Lars Johansson

Healthy dietary habits in relation to social determinants and lifestyle factors

The aim of the present study was to evaluate the importance of social status and lifestyle for dietary habits, since these factors may influence life expectancy. We studied the association of four indicators for healthy dietary habits (fruits and vegetables, fibre, fat and Hegsted score) with sex, age, socio-economic status, education, physical leisure exercise, smoking and personal attention paid to keeping a healthy diet. Data were gathered with a self-administered quantitative food-frequency questionnaire distributed to a representative sample of Norwegian men and women aged 16-79 years in a national dietary survey, of whom 3144 subjects (63%) responded. Age and female sex were positively associated with indicators for healthy dietary habits. By separate evaluation length of education, regular physical leisure exercise and degree of attention paid to keeping a healthy diet were positively associated with all four indicators for healthy dietary habits in both sexes. Socio-economic status, location of residence and smoking habits were associated with from one to three indicators for healthy dietary habits. In a multiple regression model, age, education and location of residence together explained from 1 to 9% of the variation (R2) in the four dietary indicators. Length of education was significantly associated with three of four dietary indicators both among men and women. By including the variable attention paid to keeping a healthy diet in the model, R2 increased to between 4 and 15% for the four dietary indicators. Length of education remained correlated to three dietary indicators among women, and one indicator among men, after adjusting for attention to healthy diet, age and location of residence. Residence in cities remained correlated to two indicators among men, but none among women, after adjusting for age, education and attention to healthy diet. In conclusion, education was associated with indicators of a healthy diet. Attention to healthy diet showed the strongest and most consistent association with all four indicators for healthy dietary habits in both sexes. This suggests that personal preferences may be just as important for having a healthy diet as social status determinants.

Disparities in vegetable and fruit consumption: European cases from the north to the south.

OBJECTIVEnTo present disparities in consumption of vegetables and fruits in Europe and to discuss how educational level, region and level of consumption influence the variation.nnnDESIGNnA review of selected studies from 1985 to 1997.nnnSETTING/SUBJECTSn33 studies (13 dietary surveys, nine household budget surveys and 11 health behaviour surveys) representing 15 European countries were selected based on criteria developed as part of the study. Association between educational level and consumption of vegetables and fruits was registered for each study and common conclusions were identified.nnnRESULTSnIn the majority of the studies, with the exception of a few in southern and eastern Europe, consumption of vegetables and fruits was more common among those with higher education. The results suggest that in regions where consumption of vegetables and fruits is more common, the lower social classes tend to consume more of these than the higher social classes.nnnCONCLUSIONSnThe differences in the patterns of disparities in vegetable and fruit consumption between regions, as well as within populations, need to be considered when efforts to improve nutrition and health are planned.

The iodine content of Norwegian foods and diets

OBJECTIVESnTo examine dietary iodine sources and to estimate the dietary iodine intake of the Norwegian population.nnnDESIGNnFood iodine analyses carried out in Norway during the last 10 years were compiled, and iodine intake calculated on the basis of food intake data from nation-wide dietary surveys among children and adults. The food intake of adults was measured by a self-administrated food-frequency questionnaire, which covered habitual diet during the past year. The food intake of children was measured by dietary record during four consecutive days.nnnSETTINGnNeither household nor industrial iodisation of salt is mandatory in Norway, but some brands of table salt have 5 microg of iodine added per gram of NaCl. In spite of this, the population has been considered iodine-replete for decades, i.e. having an iodine intake well above the Recommended Dietary Allowance of 150 microg day(-1). This assumption has not been substantiated by dietary surveys.nnnSUBJECTSnThe adults included 1374 females and 1298 males aged 16-79 years. The children included 185 girls and 206 boys aged 4 years, 411 girls and 404 boys aged 9 years, and 517 girls and 492 boys aged 13 years.nnnRESULTSnThe calculated iodine intake was in the range of 100-250 microg day(-1) in the majority of the adult population. The mean iodine intake was 136 microg day(-1) (170 microg I/10 MJ) among women and 176 microg day(-1) (161 microg I/10 MJ) among men. For children the iodine intake was in the range of 100-120 microg day(-1). Milk and dairy products contributed approximately 55% and 70% of the dietary iodine intake in adults and children, respectively. Fish contributed more than 20% of the iodine intake in adults and about 10% in children. The iodine contribution of drinking water was negligible.nnnCONCLUSIONSnWhile fish has the highest natural concentration of iodine and as such is an excellent iodine source, milk and diary products are the main determinants of iodine intake in the Norwegian population. Iodisation of cow fodder has been mandatory in Norway since 1950 and provides an efficient alternative to universal salt iodisation. Our results show that the dietary iodine intake of adults is in the range considered to be sufficient. The dietary intake of iodine was at recommended levels among the youngest children; however, it decreased among adolescents, especially among girls.

Intake of very-long-chain n-3 fatty acids related to social status and lifestyle.

Objectives: Little information is available about the intake of very-long-chain n-3 fatty acids in random samples of populations. We examined if the intake of these fatty acids was associated with gender, social status and lifestyle in a similar way as other indicators for a healthy diet in a nationwide survey.Design and subjects: Data were obtained from self-administered quantitative food frequency questionnaires filled in by a representative sample of Norwegian men and women, aged 16–79u2005y. 3144 (63%) of the invited subjects responded with acceptable questionnaires.Results: Daily intake of very-long-chain n-3 fatty acids was on average 0.9u2005g/d and 0.4% of total energy was derived from these fatty acids. Energy derived from very-long-chain n-3 fatty acids was slightly higher among men than women, and two-fold higher among subjects aged 60–79 vs 16–29u2005y. White collar workers had higher intake of very-long-chain n-3 fatty acids than blue collar workers. Men and women in the highest quartile of intake of very-long-chain n-3 fatty acids had 2–3u2005E% higher fat intake (mostly mono- and polyunsaturated fatty acids), as compared to individuals in the lowest quartile. They also had 3–4 fold higher daily intake of retinol and vitamin D, as well as 20–50% higher intake of fruits and vegetables, dietary fibre and vitamin C.Conclusions: Intake of very-long-chain n-3 fatty acids was correlated to indicators for healthy dietary habits. However, contrary to many other indicators of a healthy diet, energy derived from very-long-chain n-3 fatty acids was not significantly associated with female gender or non-smoking.Sponsorship: Ministry for Health and Social Affairs, Ministry for Agriculture and Norwegian Research Council.

Evaluation of three dietary assessment methods and serum biomarkers as measures of fruit and vegetable intake, using the method of triads

The validity of fruit and vegetable intake estimated by 14 d weighed records, a twenty-seven-item food frequency questionnaire (FFQ) and a 180-item FFQ was investigated using serum carotenoids as the validity criterion. In addition, the method of triads was used to assess the validity of fruit and vegetable intake estimated from the FFQ and serum carotenoids. One hundred Norwegian men completed 14 d weighed records and the 180-item FFQ. Eighty-six of them also completed the twenty-seven item FFQ. The partial correlation coefficients between serum carotenoids and fruit and vegetable intake were slightly higher for the 14 d weighed records than for the two FFQ, but no difference was observed between the 180- and the twenty-seven item FFQ. The strongest correlations were observed between vegetable intake and serum alpha-carotene. The highest validity coefficients (VC) were observed for vegetable intake estimated from weighed records, the 180-item FFQ, the twenty-seven item FFQ and by the biomarker serum alpha-carotene, with VC of 0.77, 0.58, 0.51 and 0.67, respectively. In conclusion, the short FFQ gave as valid estimates for fruit and vegetable intake as the long FFQ. Both the estimated partial correlation coefficients and VC suggest that serum alpha-carotene is the best biomarker for intake of vegetable alone and total intake of fruit and vegetables in this population of Norwegian men, but the biomarkers did not perform any better than the FFQ.

Response rates with different distribution methods and reward, and reproducibility of a quantitative food frequency questionnaire

Objectives: To evaluate the use of a self-administered quantitative food frequency questionnaire (QFFQ) in a national dietary survey concerning (a) response rates with different distribution methods and reward; (b) degree of underreporting of energy intake; (c) reproducibility of the QFFQ; and (d) seasonal variation on reported intake. Design and subjects: A pilot study was performed in 1992 to test response rates to the QFFQ with three different distribution methods, with and without reward, in a random sample of 1200 adults aged 16–79u2005y. In another study, the QFFQ was distributed to a nation-wide, representative random sample of 5008 adults aged 16–79u2005y during June, September, November 1993 and March 1994. Reproducibility was evaluated among 90 responders to the survey who answered another QFFQ six weeks later. Results: The distribution method combining postal distribution and collecting the QFFQ by interviewer as well as an offer to participate in a lottery, gave the highest response rate (72%). The possibility to get a reward increased the response rate by 9, 14 and 57%, respectively, depending on the distribution method used. The mean daily energy intake and the percentage of subjects claiming to have unlikely low energy intake did not differ significantly between the different ways of distribution. In the main survey the mean ratio between energy intake and estimated basal metabolic rate was 1.58 among men and 1.47 among women, and 37% of men and 45% of women had a ratio below 1.35. Spearman rank correlations between the two QFFQ ranged from 0.48 (edible fats) to 0.91 (coffee) with a median coefficient of 0.70. For nutrients correlations ranged from 0.55 (carbohydrate E%) to 0.81 (alcohol), with a median coefficient of 0.72. The season of questionnaire administration was of minor importance for the reported intake of the main foods and nutrients. Conclusions: The QFFQ-method is suitable for use in a Norwegian nutritional surveillance system. Sponsorship: National Nutrition Council, Ministry for Agriculture, Ministry for Health and Social Affairs and Norwegian Research Council.

Breast-feeding at 12 months of age and dietary habits among breast-fed and non-breast-fed infants

OBJECTIVEnTo analyse factors associated with breast-feeding and use of sweetened drinks at 12 months, and to compare dietary habits among breast-fed and non-breast-fed infants.nnnDESIGNnData were collected by a semi-quantitative food-frequency questionnaire filled in by the parents.nnnSETTINGnNational dietary survey in Norway.nnnSUBJECTSnIn total, 1932 12-month-old infants were included.nnnRESULTSnAt 12 months, 36% of the infants were breast-fed. The odds of breast-feeding at this age were more than doubled both for mothers > or =35 years compared with mothers <25 years and for mothers in the highest educational group compared with mothers in the lowest. A negative association was found for maternal smoking, and the odds of breast-feeding were 40% lower for mothers who smoked than for non-smokers. Some dietary differences were observed between breast-fed and non-breast-fed infants apart from intake of milk. In particular, breast-fed infants had a significantly lower daily intake of sweetened drinks than non-breast-fed infants and a 16% lower mean daily intake of added sugars (P<0.001). Furthermore, breast-fed infants had 30% higher odds of not receiving sweetened drinks daily, compared with non-breast-fed infants.nnnCONCLUSIONSnMaternal age, education and smoking status were important factors for breast-feeding at 12 months. Breast-fed infants had lower intakes of sweetened drinks and added sugars than non-breast-fed infants. From a public health perspective, continued promotion of breast-feeding is needed to reduce inequalities in breast-feeding. Moreover, prevention of high intakes of sweetened drinks and added sugars should start in infancy.

Relations between high ponderal index at birth, feeding practices and body mass index in infancy.

Objective:We compared feeding practices between infants of high ponderal index (PI) at birth (PI above the 90th percentile) and normal PI at birth (PI between 10th and 90th percentiles), and examined how birth size and infant feeding practices were related to body mass index (BMI) at 12 months.Design:In a cohort of 3000 infants invited to participate in a national Norwegian dietary survey, 1825 participated both at 6 and 12 months of age, and the present study included those born full term and with a PI (weight/length3) at birth ≥10th percentile (n=1441). Data on feeding practices were collected by food-frequency questionnaires, and anthropometrical data were measured by health-care personnel.Results:A lower proportion of infants born with high PI were exclusively breastfed for at least 4 months compared with infants born with normal PI (37 and 47%, respectively; P=0.03). Earlier introduction of solid foods and higher consumption of some foods were also observed among infants of high PI. In a multivariate analysis, adjusted mean BMI (kg/m2) at 12 months was higher for infants of high PI at birth than for infants of normal PI (17.6 and 17.0, respectively; P<0.001) and higher for infants exclusively breastfed <3 months than for infants exclusively breastfed ≥3 months (17.5 and 17.2, respectively; P=0.001).Conclusions:High PI at birth was associated with a shorter duration of exclusive breastfeeding. Furthermore, high PI at birth and short-term exclusive breastfeeding were both associated with higher BMI at 12 months.Sponsorship:The National Council on Nutrition and Physical Activity (now part of the Directorate for Health and Social Affairs), the Norwegian Food Control Authorities (now part of the Norwegian Food Safety Authority) and the Research Council of Norway.

Nutrition and Food Policy in Norway

Key Points n nThe Norwegian Nutrition and Food Policy has its roots in the 1930s. A National Nutrition Council (NNC) was established in 1937 and re-organized in1946. Since then, it has had a mandate to give advice to the government regarding nutrition. n n nAfter 1950, there was a substantial increase in mortality from coronary heart diseases (CHDs) that was associated with changes in food habits and lifestyle. In 1963, this increase resulted in an official Norwegian report on the relationship between dietary fat and cardiovascular disease. The report formed a basis for subsequent work, with the formulation of an official integrated Norwegian Nutrition and Food Policy. n n nA White Paper was presented to the Storting (Norwegian Parliament) through Report No. 32 (1975–1976) “On Norwegian Nutrition and Food Policy.” In 1981, the government presented a follow-up White Paper. Later, the Nutrition and Food Policy was integrated into the health policy in reports to the Storting in 1993 and 2003. n n nThese four White Papers define the nutritional goals to be achieved for Norway and the measures that the government intends to employ to improve the Norwegian diet. n n nThe most recent White Paper advocated a broad health policy. It drew attention to the connections between the individual’s and the community’s responsibility for and possibility of influencing the health situation. At the ministerial level, two official bodies are given the responsibility to coordinate the implementation of the Nutrition and Food Policy: the National Food Control Authority and the NNC. n n nThe official nutrition and food policy White Papers have been central political and strategic documents in the efforts to improve public health in Norway during the last 30 yr. Currently, we can see several changes in Norwegian eating habits. Fat consumption has decreased from 40 to 34% of the food energy, mainly by a reduction of saturated and trans fat. Concomitantly, blood cholesterol has decreased, and mortality from CHD among middle-aged individuals has decreased by 60% during the last 30 yr. n n nHowever, the prevalence of cancer, obesity, and type 2 diabetes has increased in the Norwegian population. The most recent White Paper was seriously concerned with these problems and provided suggestions and measures both for the society and the individual for improving the diet and increasing physical activity in daily life during the whole lifetime.