Starting the day off with a hearty breakfast has proven to have a multitude of health benefits, says Rod Tucker
Breakfast is the first meal of the day and arguably important for health reasons. Evidence from epidemiological studies suggest a link between skipping breakfast and an increased risk of coronary heart disease (CHD). Other work in children and adolescents also concluded that missing breakfast is associated with a greater risk of metabolic syndrome.
These possible health risks have prompted organisations such as the Association of UK dietitians and the breakfast is best campaign to stress the importance of having a regular breakfast as part of a healthy lifestyle. The reason that skipping breakfast is perceived as a potentially unhealthy practice is based on the notion that eating later in the day leads to greater snacking and ultimately weight gain, which increases the risk of CHD.
A recent prospective study published in the April issue of the Journal of the American College of Cardiology provided further support to the view that skipping breakfast is bad for our health. The authors followed 6,550 people with an average age of 53 (40 to 75 years of age) for 18 years. People were categorised as ‘never’, ‘rarely’, ‘some days’ and ‘every day’ breakfast eaters.
The results showed that, compared to those who ate breakfast every day, there was an 87% increased risk of cardiovascular-related deaths for those who never ate breakfast and an overall 19% increased risk of death. Moreover, these findings are consistent with others as summarised in systematic review of prospective studies.
Prospective studies are a useful way of identifying links between various factors (ie breakfast skipping and CHD) but such studies cannot prove causality. In other words, while two factors might be associated, this is no proof that one causes the other.
So, should we be alarmed by these findings and all start having breakfast?
Emerging research is beginning to shed some light on a possible explanation for the findings of these prospective studies. The underlying and connecting theme is the body’s biological clock and circadian rhythms. All of us have a master clock in our brains but also clocks in the heart, liver, intestines and various other organ systems which are synchronised by the master clock.
Humans are a diurnal species. We are designed to feed when it is light and sleep and fast when it is dark. Any perturbations of this rhythm affects metabolic functioning, energy balance and ultimately weight. This was illustrated in a study of patients attempting to lose weight that found that greater weight loss occurred in those who were early eaters (eating before 3pm) compared to those who ate after 3pm.
What was particularly interesting was that energy intake, energy expenditure and the composition of the diet were similar in the two groups. Other work in patients who had bariatric surgery has also found that eating earlier in the day was more effective for weight loss.
The important role of the circadian rhythm misalignment has been demonstrated in those doing shift work, who are at an increased risk of obesity, diabetes and cardiovascular disease. Furthermore, simply eating later in the day is linked with increased body fat and evidence of the harm of inappropriate meal timing was seen in a study of both healthy and diabetic patients. In this study, eating later in the day negatively affected gene expression leading to higher plasma glucose levels after only one day of breakfast skipping.
So, should pharmacists advise patients to always eat breakfast? Possibly. It seems that what is more important is that the bulk of calories are consumed earlier in the day, thus aligning with our circadian rhythm. During the 1960s, health food guru Adelle Davis coined the phrase ‘Eat breakfast like a king, lunch like a prince and dinner like a pauper’. Although at the time little was known about circadian rhythms, her advice is now beginning to sound eminently sensible.