Eating Behaviour

Eating Behaviour

1. Attitudes to Food

   • Most of us take food for granted, even taking into account the odd food fad or healthy eating regime.
   • However, for a substantial number of people, their attitudes to food and the consequent eating behaviours might be described as "disordered."
   • What distinguishes "disordered" eaters from "faddy" eaters is the purpose and consistency of the behaviour and whether or not the person maintains some degree of control over their eating behaviour.
   • When we begin to use food to resolve an underlying emotional issue, for example, there is a problem.
   • Where these distinctive attitudes to food and eating come from is open to question, so this essay will examine some possible explanations.
   • Social learning
     • Social learning theory emphasises the impact that observing other people (i.e. models) has on our own attitudes and behaviour.
     • Parental modelling
       • One way in which children acquire their eating behaviour and attitudes to food is by observing the behaviour of their parents.
       • Parental attitudes to food inevitably affect children because parents control the foods bought and served in the home.
       • However, research also suggests an association between parents' and children's attitudes to food generally.
       • Brown and Ogden, 2004
         • For example, Brown and Ogden reported consistent correlations between parents and their children in terms of snack food intake, eating motivations and body dissatisfaction.
     • Media effects
       • The role of social learning is evident in the impact of television and other media (such as magazines) on attitudes to eating.
       • MacIntyre et al, 1998
         • MacIntyre found that the media have a major impact both on what people eat, and also their attitudes to certain foods.
         • However, the researchers also state that many eating behaviours are limited by personal circumstances such as age, income and family circumstances.
         • Thus, people appear to learn from the media about healthy eating, but must place this information within the broader context of their lives.
         • Jamie Oliver, 2008
           • It was precisely this problem that led chef Jamie Oliver to set up his BBC "Ministry of Food" experiment in 2008.
     • Research support
       • Meyer and Gast, 2008
         • The importance of social learning in attitudes to food was demonstrated in their study.
         • They surveyed 10-12 year old boys and girls and found a significant positive correlation between peer influence and disordered eating.
         • The 'likeability' of peers was considered the most important factor in this relationship.
         • Birch and Fisher, 2000
           • The role of social learning is also supported in their study of mothers and daughters.
           • They found that the best predictors of the daughters' eating behaviour were the mothers' dietary restraint and their perception of the risks of the daughters becoming overweight.
     • Much more than learning
       • A social learning explanation of eating behaviour focuses explicitly on the role of fashion models in influencing the food attitudes of young people.
       • However, attitudes to food are clearly a product of much more than social learning alone.
       • Evolutionary explanations of food preferences for example, suggest that our preference for fatty and sweet foods is a direct result of an evolved adaptation among our distant ancestors over two million years ago.
   • Cultural influences
     • Much of the research into attitudes to food and eating behaviour has focused on body dissatisfaction, i.e. negative feelings and cognitions about the body that influence people's attitudes toward their eating behaviour.
     • The causes of body dissatisfaction and the consequent influence on eating behaviour include the following.
     • Ethnicity
       • Powell and Khan, 1995
         • Research suggests that body dissatisfaction and related characteristic of white women than black or Asian women.
         • Ball and Kennedy, 2002
           • Ball and Kennedy studied over 14,000 women between 18-23 in Australia.
           • Research showed that for all ethnic groups, the longer the time spent in Australia, the more the women reported attitudes and eating behaviours, similar to women born in Australia (known as the "acculturation effect.")
       • Commentary
         • Although some research has found that a preoccupation with dieting and disordered eating are more common among white females than black or Asian women, other studies have found the complete opposite.
         • Mumford et al, 1991
           • They found that the incidence of bulimia was greater among Asian schoolgirls than among their white counterparts.
           • Striegel-Moore et al, 1995
             • Similarly, they found more evidence of a 'drive for thinness' among black girls than among white girls.
     • Social class
       • A number of studies have found that body dissatisfaction, dieting behaviour and eating disorders are more common in higher-class individuals.
       • Dornbusch et al, 1984
         • For example, Dornbusch surveyed 7000 American adolescents, and concluded that higher-class females had a greater desire to be thin, and were more likely to diet to achieve this, than their lower-class counterparts were.
         • Goode et al, 2008
           • A recent study used data from the 2003 Scottish Healthy Survey and established that, in general, income was positively associated with healthy eating.
       • Commentary
         • Research suggests that the relationship between social class and eating behaviour is not that straightforward.
         • Story et al, 1995
           • In direct contrast to Dornbusch's study, Story found that in a sample of American students, higher social class was related to greater satisfaction with weight and lower rates of weight control behaviours such as vomiting.
           • Other studies have no relationship between social class and weight dissatisfaction, the desire for thinness and eating disorders.
   • Mood and eating behaviour
     • Some explanations of eating behaviour, particularly of binge-eating, see it as a temporary escape from negative mood (such as sadness or anxiety).
     • Binge-eating
       • Research has shown that individuals with bulimia nervosa complain of anxiety prior to a binge.
       • Davis et al, 1988
         • Self-monitoring studies have shown that one hour before a binge, bulimic individuals had more negative mood states than one hour before a normal snack or meal.
         • The same relationship between low mood and binge-eating appears to hold for sub-clinical (below the threshold for clinical diagnosis) populations.
         • Wegner et al, 2002
           • Wegner had students record their eating patterns and mood states over a two-week period.
           • Binge days were characterised by generally low mood compared to non-binge days, but there was no difference in mood before and after a binge.
           • This suggests that although low mood may make binge-eating more likely, it does not alleviate the low mood state.
       • Commentary
         • Binging and reinforcement
           • A number of studies have found that a period of lowered mood or anxiety precedes an episode of binge-eating, suggesting that depressed mood somehow causes the onset of binge-eating.
           • Although a binge-eating episode might offer immediate gratification for the individual, any reinforcement is fleeting at best, and many studies report a drop in mood immediately after the binge.
           • It is unclear, however, why a binge-eating episode might be reinforcing for the individual, particularly as any benefit appears to be fleeting at best, and many studies report a mood decrement immediately after the binge.
     • Comfort-eating
       • For many of us, the experience of eating junk food when feeling a little low strikes a familiar chord. Garg's study offers an explanation for this particular relationship between mood and eating behaviour.
       • Garg et al, 2007
         • Low mood and comfort-eating
           • Garg et al. observed the food choices of 38 participants as they watched either an upbeat, funny movie (Sweet Home Alabama) or a sad, depressing one (Love Story).
           • Participants were offered buttered popcorn and seedless grapes throughout the films.
           • Those watching the sad film consumed 36% more popcorn than those watching the upbeat film, but the upbeat film group ate far more grapes than the other group.
           • Garg claims that people who feel sad or depressed want to "jolt themselves out of the dumps", therefore they are more likely to go for a snack that tastes good to give them a sudden rush of euphoria.
           • Happy people want to extend their upbeat mood and so choose healthy foods.
           • However, when participants were presented with nutritional information about the foods (among other information) prior to viewing, consumption of the relatively unhealthy foods dropped dramatically.
           • Perhaps, suggest the researchers, when we eat to comfort ourselves, we would do well to check the nutritional information on the foods we indulge in.
       • Chocolate
         • Chocolate has long been seen as the ultimate comfort food. Our attitudes towards chocolate appear to be influenced by its ability to popular claims that it can lift our mood.
         • Parker et al, 2006
           • However, a recent study by Parker found that, although chocolate has a slight antidepressant effect for some people, when consumed as an emotional eating strategy (e.g. when feeling down),it is more likely to prolong rather than alleviate the negative mood, particularly if used repeatedly.
   • Gender bias
     • Most studies have concentrated on women's attitudes to eating behaviour, particularly in terms of body dissatisfaction and disordered eating.
     • Siever, 1994
       • However, studies have also shown that in men, homosexuality is more of a risk factor in the development of disordered eating attitudes and behaviour, including body dissatisfaction, higher levels of dieting, and a greater incidence of bulimic symptoms than in heterosexual men.
       • These findings have been attributed to the male gay subculture, which places great emphasis on the lean, muscular body ideal.
   • Generalisability
     • The studies shown here come from a variety of groups, some clinical (i.e. diagnosed with an eating disorder such as bulimia nervosa), some with sub-clinical conditions, and others who represent a non-clinical population who experience a temporarily depressed mood (e.g. comfort-eaters).
     • This puts limitations on the degree to which we can generalise from one group to another, and therefore the degree to which these studies offer a universal understanding of causal factors in eating behaviour.
   • Cultural differences
     • Rozin et al, 1999
       • They explored the way that food functions in the minds and lives of people from four cultures.
       • Adults and college students from Belgium, France, USA and Japan completed a survey dealing with food-related issues including beliefs about the diet-health link, consumption of 'healthy' foods (e.g. reduced in salt or fat) and satisfaction with the healthiness of their own diets.
       • In all areas except beliefs about the importance of diet for health, they found substantial cultural (and usually gender) differences.
       • In all four countries, females, more than males, showed a pattern of attitudes that was more like the American and less like the French (i.e. food associated with health rather than with pleasure).
       • The researchers concluded that these differences may influence health and may partially account for national differences in rates of cardiovascular disease.

2. Impact of Dieting

   • A consequence of body dissatisfaction is the need to diet as an attempt to modify body size and shape to fit in with perceived cultural ideals. 
   • Three basic forms of dieting have been identified. 1) restricting the total amount of food eaten. 2) refraining from eating certain types of food. 3) avoiding eating for long periods of time.
   • The potential to influence weight change then becomes the primary (in many cases the exclusive) criterion for food selection.
   • Research, such as the Kern et al. study on the right, suggests that for some people, dieting will always be difficult because of a genetic predisposition to obesity.
   • Higgins and Gray, 1999
     • Dieting may also be associated with a particular mentality or mindset, characterised by a pervasive concern with body size, shape and weight.
   • Restraint Theory
     • Restrained eating has become synonymous with dieting. 
     • Klesges et al, 1987
       • Research suggests that as many as 89% of the female population in the UK consciously restrain their food intake at some point in their lives.
     • Herman and Mack, 1975
       • Restraint theory was developed as an attempt to explain both the causes and consequences associated with the cognitive restriction of food intake. 
       • Herman and Mack suggest that attempting not to eat actually increases the probability of overeating.
       • Wardle and Beales, 1988
         • They carried out an experiment to test this prediction. Their study showed that the overeating shown by many dieters is actually caused by their attempt to diet.
     • Boundary model
       • Herman and Polivy, 1984
         • In an attempt to explain why dieting might lead to overeating, Herman and Polivy developed the boundary model.
         • According to this model, hunger keeps intake of food above a certain minimum, and satiety (satisfaction of hunger) works to keep intake below some maximum level.
         • Between these two levels, psychological factors have the greatest impact on consumption.
         • Dieters tend to have a larger range between hunger and satiety levels as it takes them longer to feel hungry and more food to satisfy them.
         • In addition, restrained eaters have a self-imposed desired intake. Once they have gone over this boundary they continue to eat until they reach satiety, i.e. beyond the maximum level imposed as part of their diet.
         • Ogden, 2007
           • See textbook for comparison of boundaries for normal and restrained eaters by Ogden
       • Implications for obesity treatment
         • Restraint theory suggests that restraint leads to excess, yet the treatment of obesity commonly recommends restraint as a solution to excessive weight gain.
         • However, failed attempts to diet can leave obese individuals depressed, feeling a failure - and unable to control their weight.
         • Limited relevance
           • Restraint theory proposes an association between food restriction and overeating.
           • Ogden, 2007
             • However, Ogden points out that although dieters, bulimics and some anorexics report episodes of overeating, the behaviour of restricting anorexics cannot be explained using this theory.
             • If trying not to eat results in overeating, says Ogden, then how do anorexics manage to starve themselves?
         • Ogden, 1994
           • Although obesity may not necessarily be caused by overeating, overeating may be a consequence of obesity if restraint is recommended as a treatment.
   • Role of denial
     • Research in cognitive psychology has shown that attempting to suppress or deny a thought frequently has the opposite effect, making it even more prominent.
     • Theory of ironic processes of mental control
       • Central to any dieting strategy is the decision not to eat certain foods, or to eat less less of them.
       • This results in a similar state of denial to the example above, as dieters try to suppress thoughts about foods deemed to be 'forbidden' as part of their diet.
       • According to this theory, therefore, attempts to suppress thoughts of foods such as pizza and chocolate only serve to increase the dieter's preoccupation with the very foods they are trying to deny themselves.
       • As soon as a food is denied, therefore, it simultaneously becomes more attractive.
       • Research support
         • Soetens et al, 2004
           • Softens provided experimental support for this theory. Participants were divided into restrained and unrestrained eaters, and the restrained group was then subdivided into those who were either high or low on disinhibition.
           • The disinhibited restrained group (i.e. those who tried to eat less but who would often overeat) used more thought suppression than the others groups, and also showed a rebound effect (i.e. thought more about food) afterwards.
           • This study shows that restrained eaters who tend to overeat try to suppress thoughts about food more often, but when they do, think more about food afterwards.
       • Limited experimental effects
         • Wegner, 1994
           • Wenger admits that the 'ironic effects' observed in research are not particularly huge.
           • As experimental effects go, they are detectable but far from overwhelming.
           • However, as such effects may underlie more serious pathological forms of eating behaviour, their influence could be considered overwhelming in terms of everyday human cost.
     • Wegner et al, 1987, 1994
       • For example, Wegner asked some participants not to think about a white bear, but to ring a bell if they did, and others to think about the bear. 
       • Results showed that those told not to think about the bear rang their bells far more often than participants instructed to think about the bear. 
       • Wegner refers to this phenomenon as the "theory of ironic processes of mental control" because it represents a paradoxical effect of thought control, i.e. denial often backfires.
   • Key to a successful diet
     • Redden, 2008
       • So far we have concentrated on the reasons why dies fail, but recent research by Redden suggests that the secret of successful dieting lies in the attention we pay to what is being eaten.
       • He claims that people usually like experiences less as they repeat them. When it comes to dieting, this makes it harder to stick to a particular regime.
       • To overcome this, suggests Redden, instead of thinking 'not another salad' we should focus on the details of the meal (e.g. rocket, tomato, apple, etc.).
       • By focusing on the specific details of each meal, people get bored less easily and so are better able to maintain their diet.
     • Jelly beans experiment
       • To test this theory, Redden gave 135 people 22 jelly beans each, one at a time.
       • As each bean was dispensed, information about it was flashed onto a computer screen.
       • One group saw general information (e.g. 'bean number 7') whereas the other group saw specific flavour detail (e.g. 'cherry flavour number 7').
       • Participants got bored with eating beans faster if they saw the general information, and enjoyed the task more if they saw the specific flavour details.
     • Anti-dieting programmes
       • Concerns about the effectiveness and potentially damaging effects of many diet programmes has led to the development of programmes aimed at replacing dieting with conventional healthy eating.
       • These programmes emphasise regulation by body hunger and satiety signals and the prevention of inappropriate attitudes to food (e.g. comfort-eating or food avoidance).
       • Higgins and Gray, 1999
         • A meta-analysis of the effectiveness of anti-dieting programmes found that participation in these programmes was associated with improvements in both eating behaviour and psychological wellbeing and with weight stability rather than weight change.
   • Restraint and overeating
     • Wardle and Beales, 1988
       • Waddle and Beales randomly assigned 27 obese women to either a diet group (focusing on restrained eating patterns), an exercise group, or a non-treatment group for seven weeks.
       • At weeks four and six, all participants were assessed under laboratory conditions.
       • At week four, food intake and appetite were assessed before and after a 'preload' (i.e. a small snack such as a milkshake or chocolate bar). At week six, food intake was assessed under stressful conditions.
       • Results showed that at both assessment sessions, women in the diet condition ate more than women in the exercise and non-treatment groups.
   • Limitations of anecdotal evidence
     • Many studies of dieting success or failure rely on the personal accounts of individuals i.e. anecdotal evidence.
     • Such evidence is often used to justify claims concerning particular dieting strategies. However, anecdotal evidence has a number of problems that properly controlled scientific studies do not have.
     • The main limitation is that memory is not 100% accurate, nor is assessment of the success or failure of dieting entirely objective, which creates problems for the reliability of the evidence provided by personal accounts and anecdotes.
   • Cultural differences in obesity
     • Research suggests that some cultural groups find it harder to diet successfully because of a natural inclination to obesity.
     • Park et al, 2001
       • For example, Asian adults are more prone to obesity than Europeans.
     • Misra et al, 2007
       • Likewise, there is evidence that Asian children and adolescents have a greater central fat mass when compared with Europeans and other ethnic groups.
   • Does dieting make you dumb?
     • Green (cited in Somer, 1999)
       • Studied the effects of diet on mental performance.
       • Fifty-five women between the ages of 18 and 40, some on weight-loss diets, some not, were given a task involving recognising and responding to sequences of three odd or three even numbers.
       • Compared to the non-dieting women, those on the very low-calorie diets processed this information more slowly and took longer to react.
       • Green suggests that the preoccupation with body shape, food restriction and the dieting experience typical of someone on a 'crash diet' may in some way overload the dieter's mental capacity.
   • Free will or determinism - born to be fat?
     • It is likely that a number of genetic mechanisms exert influence on weight.
     • One is the gene that codes for lipoprotein lipase (LPL), an enzyme produced by fat cells to help store calories as fat.
     • If too much LPL is produced, the body will be especially efficient at storing calories. LPL also makes it easier to regain lost weight.
     • Kern et al, 1990
       • In one study, nine people who lost an average of 90 pounds had their LPL levels measured before dieting and again three months later.
       • Levels of LPL rose after weight loss, and the fatter the person was to start with, the higher the LPL levels were, as though the body was fighting to regain the weight.
       • The researchers believe that weight loss activated the gene producing the enzyme, which might explain why it is easier for a dieter to regain lost weight than for someone who has never been obese to put weight on.