Well, it turns out that when Dr Farshchi’s subjects ate breakfast, they ingested less food overall. And vice versa: when they skipped breakfast they ate more overall. They were anomalous. This was something that Dr Farshchi signposted himself, writing that his findings were ‘at variance with previous studies’. (The previous studies show, of course, that breakfast eaters, like the Cambridge team’s subjects, consume more calories.)
So Dr Farshchi’s findings cannot resolve the Cambridge researchers’ paradox, because the Cambridge team’s breakfast eaters ingested more food overall whereas Dr Farshchi’s breakfast eaters ingested less.
I hope I have not been unfair to the Cambridge scientists, whose papers are, rightly, widely read, and whose data can be trusted unreservedly, and who are scrupulously honest, but we do need to know if eating breakfast is good or bad for us, and if we adopt their paradox we have to conclude (in my summary of their logic) that:
to keep slim, eat more at breakfast and ensure your total food intake also goes up
whereas if we refuse to accept a paradox, then the data suggest that:
to keep slim, skip breakfast, which will lower your total food intake.
The choice is black or white, but the consequences may be life or premature death.
And though I totally respect the Cambridge scientists’ data, I do regret one set of facts they seem to have omitted: they appear to have excluded from their analysis all the subjects who died or fell ill over the 3.7 years they monitored them. But it is a principle in epidemiology that the most important potential end-point of an investigation is not a proxy measurement (such as obesity) but the end-point itself, namely death. The team might still have those data, and it would be good to see them published. Do they show if breakfast kills or cures?
Why were Dr Farshchi’s subjects anomalous?
Why were Dr Farshchi’s breakfast eaters eating less, overall, than the breakfast skippers? Or, to rephrase the question, why were the breakfast skippers eating more, overall, than the breakfast eaters?
Well, Dr Farshchi studied only ten women, whom we have to conclude were simply unrepresentative of the wider population. Different people can respond dramatically differently to the same food. Consider blood glucose. In 2015 two Israeli scientists published a comprehensive study on no fewer than 800 people, finding that ‘people eating identical meals present high variability in post-meal blood glucose responses.’11
Consider bread. There is a ninefold difference between different people’s blood sugar responses to breakfast bread, with some people registering only a pimple on the graph while others register a huge rise. Some people, remarkably, register higher levels of blood glucose after eating bread than after eating the equivalent amount of glucose itself. In some people, moreover, bananas raise blood glucose levels worryingly but cookies are completely safe, yet for other people the exact reverse is true. And for some people tomatoes are dangerous.
These variabilities should not have been surprising: in a classic experiment from 1990, a Quebec study isolated twelve pairs of young male twins, and for four months overfed all twenty-four men by 1,000 calories a day, almost as if they were geese on a pâté de fois gras production line. On average, the men gained 8.1 kg (18 pounds or 1¼ stones) but the range was considerable, from 4.3 kg to 13.3 kg.12 Intriguingly, though, each twin gained almost the same amount of weight as their fellow twin; i.e. different people’s metabolisms are very different indeed, and the differences are largely genetic.
People, in short, have inherited very different responses to food, so nutritional studies on only ten people will inevitably be overwhelmed by individuals’ quirks. Indeed, a later breakfast experiment by Dr Farshchi’s colleagues in Nottingham on twelve men found that the ‘combined energy intake [breakfast and lunch] did not differ between the breakfast and no-breakfast trials’,13 i.e., when those Nottingham scientists repeated their own experiment on twelve men, they got different results from when they’d performed it on ten women – with both sets of findings being at variance with previous studies. To get a solid breakfast finding, therefore, it may not be necessary to study 800 folk the way Segal and Elinav did, but equally we must view findings on ten or twelve subjects as only preliminary and potentially misleading, not definitive.
It was scrupulously honest of Dr Farshchi to admit to the anomalous nature of his experiment, but it is nonetheless depressing that his paper has been cited over 200 times (including by the Harvard scientists), and though I’ve not checked every paper that has cited it, every one I have checked has cited it to confirm a breakfast hypothesis that the data in the paper actually disprove. Dismaying.
The heroic breakfast guerrillas
It takes courage to flout the dominant paradigm, so let me here signpost the work of a small group of brave resisters.
David Allison: In 2013 David Allison and his colleagues from the University of Alabama at Birmingham reviewed ninety-two studies known to have reported on skipping breakfast. Their review had a dramatic title, ‘Belief beyond the evidence: Using the proposed effect of breakfast on obesity to show 2 practices that distort scientific evidence’, but their review lived up to the billing, showing that breakfast researchers regularly misrepresent not only their own results but also those of other researchers. So, for example, Allison reported that no fewer than 62 per cent of the papers he surveyed cited just one particular study in a ‘misleading’ fashion. Allison concluded that: ‘The scientific record is distorted by research lacking probative value and biased research reporting.’1
This conclusion was challenged by researchers from Harvard University’s School of Public Health, who argued that Allison had not disproved the suggestion that breakfast skipping caused obesity;2 to which Allison responded by saying he was not trying to disprove it, he was showing that no one had actually established the causation in the first place.3
In 2014, moreover, in a randomised controlled trial, Allison divided obese or overweight adults into three weight-loss groups, who either
ate breakfast every day
ate no breakfasts
ate however they wanted.
And after sixteen weeks there was no difference in weight between the three groups.4
In so doing Allison replicated a 1992 study from Nashville, Tennessee, which reported that when moderately obese women were put on identical weight-reduction diets, differing only in the provision or otherwise of breakfast (the breakfast skippers ate more at lunch and dinner to compensate for the skipped calories) there was no difference in the rate of weight loss.5
David Levitsky: It’s not only southerners who are seceding from the dominant paradigm. On 1 August 2014 David Levitsky of Cornell University, NY, wrote an editorial for the American Journal of Clinical Nutrition declaring war on breakfast. It was Levitsky who, with Carly Pacanowski, had shown (above) that breakfast does not induce satiety – rather, it increases food consumption – so Levitsky has been