Why do some people get fat?
Professor John Coveney, convenor of the International Research Collective of Food, Culture, Health, discusses how social eating research can illuminate our understanding of the age-old universal question of why some people get fat....
Why do some people get fat? This question may be simple enough to answer. But it is a different question from why do people get fat? This last question speaks to what we think we know about food energetics and the relationship between energy in (food and drink) and energy out (physical activity, basal metabolic activity etc). From the time of Wilbur Atwater, the father of modern nutrition, we have developed an understanding of the calorific nature of food and energy balance.
But the first question still stands: why do some people get fat? Of course, we know that at the general level overweight or obesity are caused by food much food energy in and too little activity energy out. But this does not answer our question as to why some people get fat. To answer this question, we need knowledge other than straight calorimetrics. We need to know how people spend their lives, how they eat and what they eat. We need to know how people work, play, and spend time in various activities. That is to say, we need to know what people do, where they do what they do, and why they do what they do. Do we have this information already? Well, yes and no. We do have information that has been collected on what people eat. From time to time we hear about food surveys by governments or private industry. This information is generally collected by people themselves and or through interviews where participants are questioned about what they eat and how much of it they eat.
As a clinical dietitian for many years I collected ‘diet histories’ as these records were called. On many occasions I could not reconcile what people were telling me they ate with what was in front of me. That is to say, I could not understand why my informant was telling me that they ate like a bird and yet they were tipping the scales with a BMI more than 30 (desirable BMI is between 20-25). Could it be that the information I was collecting was not entirely the whole picture? Could it be that what my informants told me had been selected so as to look ‘normal’? The answer is: probably. We know from experiments that have surreptitiously recorded people eating and then asked them what they ate find a lot of people ‘under report’. And it seems that people who are overweight are more likely to reveal less about their diet. So ‘yes’, we do have information about what people eat, but ‘no’ we can’t rely on it because it is under reported.
Trying to get a picture of how people do what they do is even more difficult because of memory recall and bias towards a more ideal. What is lacking is an in-depth picture of how people live their lives, what they eat, where they eat etc. Also lacking is a similar picture but for physical activity. The absence of an close up view of people’s lives is missing from this picture because there is little information collected through observation. In other words, most of what we know in this area is arrived from what people choose to tell us, not what we have observed. To obtain an observation view we need to use methods that go further than interviews, food records, food histories, activity records etc. We need to be in the space of the participants lives so that we can see, observe and record from the outside - the etic perspective to use the jargon from anthropology. Why are we not doing this kind of information gathering? Partly because of a fall from favour of these techniques, partly because it is expensive to spend bulk time ‘in the field’, and partly because our ethics approval processes do not look upon ‘up close and personal’ forms of data collection positively. Problems are often raised by ethics committees about field work observation becoming an intrusion into people’s lives, an imposition of participants and their families, and a breach of (ethical) respect. Thus, the distance between participants and researchers has increased. And with that has come a blurring of what useful information we can collect, and the consequences are, well… no, actually, we do not know why some people get fat because we do not have any idea of minutiae in daily lives – people’s quotidian events– which would provide a picture of the habits and routines that lead to food choices and physical activity patterns that make people fat.