It is often said that breakfast is an essential part of a healthy diet, especially when it comes to taking care of your figure.
But not everyone finds it easy to eat so early in the morning: in Europe and the United States, between 10% and 30% of the population skips breakfast.
adolescent girls are the most likely to do so, claiming that they do not have time or hunger or that they are on a diet.
Skipping breakfast goes against what is generally advised: the logic is that those who do not eat early will be hungry for the rest of the day and therefore tempted to eat high-calorie snacks, which leads to weight gain.
The theory is reasonable, until you try to find evidence that people who do not eat breakfast consume more calories than those who do.
Bulk studies
Not so easy
The impact of not eating breakfast on weight is more difficult to study systematically than one would expect.
The first problem is how to define that first meal of the day: how much has to be eaten to count as breakfast? how early does it have to be eaten to be considered 'breakfast'?
For example, when the U.S. Department of Agriculture conducted a systematic review of research on the subject, it found that most studies defined 'breakfast' as food eaten before 10:00 a.m. Anyone who ate at 10:05 a.m. was considered to have not eaten breakfast (3).
Another difficulty is that what is eaten for breakfast varies from country to country. In Scandinavia that morning meal may include smoked fish, in Germany, deli meats, in the UK, boxed cereals. This makes the study of the impact of breakfast more difficult on a global scale, as the nutritional benefits depend on what is eaten.
However, if we limit ourselves to reviewing the calories consumed, there have been several attempts to elucidate the influence of breakfast on a person's weight.
A review of studies conducted before 2004 (4) found that breakfast skippers do not tend to consume more calories during the rest of the day to compensate.
What was revealed about weight is a bit more complex. Four studies found that children who did not eat breakfast had on average a higher body mass index, but three other studies showed that it made no difference.
The advantage of the first four studies is that the teams had more rigorously controlled for factors that might have biased the results. So the evidence is starting to lean slightly toward a link between missing breakfast and weight gain.
To muddy the waters, a 2011 U.S. review (5) cited five studies on such a link: three said it did not exist and one found the opposite, i.e., that among overweight children, those who ate breakfast were fatter.
And, to confound matters further, a meta-analysis (6) that collected the results of 19 studies done in Asian and Pacific regions found an association between skipping breakfast and weight gain. A European systematic review (7) obtained similar results, although one of the studies showed that only boys who ate breakfast gained weight.
Upside down
What if one flips the question? Instead of saying, "seven studies found that children who skip breakfast tend to be fatter," one could say that seven studies found that overweight children were more likely to skip breakfast.
That's the problem with these studies: they take a snapshot, they don't explore causes.
We don't know which came first, the overweight or the habit of not eating breakfast.
Perhaps those children had stopped eating breakfast because they were fat and were trying to eat less.
The alternative is to study people over a long period of time, and the first longitudinal study on this topic was done in 2003 (8). When the researchers started they found that children who skipped breakfast weighed more on average. But when they followed those same children for three years, it was the fat children who skipped breakfast who lost weight over time.
So we are left with a situation where there are many studies - but definitely not all - that show that kids who skip breakfast are more likely to be overweight. However, we can't be sure if the reason is their diet or the fact that they don't eat breakfast. And if the latter is the cause, it is not clear why, since they do not consume more calories in total (9).
Change of routine
If it is not the total calories consumed, does the timing of the meal make a difference? Are three smaller meals better than two larger ones?
Very few randomized controlled trials have been done on this subject, but there is one that was carried out in 1992 in adults (10). A group of obese women were given diet plans in which they all ate the same amount of calories per day, but not always at the same time: half had three meals a day while the other half had no breakfast, but had lunch and a larger dinner.
The results are fascinating.
Those who were used to skipping breakfast lost more weight if they were put in the breakfast group, while those who before the experiment ate in the morning lost more weight if they stopped eating breakfast. In other words, a change in routine helped them lose weight.
So perhaps the lesson from that study is that you simply have to do something different. At the University of Hertfordshire in the United Kingdom, a team of psychologists has developed a weight-loss program based on that premise.
So?
The picture is confusing, which is why a new study (11) on dieting myths was recently published, which includes skipping breakfast as one of the unproven assumptions.
However, breakfast may have other benefits. A randomized controlled trial conducted in rural Jamaica and Peru (12) showed that children who ate breakfast at school had better grades. The results cannot be generalized as the children studied may have been suffering from malnutrition prior to the study, so a breakfast may not make as much difference to well-nourished children.
So the million dollar question is: should you eat breakfast or not, if you want to lose weight?
The diet of breakfast eaters tends to be more balanced in general, but if it is just for weight loss, until further studies are conducted, it depends on personal preference.
Some of us just can't pass an early snack. If that's you, you can blame your biological clock: recent research found that night owls simply don't get hungry in the morning (12). In that case, until a really good randomized controlled study proves otherwise, perhaps it's best to listen to your stomach, not go against it.
