JOURNAL OF THE SCIENTIFIC AGRICULTURAL SOCIETY OF FINLAND 448 Maataloustieteellinen A ikakauskirja Vol. 49:448- 455, 1977 Nutrition survey of Finnish rural children V. Seasonal differences in food consumption and nutrient intakes Leena Räsänen and Johanna Niinikangas University of Helsinki, Department of Nutrition 00710 Helsinki 71 , Finland Abstract. In connection with a survey of child nutrition in Finland the food consump- tion and nutrient intakes of the children in summer and in winter were compared. The material consisted of 158 children aged 5, 9 and 13 years living in Nurmijärvi. Food consumption was measured by the 24-hour recall method and the nutrient intakes were calculated on the basis of food composition tables. The interviews were made in June and the following January and February. The diet in winter included significantly more fruits and berries, inner organs and blood but less vegetables and milk products other than milk, sour milk or cheese. The differences were the same in all age groups. The intakes of energy and nutrients were notably similar in summer and in winter. Only the intakes of iron, vitamin A and ascorbic acid were higher in winter than in summer. This can be ascribed to the high consumption of inner organs and blood. The large consumption of fruits, citrus fruits in particular, raised the ascorbic acid intake to a quite high level in winter. The differences in the present study between the diets of the children in summer and winter were not similar to those observed earlier among Finnish adults. The increased use of imported foodstuffs and the development of the domestic food industry have obviously levelled off the sharp seasonal fluctuations earlier seen in the Finnish diet. Introduction The composition of the Finnish diet is characterized by seasonal fluctua- tions due mainly to the effects of the climate on food production and con- sequently on the availability of various food supplies. However, import of foodstuffs has always increased the variety of food supplies available to the consumer, and is gradually becoming more important. In a number of dietary surveys the consumption of vegetables, berries and fruits has been found to be highest in autumn and lowest in late spring and early summer (Virtanen and Turpeinen 1940, Roine 1954, Konttinen and Roine 1962, Pekkarinen and Roine 1964). According to the same surveys meat consumption was generally greater in autumn and winter than in other seasons of the year, while fish was https://www.c-info.fi/en/info/?token=9bV98qb5A-sFR747.hjXMVl8vFgwS9-VP9z8zPw.rO27AmSosmK16mqBzTquAPRfiQZRw1GkBJriMZOwnBuADUSu006PCdsv55jf1lpOuicxnxx2Rxm_XY57iUno4uuPxem_z_Yl7TuUrnuleAbfQQaAIiQP1qX0r8dlKwqPMJtoNcmkgr0ciWUEmh-XvDSHlxg14JFxNfegE1tqx1jhVS4gWZDBVsrjIRBXzqXhYlfw0uEpMQpwbPj0Ew 449 used most abundantly in spring and summer. These fluctuations in food consumption were reflected in the intakes of nutrients, most clearly in those of vitamin A and ascorbic acid, the intakes of which were highest in autumn and lowest in spring and early summer. The survey of nutrition of Finnish children (Räsänen et ai. 1975, Räsänen and Ahlström 1975) included a study aimed at clarifying whether there are significant differences in the food consumption and nutrient intakes of the children in summer and winter and if so, what such seasonal fluctuations are. Material The nutrition survey made in the rural commune of Nurmijärvi was attended by 208 children 5, 9 and 13 years of age. A 24-hour recall of food consumption was obtained from 198 of these children in summer 1971 (June 3—12). In two cases interviews were not obtained at all and eight interviews were discarded as incomplete or obviously unreliable. In this first stage of the survey the children and their parents were asked if they were willing to attend a follow-up interview to be possibly made in the following winter. An absolute refusal was received from 11 subjects, who therefore were not contacted later. Three children did not attend because of change of residence, and 21 children did not respond to the written invitation. A total of 163 children attended the survey made in winter 1972 (January 10 February 10). In two cases interviews were not obtained and three interviews were discarded as incomplete or unreliable. The material of the present study therefore consists of 158 children from whom a 24-hour recall was obtained in both summer and winter. 55 of the children were 5 years, 59 9 years and 44 13 years old. Methods Food concumption was assessed by the 24-hour recall method, and from this information energy and nutrient intakes were calculated using the Finnish and foreign food composition tables as well as analytical data obtained from manufacturers (Ahlström et ai. 1972, Räsänen and Ahlström 1975). The children were interviewed by the same persons in winter and in summer. On both occasions the children were randomly distributed between the interview- ers. All the children in the present material were accompanied by the mother during both interviews. The mean daily consumption of foods and the intakes of energy and nu- trients were calculated. Significance of the differences between the means was tested by Student’s t-test as described by Steel and Torrie (1960). In tables the statistical significance of the differences is expressed as follows: 0.01 < p < 0.05 0.001 < P < 0.01 ** p < 0.001 *** 450 Results The mean daily consumption of foods in summer and in winter is presented in Table 1. Differences between the two seasons in the composition of the diet were most evident in the following food groups: milk products other than milk, sour milk or cheese; inner organs and blood; vegetables; fruits and berries; and beverages. Table 1. Mean daily intake of foods in summer and in winter in grammes per 24 hours. Mean values and standard deviations of means (n = 158). Summer Winter Signif. of. cli ff. Milk 573.5 ± 303.8 618.0 ± 270.7 - Sour milk 111.8 ± 191.0 52.3 ± 120.7 ** Cheese 6.7 ± 17.6 6.3 ± 13.8 Other milk products 50.0 ± 67.0 18.0 ± 49.4 *** Butter, margarine, oils 41.4 ± 27.7 43.3 ± 22.7 Eggs 19.2 ± 26.6 25.4 ± 35.8 - Beef 14.1 ± 35.4 7.4 ± 17.9 * Pork 9.3 ± 38.3 16.0 ± 38.6 - Other meats 12.7 ± 26.5 21.9 ± 37.6 * Inner organs and blood 1.8 ± 8.5 12.3 ± 32.1 *** Sausages and other meat products 71.5 4_: 94.4 65.9 ± 77.6 Fish 18.8 ± 45.8 8.9 ± 27.9 • Rye 86.2 ± 84.5 71.7 ± 67.6 Wheat 77.2 ± 58.8 98.2 ± 72.2 ** Other cereal products 27.3 ± 40.2 16.3 ± 24.3 ** Potatoes 131.5 ± 114.2 142.8 ± 124.6 Roots 13.3 ± 30.1 16.0 ± 34.0 Legumes and nuts 4.9 ± 21.2 7.7 ± 25.4 Other vegetables 92.7 ± 98.9 35.7 ± 51.2 *•* Fruits and berries 133.4 ± 164.5 230.2 ± 207.3 *** Sugar and candy 41.4 ± 32.3 51.4 ± 48.4 * Beverages 236.4 ± 216.2 137.4 ± 198.4 *** Other foods 3.2 ± 5.0 3.0 ± 4.4 - The differences in the consumption of the various food groups in winter and summer had the same trend in the three age groups. The difference in »other milk products» was due mainly to the greater consumption of ice cream in summer than in winter. The diets of the 9- and 13-year-dlds included signi- ficantly more blood and liver dishes in winter than in summer. In the 5-year- old group the difference was not statistically significant. In all the age groups more vegetables were used in summer, the difference being mainly due to higher consumption of cucumbers, tomatoes and rhubarb. In winter the children ate nearly twice as much fruits and berries as in summer, particularly the consumption of citrus fruits, citrus juices and apples was high in winter. The seasonal difference in the mean daily consumption of beverages was due to the greater consumption of soft drinks by children in summer. In all age groups the mean intakes of energy and most nutrients were notably similar in summer and winter (Table 2). The mean intake of iron in the whole material was significantly higher in winter than in summer. This difference was seen in all age groups, but it was statistically significant only in the 9-year-old group. The mean iron content of the children’s diet was 5.0 mg/1000 kcal in summer and 5.8 mg/1000 kcal in winter. Likewise the intake of vitamin A was higher in winter. A very clear seasonal difference between the diets was seen in ascorbic acid, the intake of this being greater in winter. In both summer and winter about 12.5 % of the total intake of energy was obtained from protein. Fat accounted for 40.6 % of the total energy intake in summer and for 40.3 % in winter, and carbohydrate for 46.9 % and 47.2 %, respectively. The supply of energy and nutrients by the different food groups is presented in Table 3. The role of milk and milk products as source of energy and nutrients was somewhat greater in summer than in winter. The rather general use of low-fat milk products in winter, especially that of milk with fat content of 2.5 % instead of standard milk (fat content 3.9 %), reduced the proportion on fat intake from milk and milk products in this season below the summer level. Only slight seasonal differences were found in the total amount of eggs, meat and fish consumed. This food category, however, contained in winter consid- erably more inner organs and blood, which raised its importance as a source of nutrients to a clearly higher level than in summer. The seasonal variations were notably great in iron, vitamin A and riboflavin. Conversely, the propor- tionate share of cereal and cereal products in supplying nutrients was smaller in winter than in summer. The vegetable group and the fruit and berry group changed positions as ascorbic acid sources in summer and winter. The persen- tage share of fruits and berries was greatly increased in winter, yielding over a half of the total ascorbic acid intake, whereas vegetables were of minor impor- tance in this season. Table 2. Mean values and standard deviations of intake of energy and some nutrients in summer and in winter (n = 158). Summer Winter Signif. of diff. Energy, kcal 2 221 ±823 2 256 ± 686 MJ 9.3 ± 3.4 9.4 ± 2.9 - Protein, g 71.1 ± 25.8 72.1 ± 22.3 Fat, g 102.5 ± 47.9 103.5 ± 38.6 Carbohydrate, g 267.0 ± 103.0 272.5 ± 89.9 Calcium, mg 1095 ±430 1080 ± 406 - Iron, mg 11.2 ± 4.8 13.0 ± 6.8 •• Vitamin A. ret. eq., /«g 1 OC4 ±9Ol 1431 ±2 034 * Thiamin, mg 1.3 ± 0.6 1.4 ± 0.5 - Riboflavin, mg 2.4 ± 0.9 2.6 ± 1.1 Niacin, mg 11.7 ± 6.1 12.0 ± 5.7 - Niacin eq., mg 26.8 ± 10.7 27.1 ± 9.4 Ascorbic acid, mg 81.1 ± 54.7 104.4 ± 70.9 *** 451 452 Table 3. Percentage distribution of energy and some nutrients among the different food groups. 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