This notion is deeply engraved in the mindset of most people. However, science has a thing or two to say about this matter.
Some observational evidence
In the past, whole grain breakfast cereals have been associated with a lower risk of heart disease, mortality, diabetes, higher blood pressure, and weight gain in men, as well as a lower BMI and risk of obesity in the general population. Others have also found that people who regularly consume breakfast also eat healthier throughout the day – however, these findings were not true for all types of breakfast. Furthermore, according to some observational studies, children and adolescents who eat breakfast regularly, tend to be slimmer and are less likely to be overweight.
In certain studies, it was noted that people tended to be slimmer when they were eating cereals for breakfast, but not when they were eating other types of breakfast, say eggs and ham. Now, this raises a few questions – does breakfast magically make the tummy go away? Do cereals hold magic superpowers? Well, no. Not really. The studies which have demonstrated cereal breakfast superiority were sponsored by cereal companies. Who would have guessed right!
And while I cannot offer an answer whether cereals hold magic superpowers, I can offer an answer whether breakfast makes the tummy go away by magic.
But, that is observational evidence
Exactly, all the mentioned studies were observational. In these studies, researchers are interested in a connection between two different variables. In this case it was BMI and breakfast consumption. However, such studies usually give us the weakest evidence. They never show exact causality, only correlation.
Therefore, it is really hard to pinpoint exact answers. I mentioned the lower BMI in those who eat breakfast. Well, at the same time they found that these people spend more energy than they take in. Shocking news? Is this why they were slimmer and not the pixie dust in cereals? Other results show that people, who were under reporting how much they ate, were excluded from the analysis. When they weren’t – there were no differences between the two groups.
This opens the Pandora’s box of questions.
What if overweight people who reported not eating breakfast, are simply doing that because they were trying to lose weight through skipping it? What if there is a general tendency for overweight people who don’t eat breakfast, to under report how much they actually eat? What if breakfast eaters are also more active throughout the day – and vice versa for the others?
These questions are the reason observational evidence is weak, none of them can be answered simply on the basis of the mentioned studies. This serves as yet another reminder why observational evidence is a very weak judge in science.
But I will feel more full and eat less throughout the day, won’t I?
No, not really. At least according to a recent clinical trial which found out that people who did not eat breakfast, despite being hungrier for lunch and eating more, ate less throughout the day.
However, there is a warning we must mention – Insulin sensitivity. It’s associated with increased feelings of satiety, reduced hunger, and lower energy intakes – so with improved insulin sensitivity you would feel less hungry, probably eat less, and feel full longer after a meal.
And why am I mentioning this?
It is possible that regular breakfast consumption could improve insulin sensitivity and increase the amount of energy you spend during the day due to eating itself (thermic effects). One study was testing exactly this idea and found no evidence of this effect. So much for that.
On the other hand.
Others have investigated and found that eating breakfast lead to eating less throughout the day, and not eating breakfast for two weeks did impair insulin sensitivity. However, these findings were observed on 10 women. And grand theories about humanity can hardly be derived from such small studies. Further research in this field will be appreciated and needed.
Let’s wrap it up
- Different types of regular breakfasts have been associated with a lower risk of heart, total mortality, diabetes, higher blood pressure, and weight gain in men, as well as lower risk of obesity and a lower BMI.
- Children and adolescents that are habitual cereal breakfast eaters tend to be slimmer and less likely to be overweight than those who do it infrequently or not at all.
- These effects have been observed only in observational studies – nothing causal can be concluded from that directly.
- Increased insulin sensitivity is one of the possible mechanisms that exert the observed effects.
So does eating breakfast have any special powers? Not really. If you re hungry in the morning, eat. If you’re not, don’t. Simple.