Social variations in nutritional habits and their trends in (PDF)

Nordic School of Public Health Social variations in nutritional habits and their trends in Lithuanian adult population Vilma Kriaucioniene Master of Public Health MPH 2006:24  Social variations in nutritional habits and their trends in Lithuanian adult population. © Nordic School of Public Health ISSN 1104-5701 ISBN 91-7997-157-1  MPH 2006:24 Dnr U 12:03:299 Master of Public Health – Essay – Title and subtitle of the essay Social variations in nutritional habits and their trends in Lithuanian adult population Author Vilma Kriaucioniene Author's position and address Junior Researcher, Department of Preventive Medicine, Institute for Biomedical Research, Kaunas University of Medicine, Eiveniu 4, LT-50009, Kaunas, LITHUANIA Date of approval 2006-08-29 Supervisor NHV/External Janina Petkeviciene No of pages 41 Language – essay English Language – abstract English ISSN-no 1104-5701 ISBN-no 91-7997-157-1 The aim of this study was to assess the socio-demographic variations in nutritional habits and their trends over the last decade in Lithuanian adult population. Methods: Six health behaviour surveys were carried out within the international FINBALT HEALTH MONITOR project between 1994-2004. For every survey the national random sample of 3000 inhabitants aged 20-64 was taken from the National Population Register. The study material was collected through mailed questionnaires covering sociodemographic characteristics and some nutrition habits. Response rates ranged from 61.7% to 74.4%. Education was measured using five educational levels. The respondents were categorized into three groups: persons with incomplete secondary education (primary or incomplete secondary), secondary (secondary or vocational), and university education. The degree of urbanization was based on the administrative classification of the places of residence. The respondents were grouped as living in cities, towns, or villages. The effect of age, level of education, place of residence, and marital status upon nutritional habits was evaluated using multifactor logistic regression analysis that was carried out separately for men and women. Results: Positive trends in nutritional habits were observed between 1994-2004 in Lithuania. The diet of the Lithuanian population tended to become closer to the WHO recommendations for healthy nutrition. The intake of animal fat decreased. Almost a half of population replaced butter on bread by low fat margarine. The proportion of men using vegetable oil for cooking increased from 31.1% in 1994 to 82.6% in 2004, and the proportion of women – from 47.7% to 89.4, respectively. The consumption of fresh vegetables, fruit, and dark bread has increased. Although all social groups of the Lithuanian population have changed their diet, social differences in nutrition habits still remained significant. Women, highly educated persons and urban population have healthier diet than men, people with lower education and rural population. The odds ratio of using vegetable oil among men with university education was higher by 98% and among women – by 67% than that among persons with incomplete secondary education. The respondent with university education were more than twice as likely as low educated people to consume fresh fruits daily. The proportion of persons drinking whole milk was much higher in villages (OR 4.80 (CI 4.0-5.8) for men and 7.33 (CI 6.1-8.8) for women) compared to cities. Conclusions: Existing social differences in nutritional habits should be considered in the programs for the promotion of healthy nutrition and implementation of Lithuanian Food and Nutrition Action Plan development. Key words nutritional habits, socioeconomic status, food frequency questionnaire, trends. Nordic School of Public Health P.O. Box 12133, SE-402 42 Göteborg Phone: +46 (0)31 693900, Fax: +46 (0)31 691777, E-mail: [email protected] www.nhv.se  TABLE OF CONTENTS Introduction and background ………………………………………………3 Aim …………………………………………………………………………....7 Specific objectives ……………………………………………………………7 Materials and methods ………………………………………………………8 Results ………………………………………………………………………..10 The trends in the nutritional habits of the Lithuanian population in 1994-2004.....................................................................................................10 Social differences in nutritional habits of Lithuanian population …………14 Discussion …………………………………………………………………….21 Acknowledgment …………………………………………………………… 31 References ……………………………………………………………………32 List of abbreviation ………………………………………………………….42  INTRODUCTION Food and health are highly associated. Food can offer health and life but it can also bring illness and death. Diet plays an important role in most of the chronic noncomunicable diseases (NCD): cardiovascular diseases, hypertension and stroke, obesity, type II diabetes mellitus, various forms of cancers (1). As a result of industrialization, urbanization, economic development, and market globalization rapid changes in diets and lifestyles have taken place over the last decades; these changes are making a significant impact upon the health and nutritional status of populations. The transition in nutrition is marked by a transformation from diets based on staple foods, such as grains, potatoes, locally grown vegetables, towards more varied diets that include more processed food, more foods of animal origin, and more added sugar, salt and fat (2, 3). Dietary changes together with reduced physical activity have been leading to a rapid increase in NCD. In 2001, chronic diseases contributed approximately 60% of the total reported deaths in the world and approximately 46% of the global burden of disease (4). During the last decade dramatic changes occurred in the political, social and economic situation of Lithuania. These changes have affected health and diet habits of the population: during the transition towards the market economy, the availability of certain foods have been reduced for some population subgroups, the reductions in subsidies have increased the prices of food products, and market globalization as well as insistent advertisement has decreased the demand for local traditional foods. On the other hand, the availability of healthy foods such as vegetable oil, margarine, or skimmed milk increased. During the transition period in the 1990’s, people from low socioeconomic groups appeared to be the most affected by the economical instability. Studies that were carried out in Lithuania have shown higher mortality in lower socioeconomic groups (5). Trends in mortality were not steady throughout the period of 1991-2000. An average increase in mortality within Lithuanian population during the period of 1991-1994 had reached 4.1% per year. In 1995-2000, a decreasing tendency was observed. Positive changes were determined by mortality from cardiovascular disease (about 50%) (6). Increasing inequalities in mortality by education, occupation, place of residence were documented (7-12). The risk of death from cardiovascular disease was 1.5 times higher among manual workers than among non-manual workers (13). Usually non-manual workers have a higher level of education. Studies that have been carried out in Lithuania on the inequalities in health present a significantly lower mortality of people with higher education compared to those with no higher education (14, 15). Life expectancy in men with incomplete secondary education was 11.7 years shorter, and the life expectancy in women with incomplete secondary education was 4.3 years shorter, as compared to better-educated men and women (16). During the periods of political and economical transition, less educated people tend to be at the worse situation when competing for a better-paid job, pursued occupation, favourable working conditions. On the other hand, the mortality of the rural population is significantly higher than the mortality of people living in the urban areas, and these 2  inequalities are increasing (7). Trends in life expectancy differ markedly among the urban and rural population. It is well documented that health inequalities depend on economic, cultural, psychosocial, environmental and lifestyle factors, where nutrition also plays a significant role (17, 18). Dietary survey data indicate that unfavourable dietary habits might explain part of the socioeconomic disparities in health (18). People with a higher socioeconomic status have a healthier diet compared to those with lower socioeconomic status (19-23). Higher socioeconomic status is associated with higher consumption of both fruit and vegetable and lower consumption of animal fat. People from higher social classes are more likely to choose modern and healthy foods, while people with lower socioeconomic status tend to follow a traditional diet (2, 24-26). Those belonging to a lower social class are exposed to an unhealthier environment; they have a lower income, and may not be able to afford to buy the more expensive, healthy food (19, 27, 28). People with lower socioeconomic status usually have less money to spend on food. Probably they have a lower income as they are more likely to be unemployed, receiving benefits and less qualified. The most common socioeconomic status indicators employed in the studies are education, occupation and income (29). Education has some advantages compared to occupation and income, because it is easy to measure and it sustains minor changes over adult life. Therefore, education is frequently taken to be the main measure of the socioeconomic status. The data of the surveys performed in 15 European countries have shown a relationship between the education and the consumption of vegetables and fruits: in many countries a higher education level was associated with a greater consumption of fruits and vegetables (18, 30). A positive correlation between education level and consumption of fruits and vegetables was stronger in the Nordic countries as compared with the South European countries (31). However, the results of a recent study have indicated that Spanish people with university education consumed fruit and vegetables more frequently than those with low education did (32). Other investigators have confirmed that low and high- educated people had different sources of fats. For example, high-educated Finns consumed less whole milk and butter on bread but they eat more cheese than the low educated people did (3). As a result, the proportion of fat in food was similar among all educational groups. Well-educated people may more easily understand the advantages of a healthy diet (3, 16, 33). 85% of highly educated Norwegian women and 61% of men preferred food they considered to be healthy (31). The survey that had been carried out in England suggested that social class and education were making impact upon the ways people learned how to cook. Cookery books were more important for higher social classes, whilst cookery classes at school were more important for lower social classes. Socioeconomic status is a very important social determinant in public health nutrition studies. However, the use of other social determinants such as gender, place of residence, and family status is none the less significant, too. Gender is related to certain 3  roles and statuses in the society and family (27). Men and women have different perspectives and priorities in relation to such issues as diet and health, and even the ethical dimension of food choice (34, 35). A food choice is a way to express social position as well as masculinity or femininity. Men have traditionally valued heavy, powerful, and strong things, while women put the emphasis on lightness (27). By choosing red meat, men show their virility and power. A significant greater proportion of the energy consumed by men in a range of Europe societies is obtained from meat, animal products and alcohol, while that of women is obtained from vegetable, fruits and berries (36-38). It is more uncertain however, which status is ascribed to fish. Bourdieu finds that especially in the working classes of France, fish seems to be regarded as an unsuitable food for men (39). Nevertheless, it has been found in other studies that fish goes well with male identity, especially in fishing communities (40 ). Man and women tend to hold rather different views on what is the ideal body shape for each sex. Men and women tend to display similar rates of obesity. However, women seem to be more inclined to lose weight thought food intake restriction as well as to be more dissatisfied with their body shape if compared to men (41). In the UK study 40,8% of women and only 23.9% of men pointed out that they were dissatisfied with their body shape (34). Guilt in relation to eating also seemed to be frequently prevalent in females than in males. Lean constitution is a desirable body shape for women, while well-toned, muscular body is a typical value for men. Theses stereotypes may vary according to different counties and cultures. But it may be that the western cultural force to keep the thin female body more compulsory as compared with ‘good’ male body images (42). According to many international studies, women have healthier food behavior and diets more consistent with current nutrient recommendations if compared to men (43-45). Population dietary changes among women are observed earlier and more pronounced if compared to the behaviour of men. This includes an increase in vegetable consumption, a decrease in meat consumption, and a switch from fat to leaner milk types (31, 46). In most Western countries men drink more alcohol and eat more meat and potatoes (and less fish, chicken, vegetables, fruits and cheese) than women (44, 45). Dietary surveys in Denmark have documented that meat, potatoes, and alcohol make up a relatively greater proportion of men’s diets if compared to the proportion of these consumed by women, while vegetables, fruits, fish, cottage cheese, yoghurt compose a greater proportion of women’s diet (47). Similar data were reported in a number of dietary surveys undertaken in Finland, Sweden, Great Britain, Norway (48-51). Women seem to be more knowledgeable about food and nutrition and indicate higher levels of care in selecting foods to achieve a healthy diet (52-54). Women more often than men chose the foods they considered to be healthy. Men frequently prefer food they like (55-57). There was a huge gender difference in the frequency of meal cooking. A total of 68% of women indicated that they cooked every day, compared to only 18% of men (58). Food purchasing and preparation is most often a women responsibility; women might be influencing the amount eaten at each meal, as well as the frequency of such meal, or food products eaten. Dietary habits vary with age. Some of the previous studies have demonstrated that diet of older people is healthier if compared to the diet of the young (59, 60). A cross- 4  sectional study that was carried out in England showed that 16-24 year old people were classified as low consumers, compared with only 36% of 45-74 year olds (50). A higher consumption of fruit and vegetables was also reported by the older respondents (49, 59, 61). In addition, the Malmo Diet and Cancer Study has revealed that the proportion of people reporting low consumption of vegetables and no consumption of fruit juices increased with age, while the proportion with a low consumption of fruits decreased with increasing age (51). However, the results of the France survey stated that the lower intake of fruit and vegetables for young people is a generation effect and not an age effect (62). The finding being explained by the fact that the younger generation is not interested in preparing fresh vegetables and fruit. The fruit and vegetables that are eaten more frequently by the young are the ones that are convenient to eat (tomatoes, mandarins, bananas), while those that are eaten less frequently are less convenient and require some preparation (cauliflowers, leeks, lettuces) (62). Full fat milk was often used as drinking milk, however, significantly frequently in the oldest age group (59). In the Baltic countries, the corresponding data were revealed (52). According Australian studies, reduced fat milk consumption was more frequent among the elderly people and women (63). Most aged men and women more often preferred butter to margarine as a spread on bread if compared to the youngest people (52, 53, 59, 64). Danish studies have indicated, that older man and women consumed animal fats, low-fat margarine, light rye bread, white bread, potatoes, fruit, fish and jam more frequently, and vegetable margarine, milk, coarse rye bread, coarse white bread, rice, pasta, meat for sandwiches, ice cream and candies less frequently if compared to the younger age groups (46). The data from the English Cohort-EPIC study have demonstrated that the age trends represent the differences of at least 20% between the youngest and the oldest population for white fish, soup, and tea (that were consumed more by older respondents. At the same time alcohol, other drinks, legumes, nuts, other cereal products, fish products, coffee, vegetarian foods, poultry, and shellfish were all consumed more frequently by the younger subjects (65). Generally, fruit, vegetables, and other high-fibre foods were more popular among the middle-aged, whereas soft drinks, salty snacks, high-fat foods were more popular among the younger persons (48, 59). Urban Norwegian men, as well as women reported a higher consumption of fruit and vegetables in comparison to those living in rural areas. Diet of men living in cities had lower proportion of energy from fat than men living in rural areas (26). The relationship between the place of residence and the usage of fats and fruit were revealed in a Chinese study. The Chinese people that lived in cities consumed fat, animal products and fruit more frequently (66). The analogous situation is observed with different developing countries, reflecting the rate of economic development as well as demonstrating that higher socioeconomic groups can afford more luxurious food products (66). Many studies have investigated the differences in nutritional habits according to the family status (3, 67-71). Marital status and health behaviour have significantly been related in most cases. The married ones had better diet if compared to the unmarried ones (43, 72). Finish men in favour of healthy diets were most often married. They reported a low consumption of meat and white bread, a high consumption of fish and whole meal bread, a low consumption of full cream milk, cream, butter, sugar, biscuits and pies, a moderate consumption of wine and low consumption of beer, a high 5  consumption of fruit and vegetables (73). Nevertheless, the data from the East Anglia presented contrary results. In health and nutrition studies, the strength of the association between health, nutrition and marital status has been found to be different for men and women. Women were more likely to control the health of the rest of the family members through the food served in the family (27, 69). Women were usually responsible for the food preparation, even if they worked longer hours than husbands did (69, 74). Less than 40% of men with wives employed full-time and less than 30% of husbands with wives employed part-time or not employed at all shared in meal preparation (75). Several more studies have demonstrated that marriage often has a positive impact on nutritional behavior, particularly for mans and suggest that women appear to make a positive impact upon the quality of their husbands’ diets, while men have little or no impact on the quality of their wives’ diets (67). Since eating behaviour is for the most part a learned behaviour, parents, and especially mothers, play an important role in children nutrition (19, 43). Scientific literature presents that mothers from a higher social class more frequently assume that children’s taste could be developed, whereas working class mothers more frequently consider that children might eat snacks as long as they are provided with three main meals per day, as well as that tasty food is important to please children and family (43). Despite a tighter budge, lower social class mothers bought foodstuffs, which their family preferred, more frequently if compared to higher or middle class mothers (19). AIM The aim of the study is to assess the socio-demographic variations in nutritional habits and their trends over the last decade in Lithuanian adult population. SPECIFIC OBJECTIVES To evaluate the trends in food habits of Lithuanian adult population between 1994 and 2004. To determine gender and age differences in nutritional habits in Lithuanian adult population; To examine the associations between nutritional habits and the level of education; To evaluate the differences in nutritional habits in relation to the place of residence and marital status. 6  MATERIAL AND METHODS Lithuania joined the international project of health behaviour monitoring (FINBALT HEALTH MONITOR) in 1994. Finland, Estonia, Latvia, and Lithuania are the countries participating in this project. In Lithuania, six health behaviour surveys on national samples of the adult population were being carried out every two years. For every survey, a national random sample of 3000 inhabitants (aged 20-64) was taken from the National Population Register. The sampling unit was individual in all the surveys and no measures to substitute for non- respondents were taken. The study material was collected through a postal survey. The questionnaires were mailed in March and those who did not respond within a month received another copy of the questionnaire in May. The self-administrated questionnaire was filled-in by 11659 respondents (5146 men and 6513 women) altogether. Table 1 presents the number of the respondents of each survey. Response rates ranged from 61.7% to 74.4% (Table 1). Table 1. Number of respondents and response rate Number of respondents Men Women Total Response rate Year N % N % N % % 1994 787 42.2 1077 57.8 1864 100 64.3 1996 920 45.5 1101 54.5 2021 100 68.9 1998 823 43.9 1051 56.1 1874 100 63.8 2000 996 45.4 1199 54.6 2195 100 74.4 2002 836 44.4 1047 55.6 1883 100 63.6 2004 784 43.0 1037 57.0 1822 100 61.7 Total 5146 44.1 6513 55.9 11659 100 The standardized questionnaire contained questions on the socio-demographic characteristics, subjective health, smoking, nutrition habits, alcohol consumption, physical activity, and advice to change health behaviour. The main questions of interest have been kept unchanged to ensure the comparability between the years studied. The respondents were differentiated into three age groups: 20-34, 35-49, and 50-64 year-old. Education was measured using five educational levels (primary, incomplete secondary, secondary, vocational, and university). The respondents were categorized into three main groups: persons with incomplete secondary education (primary or incomplete secondary), secondary (secondary or vocational), and university education. The degree of urbanization was based on the administrative classification of the places of residence. The respondents were grouped as living in cities, towns, or villages according to their place of residence. They were categorized as married and unmarried according to their marital status. 7  In 1994, the questionnaire included 13 separate food-related questions dealing with cooking fats, bread spreads, vegetables, milk, bread, eggs, sugar, coffee and tea consumption. Since 1996 the question on the frequency of the consumption of fresh vegetables has been included and since 1998, the food frequency questionnaire (FFQ) has been included. The respondent was asked to mark the frequency of the consumption of the 20 common food items: ‘How often during the last week have you consumed the following foods and drinks?’ The respondent could choose one of the following answers: never, 1-2 days a week, 3-5 days a week, or 6-7 days a week. What concerns the food items, the former questions on cooking fats, bread spreads, milk, bread, eggs, sugar, and coffee and tea consumption were kept unchanged. Statistical analysis Statistical analyses were performed using the statistical software package SPSS 11.0 for Windows. In order to assess the trends in nutrition habits between 1994 and 2004, age- adjusted prevalence rates were calculated using the distribution of Lithuanian population by age in 2001 (census data) as a standard. P for the trends was estimated. Data from 1998, 2000, 2002, and 2004 were used for the analysis of the associations between the social factors and nutrition habits. The differences in the distribution of the respondents were assessed using analyses of the chi-squared tests. The difference was considered to be significant when p<0.05. The effect of age, level of education, place of residence, and marital status upon nutritional habits was evaluated using multifactor logistic regression analysis that was carried out separately for men and women The reference groups were as follows: the age group of 20-34 year-olds, the respondents with an incomplete secondary education, the residents of the urban areas, and the married subjects. The results are presented as odds ratios and 95% confidence intervals. When the 95% confidence interval did not include 1, the odds ratio was considered to be statistically significant. The scientific literature survey on the investigated subject was done using the Pub Med database. References were listed according to the Vancouver citation system. 8  RESULTS The trends in the nutritional habits of the Lithuanian population in 1994-2004 Substantial changes in nutritional habits of the Lithuanian population over the last ten years have been observed (Fig.1). Since 1994, the proportion of persons using mostly vegetable oil for cooking has doubled (among men from 31.1% in 1994 to 82.6% in 2004, and among women - from 47.7% to 89.4%, respectively). The data of the last survey showed that only 8.5% of men and 5.6% of women used lard for cooking. Men 10 20 30 40 50 60 70 80 90 1994 1996 1998 2000 2002 2004 Oil for cooking Butter on bread Women 10 20 30 40 50 60 70 80 90 1994 1996 1998 2000 2002 2004 Fresh vegetables Whole milk Fig.1. Trends in the nutritional habits of the Lithuanian adult population in 1994-2004 (the proportion of persons using vegetable oil for cooking, spreading butter on bread, drinking high-fat milk and eating fresh vegetables at least 3 days a week; p for trends < 0.05 for all nutritional habits in men and women) The usage of vegetable oil has increased in all educational groups of population, and that increase was most substantial among people with lower education. Although the educational differences in the usage of vegetable oil were diminishing over ten years, in 2004 people with university education continued to use vegetable oil more often compared to those with incomplete secondary education (Fig.2). The data of the last 9  survey showed that the use of vegetable oil was more common in urban than in rural areas. However, the increase was more evident in rural areas (Fig.3). 17 78* 43 88* 25 75* 62 92* 0 10 20 30 40 50 60 70 80 90 100 % Incomplete secondary education University Incomplete secondary education University 1994 2004 Men Women *p<0.05 compared to 1994 Fig.2. Proportion of persons using vegetable oil for cooking in 1994 and 2004 by level of education Men Women *p<0.05 compared to 1994 Fig.3. Proportion of persons using vegetable oil for cooking in 1994 and 2004 by place of residence 1 75 4 88 2 83 6 94 0 10 20 30 40 50 60 70 80 90 100 % 1994 2004 Rural Urban Rural Urban 10  In 1994, 74.2% of men and 66.3% of women indicated that they had used butter on bread (Fig.1). In the year 2000, the proportion of persons who spread butter on bread halved (in men - from 71.2% in 1994 to 37.6% in 2000, and in women - from 66.3% to 38.2%, respectively) because people started to use margarine. However, data of 2002 and 2004 showed that the use of butter increased again. Over the last five years, the availability of spreads based on milk fats (mixture of butter and vegetable oil) has increased in the Lithuanian market significantly, and people started to consume them, which resulted in the increase in the use of animal fat on bread. In 2004, 52% of men and 53.8% of women reported that they used butter or mixture of butter on bread. People with incomplete secondary education have decreased the usage of butter on bread, while frequency of this habit has not changed among better educated people (Fig.4). The proportion of persons that started to spread margarine instead of butter on bread was larger in rural than in urban areas. In 2004, spreading of butter on bread was less common among women living in rural areas than among women in cities (Fig.5). 76 50* 65 61 61 43* 61 57 0 90 80 70 60 50 % 40 1994 30 2004 20 10 Incomplete seconday education University Incomplete seconday education University Over the ten-year period, almost no changes have been found in the consumption of high-fat milk (Fig.1). In 2004, 37.8% of the respondents reported drinking this kind of milk, while in 1994 this habit was indicated by 46.8% of the subjects. Men Women *p<0.05 compared to 1994 . Proportion of persons spreading butter on bread in 1994 and 2004 by level Fig.4 of education Over the ten-year period, almost no changes have been found in the consumption of high-fat milk (Fig.1). In 2004, 37.8% of the respondents reported drinking this kind of milk, while in 1994 this habit was indicated by 46.8% of the subjects. 11  72 50* 69 54* 68 47* 64 58 0 1 0 2 0 3 0 4 0 5 0 6 0 % 7 0 8 0 R ural U rban R ural U rban 1 9 9 4 2 0 0 4 Men Women *p<0.05 compared to 1994 Fig.5. Proportion of persons spreading butter on bread in 1994 and 2004 by place of residence Lithuanians started to eat fresh vegetables more frequently. In 1996, 18.1% of men and 24.8% of women consumed fresh vegetables at least three days during the last week, while in the year 2004 this proportion was 39.9% in men and 49.9% in women (Fig.1). In the last survey, daily consumption of fresh vegetables was reported by 14.9% of men and by 18.7% of women (in 1996 – by 3.5% and 5.4%, respectively). The frequency of the consumption of fresh vegetables has increased in all educational groups. However, the differences between the groups remained (Fig.6). The respondents with university education more frequently ate fresh vegetables than those with incomplete secondary education. The increase in the consumption of fresh vegetables was more evident in urban than in rural population (Fig.7) Over the period of ten years, the consumption of fresh fruit and berries has almost not changed. In 2004, 25.8% of men and 40.2% of women at least three days a week ate fresh fruit and berries. 14 28* 24 43* 14 33* 38 54* 0 1 0 2 0 3 0 4 0 5 0 6 0 % Inc om ple te s e condary educ ation Unive rs ity Inc om ple te s e condary educ ation Unive rs ity 1 9 9 6 2 0 0 4 Men Women *p<0.05 compared to 1996 Fig.6. Proportion of persons who have eaten fresh vegetables at least 3 days during the last week in 1996 and 2004 by level of education 12