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Published by World Advertising Research Center Farm Road, Henley-on-Thames, Oxon RG9 1EJ, UK Tel: +44 (0)1491 411000 Web: www.warc.com |
Vol.4, Issue 2 (2002) |
Stephanie
Lvovich
Ergo Communications
Obesity an important health problem globally. Over the last five years, the issue has climbed the list of political priorities and is now one of the most hotly discussed topics in business and political circles. Within this discussion, the advertising business is being accused of damaging the health of the nation by pushing 'inappropriate' food and drink onto consumers, promoting harmful dietary change, and bombarding children with messages that undermine parental authority and governments' positive eating messages.
Whilst intense media interest continues to bring the issues to the headlines, very few academics, journalists or politicians are actually looking at the scientific evidence relevant to the development of obesity – particularly childhood obesity – to see what the most important causes are, and whether advertising should be considered one of them. This article will examine two questions:
Obesity is a condition that occurs when energy intake exceeds energy output for extended periods of time. It is defined by the World Health Organisation (2000) as a Body Mass Index (BMI) of over 30. BMI is calculated by taking the individual's weight (kg) divided by the square of their height (m). Normal weights are in the range of BMIs from 18.5–25. Cut-off points for obesity are usually set at more than 30, for moderate obesity 30–35 and severe obesity 35–40.
Proponnett (1997) investigated European attitudes to physical activity and diet. Interviews were conducted with 1,600 children aged 8–15 in a pan-European study of France, Germany, Italy and the UK. The results showed that, across the four countries, 79% agree that exercise is just as important as the food you eat for staying healthy. The lowest was Germany, in which 67% agreed with this statement. Across the four countries 82% of the respondents disagreed with the statement that chocolate is OK to eat every day.
Research shows that physical activity in the UK is 50% lower than the recommended level. Similar figures are found throughout Europe. This factor appears to be the strongest indicator of obesity. Ludwig et al. (2002) suggest that a lifestyle characterised by lack of physical activity and excessive inactivity might cause obesity in children. Children engaging in the least vigorous physical activity in one study tended to be the most overweight.
Martinez-Gonzales et al. (1999) investigated diverging trends of decreasing energy intake and increasing prevalence of obesity. They suggest that physical inactivity and sedentary lifestyle may be one of the key determinants of the growing rates of overweight obesity in western populations.
Professional interviewers administered standardised in-home questionnaires to 15,239 men and women aged 15 years upwards. Energy expenditure during leisure time was calculated based on data on the frequency of and amount of time spent participating in various physical activities, assigning metabolic equivalents (METS) to each activity. Sedentary lifestyle was assessed by means of self-reported hours spent sitting down during leisure time.
In conclusion, they suggested that obesity and higher body weight are strongly associated with a sedentary lifestyle and lack of physical activity in the adult population of the European Union. Nonetheless, they are consistent with the view that a reduction in energy expenditure during leisure time may be the main determinant of the current epidemic of obesity.
Fogelholm et al. (1999) conducted a cross-sectional study of 129 obese and 142 normal weight children. They investigated differences in physical activity between normal-weight and obese children, as well as parent–child associations of obesity and physical activity.
The results showed that parent inactivity was a strong and positive predictor of child inactivity. Scores of parent activity were somewhat weaker predictors of child vigorous activity hours and total physical activity level. Child obesity was negatively associated with child habitual physical activity. In addition, parent obesity was another strong predictor of child obesity.
This study underscored the parents' role in childhood activity patterns and obesity, and found that the parent–child relationship of inactivity appeared to be stronger than that of vigorous activity. This therefore sends a message to parents: those who want to reduce their children's inactivity may have to pay attention to their own lifestyle.
Dr Kerney, Director, Institute of European Food Studies, assessed the attitudes of consumers from all member states of the EU towards physical activity. The findings indicated that people perceive food to be far more important for preventing weight gain than physical activity. When asked the most important influences on health, nutrition was ranked higher than physical activity. Smoking and stress were perceived as more important health influences than physical activity. A quarter of the EU consumers believed that unless physical activity resulted in weight loss they were not really benefiting from it, and 69% of people felt no need to alter their diets, believing them to already be healthy enough.
Family eating habits and food choices are the critical drivers in the tastes that children develop – particularly in young children. Despite some changes in the structure of the family, parents' approach to food and their food choices are key determinants of children's eating habits and taste preferences.
There is scientific consensus that the role of the family – its structure, food patterns and habits, and socio-economic status – is one of the most important in the development of obesity globally.
The primary agent of socialisation for the young, regardless of nationality, is the family. Johnson et al. (1991) suggested that repeated exposure to high fat foods is likely to encourage a 'taste' for them. Research on conditioning behaviour shows how parents' use of foods as rewards will affect children's 'taste' and how they view foods. Experts suggest that mothers influence the food preferences of their children as early as two years of age through their own food preferences. Foods that were disliked by mothers were not likely to be offered to children. The number of foods liked at age four years was the strongest predictor of the number of foods liked by age eight. Children were more likely to accept foods when they were introduced before the age of eight
[Journal of the American Dietetic Association (2002) 102, pp.1638–1647].Contemporary family habits are very different from those 25 years ago, and eating patterns reflect the change in the structure of the family, longer working hours, the boom in prepared foods to cater for today's workforce, and the increase in working mothers. Some scientists suggest that there has been an upheaval of the traditional family and that the nature of childhood is changing because of the influence of computers, career-minded women and families becoming a 'demographic unit' rather than a hierarchical structure. Today, more responsibility and decision-making is expected from children by their parents. An increase in advertising directed at children – for foods and other products – reflects this trend (Lang 1997).
The Saba et al. (1999) study was aimed at verifying the hypothesis that individuals belonging to different classes of BMI could show diversities in attitudes and beliefs toward the consumption of food containing fat. Nine hundred and seventy five subjects over 17 years of age with BMI values over 18.5 kg = m² were included in the study. The recruited families were asked to record their food consumption for seven days according to a mixed technique including the weighed inventory method and the individual daily record of food consumption. Each individual also completed a questionnaire containing questions on belief, attitude and intention items. All questions were related to the consumption of eight foods containing fats.
The main finding was an absence of differences in attitudes and beliefs towards foods containing fats between the two groups of normal weight and overweight subjects. The subjective measure of habit outweighed attitude in the impact on intention of consuming. The researchers concluded that attitudes and beliefs play a similar role in the choice of foods containing fats in the two groups of people considered. Habit was found to be an important predictor of behaviour for both the two groups of subjects. The importance of habits explains the difficulty experienced in modifying diets.
Experts suggest that since 1997 six genetic mutations that cause human obesity have been notified, all presenting in childhood (Ludwig et al. 2002). There are also other biological circumstances that distinguish people's susceptibility and weight gain on grounds of both sex and ethnicity (Rosner et al. 1998, McGarvy 1991).
Wardel et al. (2001) suggest children of obese parents have a substantially higher risk of adult obesity than children of lean parents. Adoption and twin studies have shown that this risk is largely genetic but the proximal mechanisms of the genetic risk are not known. Comparisons of energy intake or expenditure in children of obese and lean parents have produced mixed, but generally negative, results. An alternative hypothesis is that the early expression of obesity risk is through food and activity preferences, which provides a basis for later weight gain.
The aim of their study was therefore to compare food and activity preferences in a large sample of young children from obese and lean families. They found that children from the obese/overweight families had a higher preference for fatty foods in a taste test, a decreased liking for vegetables, and an eating style that fell more into the 'overeating-type'. They also had a stronger preference for sedentary activities, and spent more time in sedentary pastimes. There were no differences in speed of eating or reported frequency of intake of high-fat foods.
Scientific evidence suggests that, although obesity has not yet proven to be hereditary, there may be a genetic predisposition to become obese. Coupled with the predisposition and a certain environment, this may trigger obesity in some individuals. Some scientists suggest overweight parents create specific food environments for their children, since, in addition to their genetically transmitted predisposition to being overweight, fat parents often raise their children in an environment where fatty food is easy and encouraged (Fisher & Birch 1995). However, there is still disagreement as to whether genetics can be considered a key explanation for the serious trends in increased obesity levels globally.
Demographic characteristics of the family are also important in the development of obesity, although these tend to be more sensitive to address politically. In a review of 144 published studies on the subject, a pattern emerges where high socio-economic status (SES) is negatively correlated with obesity in developed countries for women. However the reverse pattern is found in developing societies. For men, women and children in developing societies there is a strong direct relationship between SES and obesity (Sobal & Stunkard 1989).
Sobal & Stunkard propose that the low prevalence of obesity in lower SES groups in developing societies could be a result of a lack of food or even famine, coupled with high energy expenditure as a result of labour-intensive work patterns, although more recent research suggests that there may be a connection between famine during childhood and obesity later in life.
Socio-economic factors have received most attention, but the data is inconclusive, with some studies in the USA and Europe showing an inverse relationship between socio-economic status and obesity prevalence, and studies from the UK, Denmark, Sweden and Italy showing no relationship. These unclear relationships within Europe may reflect, in part, inter-country differences in classification of socio-economic background, in sampling and in analysis.
To date there is no research that directly links advertising and the development of weight problems or obesity. There is little doubt that advertising does help sell products, but it is one way to communicate. The influence of advertising is limited and, in some cases, very small.
Marketers claim that family decision-making is based on two sets of processes. The first is the repertoire or portfolio of choices that are brought into the supermarket, in some cases as a 'shopping list' but mainly as a mental list of categories of purchase based on past experience. This consists of food categories such as 'cereals', 'fruit', 'vegetables', 'baked beans', and so on. The main considerations here will be need and cost, although some consumer behaviour researchers have argued that there are psychologically-based categories such as 'gifts to myself', which are there in order to spoil the consumer as self-gratifying luxuries, as well as those based on household economics.
The other set of processes is based on which brand to choose within a particular category – and it is here that advertising and promotional activity has a major role to play in persuading the consumer to switch from brand X to brand Y or to stay with brand Y as one's favourite.
There is a significant and growing literature on the condition of obesity. Today, the literature confirms that obesity is multi-factorial in nature. That is, there is a wide range of factors contributing to the increasing levels of obesity globally. These include socio-economic status, family structure, family food purchasing and tastes, genetics, physical activity levels and so on.
Today, there is no agreement to what the root causes of obesity are and if, in fact, there is any one factor that contributes to the development of it. There is agreement, however, that there is interplay between many factors, although the exact nature of this interplay is unclear. This has led to the development of phrases like 'obesogenic environment', which seek to capture the range of factors impacting modern lifestyles and food choices.
Based on a reading of the literature, it appears clear that there is no evidence for a direct causal relationship between food advertising and obesity levels. There is increased interest by academics in linking TV watching with the development of obesity, although linking advertising within this context would be dubious, as such an examination would focus on the lack of physical activity (substituted by TV watching), rather than the effect advertising has on eating behaviour, which is at the root of the accusations facing the advertising business.
Fisher, J.A., & Birch, L.L. (1995) Fat preferences and fat consumption of 3–5 year-old children are related to parental adiposity. Journal of the American Dietetic Association, 95, pp. 759–764
Fogelholm, M., Nuutinen, O., Pasanen, M., Myöhänen, E. & Säätelä, T. (1999) Parent – child relationship of physical activity patterns and obesity. International Journal of Obesity 23 (12)
Johnson, S.L., McPhee, L., & Birch, L.L. (1991) Conditioned preferences: young children prefer flavors associated with high dietary fat, Physiology and Behaviour, 50, pp.1245–1251
Lang, S. (1997) Why tastes change. In G. Smith (ed.). Children's Food Marketing and Innovation. London: Chapman & Hall, pp. 49–68.
Ludwig, D., Ebbeling, G.C. & Pawlak, D. (2002) Childhood obesity: public health crisis, common sense cure, The Lancet, 360, 10th August, p 473
Martinez-Gonzales, M.A. et al. (1999) Physical inactivity, sedentary lifestyle and obesity in the European Union. International Journal of Obesity, 23, pp. 1192–1201.
McGarvy, S.T. (1991) Obesity in Samoans and a perspective on its etiology in Polynesians. American Journal of Clinical Nutrition, 53, pp. 1586S–1594S
Proponnet, J.P. (1997) Children's views on food and nutrition: a pan-European study. In G. Smith (ed) Children's Food Marketing and Innovation. London: Chapman & Hall, pp. 192–253.
Rosener, B., Prineas, R., Loggie, J. & Daniels, S.R. (1998) Percentiles for body mass index in US children 5–17 years of age. Journal of Pediatry 132, pp. 211–22
Saba, A. et al. (1999) Attitudes towards food containing fats in subjects of different body size. International Journal of Obesity. 23, pp. 1160–1169.
Sobal, J. & Stunkard, A.J. (1989) Socioeconomic status and obesity: a review of the literature. Psychological Bulletin, 105, pp. 260–275.
Wardel, J. et al. (2001) Food and activity preferences in children of lean and obese parents. International Journal of Obesity, 25, pp. 971–977.
WHO Consultation on Obesity (2000) Obesity: Preventing and Managing the Global Epidemic. Geneva: WHO.
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