradictory
If you look at older epidemiological studies, breakfast seems genuinely great: people who eat breakfast often have a lower BMI, a better lipid profile, smoke less, and generally lead a “healthier” lifestyle. The problem is that these are observational studies—they can show an association, but not causation. Harvard Health notes that breakfast eaters are more often from higher socioeconomic backgrounds, have more regular routines, more stable working conditions, and better access to healthcare. All of that strongly affects health, but it can’t easily be separated from breakfast itself.
Another issue is that “breakfast” doesn’t always mean the same thing in studies. One person eats oatmeal with nuts and fruit; another eats sugary cereal high in sugar with very little protein. From a scientific standpoint, it’s a major oversimplification to say breakfast, as such, is automatically healthy or unhealthy. In reality, it depends on what exactly you eat, when you eat it, and how it fits into the overall context of your day.
That’s why Harvard Health talks more about “breakfast as an opportunity,” not as a magical tool. For many people, morning is a convenient time to add fiber, quality protein, and healthy fats—but if someone naturally isn’t hungry in the morning and eats a balanced diet overall, science so far provides no reason to believe that skipping breakfast by itself will automatically harm their health.
Breakfast, weight loss, and metabolism: what clinical trials found
The myth that breakfast “kick-starts your metabolism” and that without it your body switches into “fat-storage mode” sounds nice, but modern clinical studies don’t strongly support it. One of the most cited papers, published in 2014 by Emily J. Dhurandhar et al. in the American Journal of Clinical Nutrition, was a randomized controlled trial with 309 overweight or obese adults. Participants were randomly assigned to three groups: one was told to eat breakfast, another to intentionally skip it, and a third served as a control group. After 16 weeks, the recommendation to eat or not eat breakfast had no measurable effect on weight loss.
Harvard Health also reports on a meta-analysis of 13 randomized trials examining the effect of breakfast on weight and energy intake. The average result surprised many: participants who ate breakfast tended to weigh slightly more after several weeks than those who skipped it, and they also consumed about 260 more kcal over the course of the day. That directly challenges the popular idea that if you skip breakfast, you’ll inevitably “raid the fridge” at night.
The practical takeaway is fairly straightforward: if you love breakfast and it helps you feel good, go ahead and enjoy it—but don’t expect that the mere fact of eating breakfast will guarantee weight loss. If, on the other hand, you’re not hungry in the morning, there’s no high-quality evidence that should force you to eat just because “you’re supposed to.” What matters is total energy intake, food quality, and whether you can maintain a healthy routine long term—not whether your first calories come in at 7:00 or 11:00.
Breakfast and cardiovascular health: where marketing ends and caution begins
From a slightly different angle, studies tracking cardiovascular disease and mortality look at breakfast. A systematic review and meta-analysis of prospective cohort studies published by Ofori-Asenso et al. in 2019 analyzed nearly 200,000 adults with no known cardiovascular disease at baseline. People who regularly skipped breakfast had about a 21% higher risk of developing cardiovascular disease or dying from it, and a 32% higher risk of death from any cause compared with those who ate breakfast.
That sounds dramatic, but the authors themselves highlight major limitations. The definition of “skipping breakfast” differed across studies, measurement was often based on questionnaires, and adjustment for various confounders (smoking, alcohol intake, physical activity, socioeconomic status) was not consistent. In other words, people who don’t eat breakfast also more often sleep less, smoke more, eat more ultra-processed foods, and exercise less—and these factors may be the real reason for the higher risk, not the mere fact that they don’t eat in the morning.
In recent years, more meta-analyses have suggested that breakfast may be associated with a lower risk of hypertension or metabolic syndrome, but the same caveat applies: these are mostly observational data. Whether the advice “always eat breakfast” should be universal prevention for cardiovascular disease is still debated among evidence-focused clinicians. It’s more reasonable to view breakfast as one piece of the puzzle, not a magical talisman.
Who breakfast actually helps—and who it may not suit
If we ignore the advertising slogans, one simple question remains: who does breakfast genuinely benefit, and who does it get in the way of? In children and adolescents, there’s a fair amount of evidence that regular breakfast may be linked to better concentration at school, a more stable mood, and a lower tendency to reach for energy-dense, nutrient-poor snacks. Their bigger issue is often replacing breakfast with a sugary drink or sweet pastries, which can provide short-term energy but lead to the classic “crash” an hour later.
For adults, the situation is far more individual. Some people are naturally hungry in the morning, it fits their work schedule better, and breakfast serves as a pleasant anchor to the day. Others—especially those practicing different forms of intermittent fasting—feel better when they delay their first meal until lunch. Rigid insistence that “everyone must eat breakfast” often leads, in practice, to people grabbing something quick, cheap, and highly processed—just to feel like they’ve met an “obligation.”
A specific group includes people with certain diagnoses—for example, people with diabetes, patients taking certain medications, or pregnant women—where meal timing and composition, including breakfast, can have concrete medical significance. In those cases, the final word should come from the treating physician or a registered dietitian, not an internet article. Generally, though, a healthy adult can set up a routine that suits them—not one that suits marketing.
How to build a solid breakfast, if you do eat in the morning
If you’re among those who are hungry in the morning—or simply feel better with breakfast—it’s worth thinking more about quality than about the mere existence of breakfast. Experts at Harvard Health recommend focusing on a combination of complex carbs (for example, oats or whole-grain bread), quality protein (eggs, Greek yogurt, quark, legumes), and healthy fats (nuts, seeds, avocado). This kind of breakfast keeps you full longer, stabilizes blood sugar, and reduces the chance you’ll end up at the vending machine for sweets two hours later.
By contrast, the classic “kids’ bowl” packed with sweetened cereal, minimal fiber, and a splash of milk is exactly what many doctors and nutrition experts point to as a problem: lots of fast sugars, little protein, few micronutrients, and hunger returning soon after. Ironically, this is the type of breakfast most aggressively marketed as “the most important meal of the day.” Whether you eat breakfast or not, try to make your first (and really every) meal more like “real food” made from whole ingredients—not just a product polished up by marketing.
If you don’t feel like eating in the morning, a glass of water, unsweetened tea, or coffee often helps, and you can delay your first meal until you’re genuinely hungry. From the standpoint of a healthy person, there’s no reason to force yourself to eat just because ads drilled it into your head.
What it means for the average person
When you put the historical facts and modern research together, the conclusion is fairly moderate. The slogan “breakfast is the most important meal of the day” was created and kept alive for years thanks to highly successful marketing campaigns by cereal and meat producers, not as the result of a strong scientific consensus. Modern randomized studies have not shown that the simple advice “eat breakfast” leads to meaningful weight loss; if anything, they suggest breakfast is not a magical metabolic starter that protects you from obesity.
On the other hand, long-term observational studies suggest that people who completely ignore breakfast may have a slightly higher risk of cardiovascular disease and mortality, though this may reflect an overall less healthy lifestyle rather than a direct effect of skipping a single meal. The truth is somewhere in the middle: breakfast is neither a magical elixir without which you’ll die, nor a meaningless detail you can ignore regardless of context.
For the average person, it makes sense to follow two simple principles. First, listen to your body—if breakfast benefits you, helps you feel better, and you can keep it in a healthy form, there’s no reason to cut it out just because some intermittent-fasting trend is having a moment. Second, look at your diet as a whole: food quality, variety, fiber, protein, vegetables and fruit, movement, sleep, and stress likely have a much bigger impact on your long-term health than the question of whether your first bite of the day happens at 8 a.m. or 11 a.m.
Video: Why cereal makers love breakfast so much
If you prefer video to text, this (English-language) clip explains very clearly how breakfast became a marketing myth and why the slogan “the most important meal of the day” sells so well.
Video: Is breakfast important for weight loss? A look at the scientific studies
In this video, you’ll find an overview of research on what eating breakfast does (or doesn’t do) to body weight, energy intake, and overall health—again in English, but with plenty of practical examples.
Video: The “you must eat breakfast” myth—explained by a doctor
A short expert video explaining why the recommendation “eat breakfast at all costs” isn’t universal and why eating should be tailored to the individual.
Sources
- Olga Oksman – How lobbyists made breakfast “the most important meal of the day” – The Guardian, 2016.
https://www.theguardian.com/lifeandstyle/2016/nov/28/breakfast-health-america-kellog-food-lifestyle - Monique Tello – Eating breakfast won’t help you lose weight, but skipping it might not either – Harvard Health Publishing, 2019.
https://www.health.harvard.edu/blog/eating-breakfast-wont-help-you-lose-weight-but-skipping-might-not-either-2019041916457 - Emily J. Dhurandhar et al. – The effectiveness of breakfast recommendations on weight loss: a randomized controlled trial – American Journal of Clinical Nutrition, 2014.
https://pubmed.ncbi.nlm.nih.gov/24898236/ - Raymond Ofori-Asenso et al. – Skipping breakfast and the risk of cardiovascular disease and death: a systematic review of prospective cohort studies in primary prevention settings – Journal of Cardiovascular Development and Disease, 2019.
https://pubmed.ncbi.nlm.nih.gov/31443394/
Jana
I like turning curiosity into words, and writing articles is my way of capturing ideas before they slip away — and sharing them with anyone who feels like reading.
