2.1.1 MARCO TEÓRICO GENERAL
3.1 EL MODELO ECONOMÉTRICO 1 FORMULACIÓN
A total of 91 children, representing a 10 % o f all children whose first food diaries at 6 months o f age had been completed and returned by their parents / carers (N = 900) was randomly selected. This was done to investigate the dietary behaviours o f children at 6 months o f age.
Gender
Fifty seven percent (n = 52) of children were boys and 43 % (n = 39) were girls. There was no statistically significant difference in the proportion o f boys and girls [Chi sq. = 1.86, d f = 2, p = 0.17]. The proportion of boys and girls whose parents agreed to participate in the study (N = 1380) were, 52 % (N = 715) and 48 % (N = 665),
respectively. There was no statistically significant difference between the proportion o f each gender in this sample, too [Chi sq. = 1.67, df = 1, P= 0.2] (Table5.1).
Table 5.1 The proportions of girls and boys participating in the study and the result of random selection of 6 months dietary data
Sample Boys Girls Total
Original 714 (52%) 666 (48%) 1380(100%)
Random 52 (57%) 39 (43%) 91 (100%)
Dietary Behaviours at 6 Months
The mean daily frequency o f total eating / drinking events, frequency of consumption of NMES and frequency of consumption of a selected categories o f foods and drinks were investigated. The mean daily intakes of energy, carbohydrates, sugars, starch as well as the mean percentages of energy intakes from each nutrients (carbohydrates, sugars, starch) were also studied. The details are as follows:
The Frequency of Total Eating / Drinking Events at 6 M onths
The mean daily total eating / drinking events in this group o f children was 7.0 (SD 1.8) times per day (Table 5.2). The mean daily total eating / drinking events in boys was 7.0 (SD 3.4) times per day compared with 6.9 (SD 1.8) times per day in girls. The difference in means was not statistically significant [t = 0.245, d f = 89, p = 0.8].
The Frequency of Consumption of Non-milk Extrinsic Sugars (NMES) a t 6 Months
The mean daily frequency of consumption of NMES in this group of children was 3.4 (SD 1.1) times per day (Table 5.2). The frequency o f consumption o f NMES comprised 49 % o f the total eating / drinking events per day. The mean frequency of consumption of NMES in boys was 3.4 (SD 1.1) times per day compared with 3.3 (SD 1.1) times per day in girls. There was no significant correlation between frequency of consumption of NMES and the total eating / drinking events [r = 0.05, p = 0.7].
Foods and D rinks Categories at 6 M onths
The means o f frequency o f consumption o f each 18 different categories o f foods and drinks related to dental health were investigated (Appendix 10). Some children did not consume some o f the categories. Figure 5.1 shows the proportions o f children whose mean daily frequency o f consumption o f different categories o f foods / drinks were greater than zero. The mean daily frequency of consumption o f different categories of foods and drinks reported in this chapter, included all children in the sample; those who had not consumed the categories of foods and drinks (mean = 0) and those who had (mean > 0). These are shown in Table 5.2.
Over half (54%) o f children had consumed “water” as drink compared with 45%, 9%, and 3% who had consumed “sugared drinks”, “fruit juice”, and “sugar free drinks”, respectively. Only one child had consumed “sugared beverage”.
The proportion of children who consumed “formula milk” (66%) was nearly two times higher than the proportion o f children who had “breast milk” (34%). Thirty six per cent of children had consumed “cow’s milk” compared with 2% of children who had “soya milk”.
Overall 87% o f children had “milk dessert” compared with 56% who had “ non milk dessert”. Ninety nine per cent of children had consumed “sugared cereals”, 75% “fhiit” and about one third (36%) o f children had consumed “cakes”. Seventeen per cent and 11% o f children had consumed “chocolate” and “crisps”, respectively. None of the children had “sweets”.
The mean daily frequency o f consumption o f formula milks (2.3 times per day) was highest among all food / drink categories investigated. It was 2, 8 and 23 times higher than the mean frequency o f consumption o f “breast milk”, “cow’s milk” and “soya milk”, respectively. The mean frequency o f consumption o f water (0.5 times / day) was slightly lower than the mean frequency of consumption o f “sugared drink” at 0.6 times per day. Nevertheless, it was nearly 5 times higher than the mean frequency of
consumption o f “fruit juice” and “sugar free drinks”. The mean frequency o f
Table 5.2 The mean daily frequency of total eating / drinking events and
frequency of consumption of NMES and different categories of foods and drinks at 6 months of age.
FOOD / DRINK CATEGORY MEAN (SD) MEDIAN M IN MAX
Total eating/drinking events 7.0 (1.8) 7.0 4.0 13.0
Total NMES 3.4 (1.1) 3.3 1.0 7.0 Water 0.5 (0.7) 0.0 0.0 3.0 Sugared drinks 0.6 (0.9) 0.0 0.0 6.0 Fruit juice 0.0 (0.4) 0.0 0.0 2.7 Sugared beverage 0.0 0.0 0.0 0.0 Sugared milk 0.0 (0.0) 0.0 0.0 0.3 No sugared drink 0.1 (0.7) 0.0 0.0 6.0 Formula milk 2.3 (2.0) 2.7 0.0 9.0
Formula milk containing NMES 0.4 (1.1) 0.0 0.0 5.7
Breast milk 1.3 (2.3) 0.0 0.0 9.7
Soya milk 0.0 (0.6) 0.0 0.0 4.0
Cow’s milk 0.3 (0.7) 0.0 0.0 4.3
Milk dessert 1.0 (0.7) 0.0 0.0 4.0
Non milk dessert 0.4 (0.5) 0.0 0.0 2.3
Sugared cereals 1.1 (0.4) 1.0 0.0 2.3 Fruit 0.5 (0.5) 0.3 0.0 2.0 Cakes 0.2 (0.5) 0.0 0.0 3.0 Chocolate 0.0 (0.2) 0.0 0.0 1.7 Crisps 0.0 (0.2) 0.0 0.0 1.7 Sweets 0.0 0.0 0.0 0.0
120.00 100.00 80.00 I 60.00 -
I
40.00 - 20.00 H i .00 J 99 87 75 36 36 34 12 11 ofoods and drinks categories
Figure 5.1 The percentage of children who consumed diffemt categories of foods / drinks (mean > 0) at 6 months of age.
N utrient and Energy Intake at 6 M onths
Table 5.3 shows the total intakes o f energy, carbohydrates, sugars, and starch as well as percentages o f energy intakes from carbohydrate, sugar and starch. The total
carbohydrate intakes were produced by using Food Tables and the information from baby food manufacturer companies, when available. Some manufacturers (particularly some baby food manufacturers) did not provide this information on the amounts of sugar and starch contents. Therefore, the calculated percentages o f energy intakes from sugars and starch did not add up to the percentage of energy intake provided by the carbohydrate.
Energy: The mean energy intake for all children in this sample was 838.1(SD 164.7) Kcal per day. The range in energy intake was large, for example the lowest 2.5
percentile o f children had 544.6 Kcal / day or less compared with the upper 2.5 % of children who had 1212.3 Kcal / day (Table 5.3) The mean energy intake o f boys was greater than of girls, and the difference in the means was statistically significant [t = 2.486, d f = 88, p = 0.015] (Table 5.3). The range between upper and lower 2.5 percentiles of energy intakes in boys was greater than in girls (Table 5.3).
The mean percentage of energy intake from carbohydrates in all children was 47.3 per cent. The mean percentage o f energy intakes from carbohydrates in boys and girls were 46.7 and 48.1 per cent, respectively
The mean percentage of energy intake from sugars was 29.6 (SD 8.5). The mean percentage of energy intake from sugars for boys was 29.2 (SD 7.8) compared with 31.5 (SD 9.1) per cent for girls. The difference in means between each gender was
statistically significant [Mann - Whitney U test, Z = -2.09, p = 0.04].
The mean percentage of energy intake from starch was 10.9 (SD 5.4). The mean percentage of energy intake from starch for boys was 11.1 (SD 5.4) and for girls was
10.4 (SD 5.5). The difference in means between each gender was not statistically significant [t= 0.59, df = 88, p = 0.5].
C arbohydrates: The average daily intakes of total carbohydrates was 104.3 (SD 20.0) grams / day. The range for carbohydrates intakes was large for example, the
lowest 2.5 percentile o f children consumed 66.9 g / day or less compared with 147.0 g a day consumed by those at the upper 2.5 percentile (Table 5.3).
The mean intake o f carbohydrates in boys (106.9 g / day) was slightly higher than in girls (100.9 g / day). The difference in the means was not statistically significant [t = 1.41, df = 88, p = 0.16]. At the lower and upper 2.5 percentiles, boys were consuming 67.0 and 155.2 grams a day, respectively. The lowest 2.5 percentile o f girls were consuming 61.0 g / day compared with 133.5 g / day by the upper 2.5 percentiles. (Table 5.3).
Sugars: The total sugars included both extrinsic (milk and non - milk extrinsic) and intrinsic sugars. The average daily intake of sugars was 65.0 (SD 20.5) grams. The range of intake was large, for example, children at the lower 2.5 percentile were
consuming 20.0 g / day compared with children at the upper 2.5 percentile whose mean intake of sugars was 95.0 g / day. The mean total intake o f sugars for boys (65 7 g / day) was slightly higher than for girls (64.1 g / day). The difference in the means was not statistically significant [t = 0.346, df = 88, p = 0.73] (Table 5.3).
Starch: The average daily intake o f starch by children in this sample was 24.7 (SD 13.5) g / day. The starch intakes by children ranged between 0.2 g / day at the lower 2.5 percentile to 21.0 g / day at the upper 2.5 percentile. The mean starch intake for boys (25.9 g / day) was higher than for girls (23.0 g./.day). The difference in the means between boys and girls was not statistically significant [Mann-Whitney test, Z = -1.19, p = 0.23] (Table 5.3).
Table 5.3 The mean daily intakes of energy (Kcal / day), carbohydrates, sugars and starch (g / day) at 6 months of age by gender
M ean (SD)
Median Min Max Lower
2.5 % U pper 2.5 % Energy All children 838.1 (164.7) 844.0 495.0 1252.0 544.65 1212.3 Boys 874.0 (154.1) 876.5 495.0 1252.0 524.9 1246.1 Girls 789.0 (167.9) 764.0 543.0 1155.0 543.0 1043.0 Carbohydrates All children 104.3 (20.0) 104.3 61.0 158.1 67.0 146.6 Boys 106.9 (18.7) 348.2 66.5 158.1 67.0 155.2 Girls 100.9 (21.5) 100.3 61.0 139.8 61.0 133.5 Sugars All children 65.0 (20.5) 65.0 14.6 118.6 20.0 95.0 Boys 65.7 (21.8) 67.3 14.6 118.6 16.71 117.4 Girls 64.2 (18.9) 62.5 20.0 94.8 19.96 94.4 Starch All Children 24.7 (13.5) 24.9 0.0 57.1 0.20 21.0 Boys 25.9 (12.7) 28.1 0.0 45.8 Girls 23.0 18.6 3.0 57.1
P art 2: 12 M onths Random Group
A total of 67 children, representing a 10% o f all children whose food diaries at 12 months o f age had been completed and returned by their parents / carers (n = 605) was randomly selected. This was done to investigate the eating habits o f children at 12 months o f age. The details of sample selection and data analysis are explained in chapters 3 and 4, respectively.
G ender
Fifty two per cent (n = 35) of children were boys and 48% (n = 32) were girls. There was no statistically significant difference in the proportion o f boys and girls. The proportion of each gender in this sample was similar to those who initially participated in the study (Table 5.4).
Table 5.4 The proportions of girls and boys participating in the study and the result of random selection of 12 months dietary data
Sample Boys Girls Total
Original 714 (52%) 666 (48%) 1380(100%)
Random 35 (52 %) 32 (48 %) 67 (100%)
Dietary Behaviours at 12 Months
Table 5.5 shows the mean daily frequency o f total eating / drinking events, the mean daily frequency of consumption of foods and drinks containing non-milk extrinsic sugars (NMES) and selected categories of foods and drinks. The mean total intakes of
Total Eating / Drinking Events at 12 Months
The mean total eating / drinking events in this group of children was 6.4 (SD 1.5) times per day (Table 5.5). The mean total eating / drinking events in boys at 6.3 (SD
1.4) times per day was similar to that of girls at 6.4 (1.7) times per day. The difference in means was not statistically significant [t = -0.27, d f = 65, p = 0.0.8].
Non-milk Extrinsic Sugars (NMES) at 12 Months
The mean frequency of consumption of NMES in this group o f children was 4.0 (SD 1.1) times per day (Table 5.5). The mean frequency o f consumption o f NMES
comprised 62% o f the mean total eating / drinking events per day. The mean frequency of consumption o f NMES in boys at 4.0 (SD 1.3) times per day was similar to that of girls at 4.0 (SD 1.0) times per day. There was no difference in the mean frequency of consumption of NMES between boys and girls [t= 0.006, df = 65, p =1.0]. There was a highly significant correlation between the mean total eating / drinking events and frequency o f consumption o f NMES [r = 0.52, p = 0.0001] (Figure 5.2).
Foods and Drinks Categories at 12 Months
The means o f frequency of consumption o f each 18 categories o f foods and drinks related to dental health were investigated and are shown in Table 5.5. Figure 5.3 shows the proportions of children who consumed different categories o f foods / drinks at 12 months. Approximately half (49%) o f children had consumed “water” and “sugared drinks”, whereas “fruit juice” was consumed by less than one-fourth o f children. The percentage of children who consumed “no sugar drinks” was 8% and only 2% of children had consumed “sugared beverage”.
Amongst milk categories while “cow’s milk” was consumed by 80 % of children, “formula milks” and “formula milks with NMES” had been consumed by 18 and 8 per cent o f children, respectively. Only a small number o f children (2%) had consumed “soya milk”.
Compared with other foods and drinks, “milk dessert” was the most popular food among this group of children. Almost all children (98 %) had consumed this category o f food compared with 45% o f them who had consumed “non milk dessert”.
A large number of children (91%) had consumed “cakes” and more than half (56%) of them had consumed “crisps”. Forty per cent o f children had consumed “chocolate”
whereas “sweets” was consumed by only 8 % of children. Eighty five per cent of children had consumed “fruits”.
The mean frequency of consumption o f “sugared drink” at 0.9 times / day was almost similar to the of “water”, at 0.8 times per day. The mean frequency o f consumption of “fruit juice” was 0.2 times per day. The mean frequency of consumption o f “no sugared drinks” was very low (0.04 times / day).
The mean daily frequency o f consumption of “cow’s milk” at 2.3 times per day was the highest amongst milk categories, “formula milks”, “breast milk”, and “soya milk” were consumed 0.3, 0.2, and 0.01 times per day, respectively
The mean frequency o f consumptions o f “sugared cereals", “cakes”, “chocolate”, “crisps” were 0.9,0.9, 0.2 and 0.2 times per day, respectively. The mean frequency of consumption of “sweets” was very low (0.05 time / day). The mean frequency of consumption of “fruits” was 0.9 times /day.
The mean frequency o f consumption of “milk dessert” was 1.1 times per day and of “non milk dessert” 0.2 times per day.
Table 5.5 The mean daily frequency of total eating / drinking events and
frequency of consumption of NMES and different categories of foods and drinks at 12 months of age.
FOOD / DRINK CATEGORY MEAN (SD) MEDIAN MIN MAX
Total eating/drinking events 6.4 (1.5) 1.5 3.3 10.0
Total NMES 4.0 (1.1) 4.0 2.0 9.3 Water 0.8 (1.2) 1.2 0.0 5.3 sugared drinks 0.8 (1.2) 0.0 0.0 4.3 Fruit juice 0.2 (0.5) 0.5 0.0 3.3 Sugared milk 0.0 0.0 0.0 0.0 Sugared beverage 0.0 (0.0) 0.04 0.0 0.3 No sugared drink 0.04 (0.2) 0.2 0.0 1.3 Formula milk 0.3 (0.8) 0.0 0.0 3.7
Formula milk containing NMES 0.1 (0.5) 0.4 0.0 2.3
Breast milk 0.2 (0.8) 0.0 0.0 5.7
Soya milk 0.01 (0.04) 0.0 0.0 0.3
Cow’s milk 2.3 (1.1) 0.0 0.0 1.0
Milk desserts 1.1 (0.5) 1.0 0.0 2.0
Non milk desserts 0.2 (0.4) 0.3 0.0 1.7
Sugared cereals 0.9 (0.4) 1.0 0.0 2.0 Cakes 0.9 (0.7) 0.7 0.0 2.3 Fruits 0.9 (0.7) 0.7 0.0 3.3 Chocolates 0.2 (0.3) 0.3 0.0 1.0 Crisps 0.2 (0.3) 0.3 0.0 1.3 Sweets 0.05 (0.2) 0.04 0.0 1.0
C/D :z; q -i o
§
t
Ü «4-1 0 g1
I
10 8 a □ 6 □ a o o 4 2 0 •2 16 4 6 8 12 14 2 10Mean daily eating / drinking events
Figure 5.2 The correlation between the mean total eating / drinking events and frequency of consumption of NMES at 12 months Ir = 0.5, p = 0.0001].
120
100 r " 95
I
Food / drink category
Figure 5.3 The percentage of children who consumed different categories of food and drinks at 12 months.
For definition o f categories see Appendix 10
Nutrient and Energy Intakes at 12 Months
Table 5.6 shows the total intakes o f carbohydrate, sugars, starch and energy as well as percentage o f energy intakes from carbohydrates sugars and starch.
Energy: The mean energy intake o f all children in this sample was 989.7 (SD 187.5) Kcal per day. The range in energy intake was large, for example the lowest 2.5 percentile o f mean was 621.4 Kcal / day compared with the upper 2.5 % o f children who had 1483.9 Kcal / day (Table 5.6). The mean energy intakes for boys and girls were 982.9 (SD 189.4) and 996.9 (SD 188.3) Kcal / day, respectively. There was no significant difference in the mean energy intake between boys and girls [t = -0.29,df= 62, p = 0.8] (Table 5.6). The upper and lower 2.5 percentiles of energy intakes in boys were 582.0 an d l052.0 Kcal / day, respectively. The upper and lower 2.5 percentiles of energy intakes for girls were 645.0 and 1096.0 kcal / day (Table 5.6).
The mean percentage of energy intake from carbohydrates in all children was 46.3 (SD 6.1). The mean percentage of energy intakes from carbohydrates were 46.7 (SD 6.7) and 45.6 (SD 5.4) per cent in boys and girls, respectively. The difference in the means between boys and girls was not statistically significant [t = 0.72, d f = 62, p =0.5].
The mean percentage of energy intake from sugars was 24.0 (SD 6.1). The mean percentage o f energy intake from sugars for boys was 24.3 (6.79) compared with 23.7 (SD 5.5) per cent for girls. The difference in means between each gender was not statistically significant [t = 0.4, df = 62, p = 0.7].
The mean percentage of energy intakes from starch was 17.3 (SD 8.9). The mean percentage o f energy intake from starch for boys was 15.9 (SD 9.1) and for girls wasl8.8.(SD 8.7). The difference in means between each gender was not statistically significant [t= -1.29, df = 62, p =0.2].
The mean intake o f carbohydrate in boys at 122.1 (SD 27.8) g / day was slightly higher than in girls at 121.4 (SD 28.9) g / day. The difference in the means was not statistically significant [t = 0.11, df = 62, p = 0.9]. At the lower and upper 2.5
percentiles, boys were consuming 75.4 and 135.3 grams a day, respectively. The lowest 2.5 percentile o f girls were consuming 74.5 g / day compared with 138.34 g / day by upper 2.5 percentiles. (Table 5.6).
Sugars: The total sugars included both extrinsic (milk and non - milk extrinsic) and intrinsic sugars. The average daily intake o f sugars was 62.9 (SD 17.3) grams / day. The range o f intake was large; for example, children at the lower 2.5 percentile were consuming 25.2 g / day compared with children at the upper 2.5 percentile whose intake of sugars was 99.7 g / day. The mean total sugars for boys 63.46 (SD 18.7) g / day) was slightly higher than for girls 62.3 (SD 16.0) g / day. The difference in the means was not statistically significant [t = 0.27, df =62, p = 0.79] (Table 5.6).
Starch: The average daily intake of starch by children in this sample was 53.4 (SD 23.1) g / day. The starch intakes by children ranged between 20.0 g / day at the lower 2.5 percentile to 134.1 g / day at he upper 2.5 percentile. The mean starch intake for boys 52.9 (SD 18.6) g / day was higher than for girls 54.2 (SD 27.4) g / day. The difference in the means between boys and girls was not statistically significant [t = -0.2, df = 62, p = 0.8] (Table 5.6).
Table 5.6 The m ean daily intakes of energy (Kcal / day), carbohydrates, sugars and starch (g / day) at 12 months of age by gender.
M ean (SD)
M edian Min Max Low er
2.5 % U pper 2.5 % Energy All children 989.7 (187.5) 969.0 582.0 116.1 621.3 1483.9 Boys 982.9 (189.4) 958.0 582.0 1607.0 582.0 1052.0 Girls 996.9 (188.3) 979.0 645.0 1410.0 645.0 1096.0 C arbohydrates All children 121.8 (28.2) 117.8 74.5 206.9 75.1 198.4 Boys 122.1 (27.8) 122.3 75.4 193.3 75.4 135.3 Girls 121.4 (29.0) 116.6 74.5 206.9 74.5 138.3 Sugars All children 62.9 (17.3) 59.9 21.9 101.2 25.2 99.7 Boys 63.45 (18.7) 60.3 21.92 101.6 21.9 77.0 Girls 62.3 (18.7) 59.3 32.9 98.8 32.9 69.5 Starch All Children 53.5 (23.1) 49.9 18.6 160.1 20.0 134.1
P a rt 3: 18 M onths Random G roup
A total o f 34 children, representing a 10 % of all children whose third food diaries at 18 months o f age had been completed and returned by their parents / carers (n =259), was randomly selected. This was done to investigate the feeding behaviours of children at 18 months o f age. The method o f sample selection is explained in chapter 3 and 4, respectively.
Gender
Fifty nine percent (n = 20) o f children were boys and 41% (n = 14) were girls. There was no statistically significant difference in the proportion of boys and girls [Chi Sq. =
1.06, df = 1, p = 0.3]. The proportion o f each gender in this sample was similar to those who initially participated in the study (Table 5.7).
Table 5.7 The proportions of girls and boys participating in the study and the result of random selection of 18 months dietary data
Sample Boys Girls Total
Original 714 (52%) 666 (48%) 1380(100%)
Random 20 (52%)0 14 (41%) 34 (100%)
Dietary Behaviours at 18 M onths
Table 5.8 shows the mean daily frequency o f total eating / drinking events, frequency of consumption of NMES and categories of foods and drinks. The mean total intakes of energy, carbohydrates, sugars, starch as well as the mean percentages o f energy intakes from each nutrients (carbohydrates, sugars, starch) are summarised in Table 5.9. The details are as follow:
Total Eating / Drinking Events at 18 Months
The mean total eating / drinking events in this group o f children was 6.9 (SD 2.0) times per day (Table 5.8). The mean total eating drinking events in boys was 7.1 (SD 2.4) times per day compared with 6.4 (SD 1.21) times per day in girls. The difference