Breakfast is a Dangerous Meal: Why You Should Ditch Your Morning Meal For Health and Wellbeing

And to confirm that model of association, not causation, there has even been a report that Japanese girls who skip breakfast also start to have sex two years before their breakfast-eating sisters (at 17.5 rather than 19.4 years of age). The report has not got into an English-language peer-reviewed journal, but it came from the Japan Family Planning Association, which is credible.

Here is a model that captures that story:

The model is not:

dysfunctional teenagers → skip breakfast → have premature sex

Daniel, the lions’ den and the earliest clinical trial

Epidemiology (from the Greek epidamia, the prevalence of disease) is the science of populations, but it’s too easy in epidemiology to confuse cause and correlation. So here is a claim of cause:

eat breakfast → eat more → yet lose weight, paradoxically

(or alternatively)

skip breakfast → eat less → yet gain weight, paradoxically

and here is a claim of correlation:

Epidemiological studies that look only at breakfast and weight can easily confuse correlation with cause – except that the science of epidemiology has long generated a ‘hierarchy of evidence’ by which to distinguish them, and it is a theme of this book that epidemiologists have not always been sufficiently rigorous in applying that hierarchy.

The hierarchy of evidence: Conflicts over diet are age-old, and some can be sourced to the Bible. Daniel was a Jew who had been captured by Nebuchadnezzar, the King of Babylon, and who was consequently condemned to various vicissitudes including the lions’ den (from which, happily, he was rescued). Daniel was also instructed to eat the food of the royal court, to which he objected on grounds of observance. Let Daniel I: 12–16 take up the story of how he asked that he and his fellow captives be given:

nothing but vegetables to eat and water to drink. Then [Daniel said] compare our appearance with that of the young men who eat the royal food, and treat your servants in accordance with what you see. So he [the chief official] agreed to this and tested them for ten days. At the end of the ten days they looked healthier and better nourished than any of the young men who ate the royal food. So the guard took away their choice food and the wine they were to drink and gave them vegetables instead [New International Version].

This was a clinical trial! The first to have been recorded. But though it wasn’t too badly controlled, we think we can do better now, and today we understand that some methodologies are more powerful than others and that they can be ranked in a hierarchy of evidence:

Systematic reviews and meta-analyses

Randomised blinded controlled trials

Randomised controlled trials

Cohort studies

Case-control studies

Cross-sectional surveys

Case reports.

Let me briefly look at these, starting with the weakest methodologies.

7. Case reports: In such a report, the medical history of a patient is told as a story. ‘Mr Joe Blogs has always smoked and he has just celebrated his eightieth birthday, therefore smoking potentiates longevity.’ It doesn’t require genius to understand why case reports provide only weak evidence of cause and effect.

6. Cross-sectional surveys: These are ‘snapshots’. In such studies, people are asked two questions, which might be: what do you eat for breakfast and what is your weight? As I’ve shown above, many breakfast studies fall into this category, which is unfortunate because this sort of snapshot study can be very misleading, i.e. at any one time people may be large and thus skip breakfast while, later, those people may be slim and thus eat it, but it is not the eating of breakfast that makes you slim (and, vice versa, not the skipping of breakfast that makes you fat); rather, it’s being large that encourages people to skip breakfast, and being slim that encourages people to eat it. So cross-sectional or snapshot studies can lead to conclusions that are 100 per cent wrong.

5. Case-control studies: These are not used frequently in breakfast research, so I’ll not describe them here.

4. Cohort studies: These are an attempt at avoiding the problems of a ‘snapshot’. In a cohort study, two groups of people are selected because they either do or do not eat breakfast (say) and then some years later their outcomes are determined. During the 1940s, 1950s and 1960s Bradford Hill and Richard Doll performed their famous cohort study on doctors who either did or did not smoke, discovering that smoking causes lung cancer.

3. Randomised controlled trials: Now we are moving from observations to experiments, where participants are given a drug or some other intervention (such as skipping breakfast or not eating the royal food) and scientists then determine the effect.

Experiments, though, are only as good as their controls: if you give a drug to a group of people and then get an effect, you need to know that those people were not going to produce that effect anyway, so in clinical medicine we do controlled trials, where the responses of subjects to a drug are compared to the responses of subjects who do not receive the drug. But the experimenter mustn’t pick the control subjects, because that might bias the results, so in clinical medicine we do randomised controlled trials, where the two groups of subjects are selected to be as similar as possible, with individuals being distributed between the two groups randomly.

2. Randomised blinded controlled trials: Ideally, to avoid subconscious bias, neither the experimenters nor the subjects of a trial should know who is part of the intervention group and who is part of the control group, but unfortunately I need not explain this any further as we can’t do blinded trials in breakfast: blinding requires that we provide control subjects with placebos, yet we can’t provide placebos for breakfast. Breakfast studies have therefore been deprived of the most robust experimental protocols, but as the science of astronomy illustrates, knowledge can progress without the full panoply of experimental protocols: if we are careful in our observations, we can – in the absence of experiments – show that the earth moves round the sun rather than vice versa, but we do have to view the observations carefully, without preconceptions.

1. Systematic reviews and meta-analyses: These are sophisticated words that describe the sophisticated methods by which the results of many different trials can be pooled, to provide more secure conclusions than any one trial can provide.

Conclusion: Clinical medicine has created a hierarchy of evidence, and in this book I try to show where breakfast epidemiologists have, unfortunately, ignored the hierarchy, to thus confuse correlation with cause.

9 (#ulink_2ce599be-ef7b-5daf-94a6-42cdfc60a8b1)

Five breakfast sagas (#ulink_2ce599be-ef7b-5daf-94a6-42cdfc60a8b1)

I have explored the two major explanations for the apparent paradox of breakfast eaters consuming more calories than breakfast skippers while being slimmer; now let me offer five more:

1 Healthily minded people ‘know’ they should eat breakfast

2 People under-report their food intake

3 Breakfast skipping is not properly defined

4 ‘Kick-starting’ metabolism

5 Breakfast skippers are owls, not larks.

Let’s look at these in turn.

1. Healthily minded people ‘know’ they should eat breakfast (aka the ‘compliance’ effect): Consider a survey published in 2003 from the Massachusetts Medical School.

That survey confirmed that people who ate breakfast were slim, but the researchers warned that their ‘findings cannot be considered causal’ because most of their subjects were ‘white middle class members of a health maintenance organization … [who] were highly motivated … in their own health’. And what in 2003 did members of health maintenance organisations know? They knew that breakfast was the most important meal of the day! Most of the survey’s subjects were, therefore, complying with medical advice to eat breakfast, but they were also complying with the advice of not overeating during the course of the day.

Normally, of course, people do well to comply with medical advice, but such compliance can sometimes be dangerous. Consider vitamin D deficiency. A Swedish medical team has monitored a cohort of some 30,000 healthy women, of whom some 2,500 died from natural causes over twenty years. To minimise their risks of developing malignant melanoma, many of the women had avoided exposure to the sun. Such women had thus become vitamin D deficient and, as a consequence, their overall death rate from all disease … doubled. In the words of the paper: ‘the mortality rate amongst avoiders of sun exposure was approximately twofold higher compared with the highest sun exposure group … the effect was presumably attributable to cancer, heart disease and cerebrovascular disease.’

Compliance dangers are perennial because medical science advances perennially, and such advances invariably take doctors and patients into unknown territory, where the law of unintended consequences can apply. And one important compliance danger is breakfast. Your doctor may assure you that breakfast is the most important meal of the day, but that self-same doctor would once have assured you that babies have to be laid to sleep on their tummies (see below).

Cot deaths and neonatal blindness: compliance dangers

When our first child was born, in 1991, the world was still in the grip of the epidemic of cot deaths that had, unexpectedly, erupted some years earlier. To minimise the risks to our child, my wife and I were told to lay her to sleep on her tummy. But when our second child was born, in 1993, we were told to lay him on his back. It transpired that more than half of cot deaths before 1992 had occurred because babies had been laid to sleep on their tummies; and they were sleeping on their tummies because studies had shown that sick babies in intensive care units did better on their tummies. Fair enough. But that observation was then extrapolated, without proper testing, to healthy babies at home; and those do worse on their tummies, so their death rates rose.

Perhaps the best-known example of compliance danger is provided by Stevie Wonder, whose blindness was caused by his having been given, as a sick baby, 100 per cent oxygen to breathe. Routinely giving 100 per cent oxygen to sick babies – regardless of their illness and regardless of their actual need for extra oxygen – was once conventional until doctors realised that the contemporary epidemic of infant blindness was being caused by the excessive oxygen that, by stimulating the uncontrolled growth of certain cells in the eyes, was destroying the babies’ vision.

We can go on multiplying the recent examples of doctors being wrong (I’m not talking leeches here, I’m talking about modern doctors). Consider hormone replacement therapy (HRT) for the menopause. For half a century this was lauded by doctors, and for years ‘it was considered malpractice if you did not prescribe HRT for menopausal women.’

Only with the publication of the two Women’s Health Initiatives in 1992 did the breast cancer story emerge, and HRT is now prescribed with circumspection.

These stories are relevant to breakfast because they confirm that modern doctors can sometimes be wrong in their advice, advice over breakfast not excluded.