Jury's out on link between breakfast and body weight
EATING breakfast is a simple habit that helps prevent weight gain, we have long been told.
Skipping breakfast, the thinking goes, increases hunger throughout the day, making people overeat and seek out snacks to compensate for missing that first - and some would say most important - meal of the day.
But new research shows that despite the conventional weight-loss wisdom, the idea that eating breakfast helps you lose weight stems largely from misconceived studies.
Only a handful of rigorous, carefully controlled trials have tested the claim, the new report, published in The American Journal Of Clinical Nutrition, found.
And, generally, they conclude that missing breakfast has either little or no effect on weight gain, or that people who eat breakfast end up consuming more daily calories than those who skip it.
But those trials have been largely overlooked, and their findings drowned out by dozens of large observational studies that have found associations between breakfast habits and obesity but no direct cause and effect, said Dr David Allison, director of the Nutrition Obesity Research Center at the University of Alabama at Birmingham.
Dr Allison and his colleagues scoured the medical literature and found that the only long-term, carefully controlled trial that randomly assigned people to routinely eat or go without breakfast and then measured the effect on their body weight was published in 1992.
That seminal study, carried out over 12 weeks at Vanderbilt University, had mixed results.
Moderately obese adults who were habitual breakfast skippers lost an average of roughly 8kg when they were put on a programme that included eating breakfast every day.
And regular breakfast eaters who were instructed to avoid eating breakfast daily lost an average of nearly 9kg.
Both programmes included an identical amount of calories, and each caused people to lose more weight than a programme in which a person's typical breakfast habits did not change.
The study suggested that as far as breakfast is concerned, the most important factor in weight loss may be how drastically you change your routine.
"Those who had to make the most substantial changes in eating habits to comply with the programme achieved better results," the authors wrote in their paper.
Dr Allison said that the true relationship between eating breakfast and body weight, if there is one, was still an open question.