Breakfast: The Most Important Meal of the Day or a Myth That Refuses to Die? Science Has a Surprising Answer

For decades we were told that breakfast is the king of all meals. Then intermittent fasting arrived, and suddenly the morning meal became optional, even "counterproductive" for anyone trying to lose weight. Headlines swing from one extreme to the other. So who is right? The honest answer, according to the latest research, is that both camps are partly right, and the details matter far more than the slogan.

Hugh Jackman is one of the best-known examples of the "skip it" camp. To get into shape for his role as Wolverine, the actor followed the 16:8 eating pattern, reported by Men's Health, in which all food is eaten within an eight-hour window and nothing (apart from water, unsweetened tea or black coffee) is consumed for the remaining sixteen hours. In practice, that usually means no traditional breakfast. It is worth keeping in mind, though, that Jackman was training intensively several hours a day with professional guidance, which is a very different situation from an ordinary office morning.

Our readers tell us about the opposite experience just as often. One reader wrote to us that she spent years drinking only coffee until lunchtime, convinced she was "saving calories", only to find herself raiding the office biscuit tin by late morning and snacking all evening. When she switched to a small breakfast with eggs and a slice of wholegrain bread, the afternoon cravings settled down within a couple of weeks. Two people, two opposite strategies, and both felt they had found what works. That is exactly why the question deserves a closer look.

Why the Morning Matters for Fat Burning

When we wake up, the body has spent the night (mostly) without food. During this time the digestive organs have had a chance to rest and process the leftovers of the previous evening's dinner. Levels of the hormone insulin (the hormone that helps glucose, or sugar, move from the blood into the cells) are typically low at this point. This gives the body an opportunity to draw on its stored energy, including fat, instead of immediately using sugar from food.

If, however, you immediately flood your bloodstream with sugar from a slice of white bread, a sweet pastry, a banana or a glass of juice, insulin rises quickly, and the body switches to using this "fresh" energy rather than its fat reserves. So if you would like your body to tap into its own reserves, the morning offers a natural window to do so.

Does This Mean You Should Skip Breakfast?

Not necessarily. It all depends on what you want to achieve. If you are not planning an intense workout first thing in the morning, it may make sense to start the day at a gentler pace (water, unsweetened tea or coffee without sugar), so that you do not trigger a large insulin response straight away.

But be careful: research suggests that regularly skipping breakfast is not without its downsides.

A large Korean study based on the Korea National Health and Nutrition Examination Survey (2016–2018), published in the International Journal of Environmental Research and Public Health, found that people who never ate breakfast had 1.42 times higher odds (about 42% higher) of elevated insulin resistance than those who ate breakfast five to seven days a week. Even eating breakfast only one to four times a week was associated with somewhat higher odds. It is important to note that this was an observational study, so it shows a link, not proof of cause and effect.

A 2023 systematic review and meta-analysis in Frontiers in Nutrition, which pooled 40 studies with more than 320,000 children and teenagers, found that young people who skipped breakfast were about 59% more likely to be overweight or obese than those who ate breakfast regularly.

On the other hand, adults tell a slightly different story. A meta-analysis of 13 randomised controlled trials published in The BMJ by researchers from Monash University found that people who skipped breakfast weighed on average about 0.44 kg less than those who ate it. The explanation is fairly simple: breakfast eaters consumed around 260 more calories per day, meaning that people who skipped the morning meal spontaneously ate less over the course of the day.

At the same time, the authors themselves warned that most of the included trials were short and of low quality, so the long-term benefits of skipping breakfast have not been demonstrated.

In other words, skipping breakfast may help reduce calories in the short term, but in the long run it is linked with possible risks, especially for blood sugar regulation and for children.

Is Breakfast Still the "Big Meal of the Day"?

There is also a strong opposing view: that it is better to distribute calories so that more energy comes in the morning and less in the evening. The old saying "eat breakfast like a king, lunch like a prince and dinner like a pauper" has some scientific support.

In a well-known study often called the "big breakfast" trial, researchers led by Professor Daniela Jakubowicz at Tel Aviv University divided 93 women with overweight into two groups eating the same 1,400 calories per day. One group had a 700-calorie breakfast and a 200-calorie dinner; the other did the reverse. According to the results published in the journal Obesity, the big-breakfast group lost more weight and more waist circumference, and showed greater improvements in fasting glucose, insulin and insulin sensitivity, while triglycerides actually rose in the big-dinner group.

Not every study agrees, however. A later, carefully controlled trial from the University of Aberdeen, published in Cell Metabolism in 2022, found no difference in weight loss between a big breakfast and a big dinner, but participants who ate more in the morning reported feeling noticeably less hungry during the day. For many people, that alone can make healthy eating much easier to stick with.

The composition of breakfast appears to matter as much as its size. A study from the University of Missouri, published in The Journal of Nutrition, found that in people with type 2 diabetes, a protein-rich breakfast led to a lower rise in blood sugar after the meal (about 17% lower) than a carbohydrate-heavy breakfast, without increasing the response to lunch.

In another trial involving people with type 2 diabetes, published in the Journal of Nutritional Biochemistry, a higher-protein breakfast reduced the overall rise in blood sugar across the whole day by 12% to 19% compared with a high-carbohydrate breakfast, depending on the protein source, even though lunch and dinner were the same.

So: if you do eat breakfast, it is worth putting it together thoughtfully, with protein, fewer "fast" sugars and without making it too heavy.

What You Can Do at Home

Here are a few habits rooted in traditional practices and supported, at least in part, by modern research:

• A drink before you eat
  
  Start the morning with a glass of lukewarm water, with a squeeze of lemon if you like. If you really cannot do without sweetness, a small teaspoon of honey is a gentler option than a sugary drink. This is a pleasant way to wake up the digestive system without causing a large spike in blood sugar.



• Breakfast with protein and wholegrains
  
  Instead of sugary cereals, pastries or fruit juice, try a simple combination: a couple of eggs (fried, scrambled or hard-boiled), a portion of wholegrains (wholegrain bread or buckwheat porridge) and a piece of fruit with a low glycaemic index. The glycaemic index describes how quickly sugar from a food appears in the blood; the lower it is, the more gradual the rise. Good examples are apples, pears and plums. Protein not only helps keep blood sugar steadier, it also keeps you feeling full for longer. If your mornings are rushed, our The 2-Minute Breakfast Swap Nutritionists Keep Coming Back To: Chia, Coconut & Blueberry Blend is a quick alternative that requires no cooking at all.



• Shift more food to the morning
  
  If you usually eat a lot in the evening, try the reverse: make breakfast or lunch your main meal and keep dinner light and smaller. This fits with the idea of eating more when you are most active, and with the observation that the body tends to handle food better earlier in the day. Late, heavy meals can also affect sleep, and sleep in turn affects appetite, as explained in When you sleep too little, your belly grows. For more on which foods are best avoided at either end of the day, see What not to eat early in the morning (or late at night).



• Pay attention to the gaps between meals
  
  If you prefer to start the day slowly, you can simply move breakfast a little later and set a time window for eating (for example, from 10 a.m. to 6 p.m.). But be careful: skipping or delaying meals should never come at the expense of the overall quality of your diet. Hunger that is postponed has a habit of returning at the worst possible moment, as described in The Three Moments Each Day When Your Willpower Is Weakest — and Your Cravings Are Strongest.



• Move after breakfast
  
  After eating, take a light 10 to 15-minute walk. Movement helps the muscles use sugar from the blood. This is an old folk habit, and research supports it: a 2022 analysis published in Sports Medicine by researchers at the University of Limerick found that even a few minutes of light walking after a meal was associated with a smaller rise in blood sugar than sitting.

When Breakfast Matters Most (and When It Matters Less)

If you plan to exercise intensively in the morning (running, gym training), you will probably benefit from a small amount of protein and carbohydrates beforehand, so you have enough energy and do not cut your workout short. A simple, warming option can be found in Breakfast for more energy before a physically demanding day.

If your goal is to reduce body fat, you can wait a while before a proper meal and start the day with a drink, then eat a well-planned breakfast a little later in the morning.

If you have diabetes or another metabolic condition, take medication that affects blood sugar, are pregnant or breastfeeding, or have a history of disordered eating, talk to your doctor or a registered dietitian before changing your meal pattern, as skipping breakfast is not suitable for everyone.

Irregular mornings can also catch up with you in less obvious ways. Many people notice that a later, rushed weekend breakfast comes with a headache or a dip in mood, a pattern described in The Weekend Headache Nobody Warns You About.

What the Experts Say: There Is No One-Size-Fits-All Recipe

The media love drama, so you will read either "breakfast is the most important meal of the day!" or "skip breakfast and lose weight!" But research shows that the effects are modest and differ from person to person. As registered dietitian Antigone Senn explains in an article for Henry Ford Health, what matters most for metabolism is the total amount of food you eat over the day, not simply the time at which you eat it. At the same time, experts at Stanford Lifestyle Medicine point out that regular meal times and an earlier eating window may work better with the body's internal clock than very late eating.

With breakfast, as with most things, the key is balance. Be wary of absolute rules such as "breakfast always" or "breakfast never". A better principle is: "breakfast should be adapted to your day, your goals and how your body responds to sugar."

A practical approach is to start the morning with something light (water or tea), wait a little, and when you feel ready, continue with a more substantial breakfast built around protein, wholegrains and a piece of fruit. If you notice that you crave sweets or feel a drop in energy after breakfast, try reducing the amount of sugar the next day and see how you feel.

With this approach, you can make the most of the morning without putting your body under unnecessary strain.