“Educating is not teaching facts, it is teaching to think” – Albert Einstein
As is often the case, a new study has fueled the breakfast debate. It is a Spanish study, with the following conclusion: «Skipping breakfast is associated with an increased risk of atherosclerosis«.
From this conclusion the campaign of disinformation:
Today we look at the hidden behind these studies, probable explanations, the bad science of breakfast, and the dangers of eating too late.
The fraudulent science of breakfast
Official nutrition recommendations are based on shifting science. Relying mainly on observational studies is one of its main weaknesses.
Correlation or Causality?
Observational studies can find correlation, but not show causality. A clear example: ice cream consumption is associated with drowning deaths.
It can be just random. If the analyzed data set is large enough you will find random relationships. For example, the number of Nicolas Cage films shows a strong correlation with the number of people drowned in swimming pools.
In many cases the association found is not random, but is caused by a third variable that explains both. The association in the previous example, between consumption of ice cream and drowning, is explained in this case by the increase in temperature. The sun causes people to eat more ice cream and also bathe more, increasing drownings.
Returning to the case of breakfast, is there a possible cause that explains the two related variables (atherosclerosis and skipping breakfast)? Yes, the bad habits.
As the study itself details, the group of participants who skipped breakfast included more smokers and heavy alcohol users (Article). Everything points to a new case of confusion between causality and correlation. Are they less sick or obese because they eat breakfast or because they don’t smoke or drink and exercise more? Probably the latter.
The next question would be why people with bad habits tend to skip breakfast, and the main answer is the well-known healthy user bias.
The healthy user bias
Habits usually come in groups. Those who are concerned about their health adhere to most general recommendations. Those who ignore their health also ignore the recommendations to improve itThey smoke more, drink more alcohol, eat worse, and exercise less.
If breakfast is a general recommendation, the usual will happen: Those who take care of their health eat breakfast, and the rest only do it if they feel like it.
Any subsequent observational study will draw the same conclusion: ‘Eating breakfast is associated with better health«. But having breakfast is not the cause of better health, and if there is causality it would be the reverse: «Those who monitor their health usually eat breakfast«.
Shouldn’t researchers be more rigorous in disclosing their findings? Yes, but there is a problem. Rather than researchers, they are humans, influenced by same cognitive biases as the rest of us (detail).
Other cognitive biases
The researchers also grew up with Kellogg’s and with the firm belief that having breakfast like royalty is the best. When conducting studies, they look for evidence to support this belief. But this review details how the strength of the belief far exceeds the strength of the evidence.
As the review describes, this conviction leads to two main problems:
- Investigation without probative value. Most studies on breakfast are observational, with the limitations we saw earlier.
- Research biased reporting. When reporting the conclusions, the researchers use language that assumes causality, despite only finding an association. This also attracts the attention of the media, increasing the likelihood of receiving new funding. Certainty, however wrong, generates more headlines than uncertainty.
Not only that. In addition to assuming causality, they invent possible explanations. For example, one of the study authors comments as follows: “You eat later and eat more calories than you should”. Is this true? No actually most clinical trials conclude otherwise.
This study for example indicates that skipping breakfast can be beneficial for weight loss by reducing total caloric intake. The same indicates this other study in adolescent women, this in men and this in children. The idea that skipping breakfast provokes super offsets huge posteriors is unfounded.
And I repeat, these are controlled clinical trials, which can prove causation. Skipping breakfast doesn’t make you eat more.
Finally, a recent meta-analysis concludes the following: «Incorporating breakfast may not be a good weight loss strategy, regardless of established habits. Caution is required when recommending breakfast to lose weight, as it could have the opposite effect«.
And in fact, we have evidence of the effect of confusing causality with correlation. In the first large study that offered breakfast to children in schools, obesity tripled. And something similar in the case of adults, where skipping breakfast leads to weight loss (meta-analysis, meta-analysis).
As a previous review indicates, another problem in breakfast research is that scientists rule out explanations that don’t fit their hypothesis. Let’s explore a couple of examples.
In some cases, skipping breakfast could lead to unhealthy behaviors:
- People who don’t eat breakfast at home but attack the vending machine in the middle of the morning. As we saw before, they will not necessarily eat more throughout the day, but they will probably eat worse. If you are used to intermittent fasting and eat well the rest of the day, skipping breakfast will not have a detrimental impact.
- Those who are not hungry in the morning may have emptied the refrigerator at dawn. We are diurnal beings, and we’re scheduled to eat more calories during the day. This aspect may be relevant. Let’s go deeper.
Eat at night
As I explained in this article, meal times matter, and multiple studies in mice confirm that when they eat outside their biological activity schedule, they gain more weight, even with the same caloric intake.
Mice are nocturnal animals, but humans are diurnal. Concentrating more calories during the day produces better results than bingeing at night, but this is independent of whether you have breakfast first thing in the morning or simply have a larger daytime meal with a small dinner (study, study).
This recent clinical trial compared the response to two meal patterns, one between 8am and 7pm and another between 12pm and 11pm. Bringing meals into the evening was found to impair metabolic flexibility, increasing glucose burning and reducing fat burning. There was also an increase in glucose, insulin and triglycerides (study). The same in this other studies like this, this, this, this or this.
A recent study also observed a greater elevation of inflammatory markers in those who dined late.
Why is this happening? We know at least four mechanisms:
- The melatonin it rises at night to signal to the body that it is time to sleep, reducing the function of certain organs, interfering for example with glucose control (study, study, study, study). People with a specific variant of the MTNRIB gene are especially sensitive (study).
- Digesting food raises body temperature, delaying the onset of sleep. Thermal reduction is another sign that helps us rest (study, study, study).
- Food thermogenesis is much higher during the day (study, study), making nighttime calories something more fattening.
- Dining too late reduces fatty acid mobilization and oxidation (study).
Like any general recommendation, it requires qualification. We know, for example, that the body has a great capacity for adaptation, and that the peripheral clocks of the organs can be synchronized with different schedules, but evolutionarily it is less efficient.
A recent meta-analysis also shows worse results at night, although it is inconclusive. And when reviewing studies that talk about dinner, we must not forget that in Anglo-Saxon countries dinner is served much earlier than in Spain. Dining at 6-8pm is different than at 10-11pm.
And one more piece of information, physical activity mitigates the negative effect of nighttime calories (study). If you eat dinner late but train earlier, the risk is lower.
Finally, we cannot ignore the perverse industry influence on breakfast recommendation.
Many studies on breakfast are funded by the industry that sells its products to us. No matter how objective researchers try to be, we know that the origin of the funds conditions the conclusions (detail). Who puts the money puts the music, it is the well-known financing bias. These companies also pay for public campaigns on healthy habits (including breakfast), leading to nonsense such as the HAVISA Plan.
The Ministry of Health does not partner with fruit and vegetable producers (they don’t pay enough), but with the big junk food multinationals:
- Coca-Cola and Pepsi: The sugar mafia bosses giving lessons on healthy habits.
- Kellogg’sJohn Harvey Kellogg was a strange character obsessed with spiritual purity, enemas, and celibacy (more detail), and his creation made breakfast the worst meal of the day.
- Panrico Donuts: Nobody would put donuts in the food, but it seems that they are acceptable for breakfast.
- Bimbo: Because a breakfast without sliced bread toast cannot be healthy. And don’t miss what Bimbo tells us will happen if you put down the bread.
- Idyll: The makers of ColaCao and Nocilla. Little more to add.
- Mondelez: Manufacturers of nutritious breakfast items like Oreo, Chips Ahoy, or Ritz cookies. As much as they tell you, cookies are pastries, especially these brands.
- Nestle. Not all their products are rubbish, but their breakfast options are crazy (Chocapics, Cheerios, Nesquik…).
Remember these dangerous relationships when the Ministry of Health tells you about the importance of breakfast.
If I could replace the hackneyed idea of ’Breakfast is the most important meal of the day»For more scientific and accurate recommendations, it would be something like this:
- Maximize calories during the day and reduce calories at night, leaving at least a couple of hours before going to bed.
- Concentrate meals in a shorter time slot, with some intermittent fasting strategy that does not force you to eat large meals at night. More detail.
- Brings higher calorie intake closer to physical activity. Calories after training have an effect special. If you train early in the morning, having breakfast afterward can be interesting.
As a final idea, having breakfast has nothing magical, but nothing bad either. If you enjoy it and wake up hungry, go ahead. Of course, forget about the official prescription. Have real food for breakfast.