I’m not saying that body weight isn’t mostly a function of calories in and calories out. I happened to love physics in school and I don’t think I’d believe anyone who claimed that the human digestive system operated outside of the rules of thermodynamics. Rather, I think that we start in the wrong place with the story. The attitude in the media, pretty generally, seems to say, ‘if only fat people could have a bit of self control and reduce the number of calories they eat, they’d have no problem.’
My feeling is that being overweight nowadays has a lot more to do with our environment, with social pressures, with the availability of food, with advertising and with our psychological relationship to food, than it has to do with grammes of fat in our diets. It’s my premise that diet advice about eating this or that food, and banning these and those foods, locates the problem squarely in the food itself. Chocolate cake is bad food. And yet I know very healthy, thin people who sometimes eat chocolate cake.
I think a big clue lies in our information culture and the way we use our attention. ‘The information age’ has become cliché, but its over-use makes it no less true. Information doesn’t just come in the form of crowd-sourced Wikipedia entries. Information is attached to everything nowadays in ways undreamed of by our grandparents. The Internet is a culprit in the provision of excess information of course, but other media share the blame equally. My partner and I own a huge TV, three times bigger than the ones we each had when we were growing up. Our TV has a couple of hundred channels. And we don’t subscribe to anything more than the basic satellite package. We’re not rich. We’re not TV addicts. And yet there it is, taking up a huge chunk of space in our living room, pumping our lives full of distracting information hour after hour, day after day.
TV advertises food and diet programmes, of course, but there are sources of information even more intimately wound up with food. My grandparents bought cheese from a corner shop that stocked just one type at a time. When my parents were my age, they could choose between half a dozen types. Now, what does your usual supermarket look like? How many cheeses do you chose from? How many of them have nutrition labels? How many have little red-green traffic light symbols on the front?
I’m not drawing your attention to the choice here … well, that too … but look at the change in the information load! My parents’ generation had cheese choice when they were my age, but it was based on broad types of cheese from different parts of the world—Cheddar, Red Leicester, Brie. They may have had the choice between a couple of brands of Cheddar, maybe, but these brands would typically be competing on taste. Nowadays, this cheese is telling you, right on the wrapper, that it’s got 17% less saturated fat than that one, and that the one over there has less salt.
We now have many extra sources of information and data in our lives, from TV and Twitter to newspapers and noodle labels. I’ve become convinced that these extra sources of information are not generally very helpful in keeping our diets healthy or our bodies thin.
What’s more, as I’m reading the literature on the psychology of eating and body weight, it looks like there’s sound scientific evidence that this extra information load doesn’t help us make good choices.
Dr Tanja Kral, and colleagues, from Pennsylvania State University, conducted a study where forty normal weight women consumed their meals in laboratory settings for several days. They were given food prepared carefully to have higher or lower energy density (calories per gramme). For example, the apple pie had more of the relatively healthy apple filling, or more of the pastry, depending on which group they were in. The women were sometimes told about the energy density of the food, and sometimes not. Knowing that this was an especially fatty, calorie-rich apple pie didn’t significantly alter how many calories the women ate. The labels didn’t seem to help them manage their eating behaviour.
I would have liked to see this study done with men and women who were actively trying to loose weight, but the take-home message is interesting. Food labelling might not help us as much as we like to imagine.