signals. So Brian Wansink of the Cornell University Food and Brand Laboratory reported in his 2006 book Mindless Eating that when researchers from Pennsylvania State University:
gave three- or five-year-old children either medium-size or large-size servings of macaroni and cheese, the three-year-olds ate the same amount regardless of what they were given. They ate until they were full and then they stopped. [But] the five-year-olds rose to the occasion and ate 26 percent more when they were given bigger servings. Almost exactly the same thing happens to adults. We let the size of the serving influence how much we eat.5
In her 2011 book Eat What You Love, Love What You Eat Dr Michelle May listed the social and psychological signals that can override satiety in encouraging us to overeat.6 These include loneliness, depression, anxiety, stress and boredom. Or, in the words of Comic Book Guy from the 1997 episode of The Simpsons (#8.17), ‘My Sister, My Sitter’: ‘Loneliness and cheeseburgers are a dangerous mix.’
Distraction, too, can be a major eating stimulant: a recent overview of twenty-four separate research papers concluded that people who eat while being distracted (munching crisps while watching television, say) increase their food intake on average by 76 per cent.7 This is because distracted eaters not only eat mindlessly but also retain little memory of having eaten, so they approach their next meal assuming they must be hungry. There is wisdom behind the old injunction of ‘not eating between meals’.
Another social signal is company: in a series of studies for which he is rightly well known, John de Castro reported that, if you eat with one other person, your consumption goes up by 35 per cent; if you eat with three other people, your consumption goes up by 75 per cent; and if you eat with six other people your consumption goes up by 96 per cent.8 Which is why Wansink wrote in Mindless Eating that weight ‘can be contagious’.9
And we humans are not the only social animal whose eating is stimulated by company: as long ago as 1929 it was discovered that, when a solitary chicken was replete and had stopped eating, the admission of another chicken into its cage would prompt it to start eating again.10 The same behaviour is true of pigs, fish, rats, gerbils, puppies and primates. Social animals eat socially. Brian Wansink has even shown that the amount of food we order in a restaurant is influenced by the mass of the waiter: ‘diners were … four times more likely to order desserts … when served by heavy wait staff with high body mass indices.’11
Our species has been honed by aeons of evolution to seek social approval, so our eating is determined as much by our social and psychological choices as by our satiety, which we can override in daily practice.
(In this book I follow academic fashion in describing the extraordinary contemporary incidence of obesity and diabetes as ‘epidemic’ or ‘pandemic’. Originally, epidemics and pandemics were defined as diseases that spread from person to person, yet because overeating is socially transmittable, the use of the terms to describe obesity and diabetes may be defensible.)
An exception: Although humans generally eat more in company, a Vanderbilt University research group showed in a ‘get-acquainted’ session in a psychology laboratory that human females – unlike human males – will snack up to 75 per cent less in the presence of a desirable member of the opposite sex, which caused the researchers to speculate on the role of feminine self-presentation in the development of anorexia.12 This female trait was satirised by Aldous Huxley in chapter 19 of his 1921 novel Crome Yellow:
He noticed with surprise and a certain solicitous distress that Miss Emmeline’s appetite was poor, that it didn’t, in fact, exist. Two spoonfuls of soup, a morsel of fish, no bird, no meat, three grapes – that was her whole dinner …
‘Pray, don’t talk to me of eating,’ said Emmeline, drooping like a sensitive plant. ‘We find it so coarse, so unspiritual, my sisters and I.’
But some time later the protagonist finds a secret door, which he opens to find the sisters tucking into a good lunch. The protagonist promptly blackmails one of the sisters, Georgiana, into marrying him.
Studies on populations generally find that people who eat breakfast are thinner than people who skip it.1 Yet those self-same studies generally also find that people who eat breakfast consume more calories over the course of the day than do skippers. How can we reconcile these data?
Well, one of the reasons people skip breakfast is that they’re dieters. And who diets? Large people. So an Australian survey of 699 13-year-olds, 12 per cent of whom skipped breakfast, found that girls who believe themselves to be fat will go on weight-loss diets, and they will do so in part by skipping breakfast.2
The girls in that Australian study may, of course, have had false body images, and they may not have been large, but a study on female college students in North Carolina found that 48 per cent of the obese ones had skipped breakfast, as opposed to only 40 per cent of the overweight ones and just 27 per cent of the normally weighted ones.3 So large people do indeed skip breakfast.
That particular North Carolina study covered only 166 subjects, so it missed being statistically significant (p<0.09 in the jargon), but multiple surveys have confirmed that skipping breakfast is a common reaction to overweight and obesity.4 Consequently, large people will diet and will lose weight but – and here comes a key point – dieters generally fail to keep down their weight, and in so-called yo-yo dieting they tend to revert to being large.5 So as people cycle between:
being large and so losing weight by skipping breakfast
being slim and so eating breakfast again
we have found one resolution to the breakfast/body weight paradox. I.e. when people are large they skip breakfast and eat less (so largeness is associated with skipping breakfast) but when people have slimmed down they eat breakfast and other meals again and, unfortunately, put the weight back on (so slimness is associated with eating breakfast). But it’s not the eating of breakfast that determines weight, it’s weight that determines the eating of breakfast. I.e., it’s not:
eat breakfast → consume more calories → paradoxically be slim
or
skip breakfast → consume fewer calories → paradoxically be large
rather it’s:
be
