L. C. A. Craig

Repeatability and validity of a food frequency questionnaire in free-living older people in relation to cognitive function

Objectives: To determine the repeatability and validity of a self-administered, 175-item food frequency questionnaire (FFQ) in free-living older people and to assess whether these are influenced by cognitive function.Participants and setting: 189 free-living people aged 64–80y were recruited from participants in a previous study.Design: To assess repeatability, 102 (52M, 50F) participants completed the FFQ on two occasions three months apart. To assess validity, another 87 participants (44 M, 43 F) completed the FFQ and a four-day weighed diet record three months later. 25 nutrients were studied.Results: For repeatability, Spearman rank correlation coefficients were above 0.35 (p<0.05) for all nutrients. Cohen’s weighted Kappa was above 0.4 for all nutrients except starch, riboflavin, retinol, β-carotene, and calcium. There were no substantial differences in correlation coefficients between sub-groups divided by short-term memory test score. There was no clear pattern for correlation coefficients in sub-groups divided by executive function test score. For validity, the Spearman rank correlation coefficients were above 0.2 (p<0.05) for all nutrients except fat, mono-unsaturated fatty acids, niacin equivalents and vitamin D, and Cohen’s weighted kappa was above 0.4 for alcohol and was above 0.2 for 13 other nutrients. Participants in the lowest-score groups of short-term memory and executive function had the lowest median Spearman correlation coefficient.Conclusions: The FFQ had reasonable repeatability and validity in ranking nutrient intakes in this population though the results varied between nutrients. Poor short-term memory or executive function may affect FFQ validity in ranking nutrient intakes.

Assessing the relative validity of the Scottish Collaborative Group FFQ for measuring dietary intake in adults

OBJECTIVEnTo assess the relative validity of the latest version of the Scottish Collaborative Group (SCG) FFQ (version 6.6) in adults living in Scotland.nnnDESIGNnA cross-sectional validation study. Participants completed the self-administered, 169-item SCG FFQ followed by a 7 d, non-weighed food diary. Energy and energy-adjusted macronutrients and micronutrients were examined for relative validity through Spearmans correlation, the percentage of classification into thirds of intake, Cohens weighted kappa (κ w) and Bland-Altman analysis.nnnSETTINGnGeneral population living in Scotland.nnnSUBJECTSnNinety-six adults aged 18-65 years.nnnRESULTSnSpearmans correlation coefficients ranged from 0·21 (retinol) to 0·71 (Mg). A median of 52 % of adults were correctly classified into thirds of intake (range: 42 % (PUFA, MUFA and Fe) to 64 % (percentage energy from carbohydrates)) and 8 % were grossly misclassified into opposite thirds of intake (range: 3 % (carbohydrates, percentage energy from carbohydrates) to 19 % (thiamin)). Values of κ w ranged between 0·20 (PUFA, β-carotene) to 0·55 (percentage energy from carbohydrates). In the Bland-Altman analysis, the smallest limits of agreement, when expressed as a percentage of the mean intake from the FFQ and food diary, were seen for the main macronutrients carbohydrates, fat and protein.nnnCONCLUSIONSnAs in the previous validation study more than 10 years ago, the FFQ gave higher estimates of energy and most nutrients than the food diary, but after adjustment for energy intake the FFQ could be used in place of non-weighed food diaries for most macronutrients and many micronutrients in large-scale epidemiological studies.

Using food intake records to estimate compliance with the Eatwell Plate dietary guidelines

BACKGROUNDnThe UK Eatwell Plate is consumer based advice recommending the proportions of five food groups for a balanced diet: starchy foods, fruit and vegetables, dairy foods, nondairy sources of protein and foods and drinks high in fat or sugar. Many foods comprise ingredients from several food groups and consumers need to consider how these fit with the proportions of the Eatwell Plate. This involves disaggregating composite dishes into proportions of individual food components. The present study aimed to match the diets of adults in Scotland to the Eatwell Plate dietary recommendations and to describe the assumptions and methodological issues associated with estimating Eatwell Plate proportions from dietary records.nnnMETHODSnFoods from weighed intake records of 161 females and 151 males were assigned to a single Eatwell group based on the main ingredient for composite foods, and the overall Eatwell Plate proportions of each subjects diet were calculated. Food group proportions were then recalculated after disaggregating composite foods.nnnRESULTSnThe fruit and vegetables and starchy food groups consumed were significantly lower than recommended in the Eatwell Plate, whereas the proportions of the protein and foods high in fat or sugar were significantly higher. Failing to disaggregate composite foods gave an inaccurate estimate of the food group composition of the diet.nnnCONCLUSIONSnEstimating Eatwell Plate proportions from dietary records is not straightforward, and is reliant on methodological assumptions. These need to be standardised and disseminated to ensure consistent analysis.

Frequency of meal and snack consumption and nutrient intake in schoolchildren in Scotland: term-time v . holidays and weekdays v . weekends

Increasing levels of childhood obesity have raised concerns about the eating habits of children. The aim of the present study was to investigate meal and snack patterns and nutrient intakes of Scottish schoolchildren comparing term-time v. holidays and weekday v. weekends during term-time. As part of a national cross-sectional dietary survey of Scottish children conducted in 2006, a subsample of children aged 5–17 years completed a 4 d non-weighed-diet diary (n 156; eighty-one boys and seventy-five girls). These diaries were analysed to describe the frequency of meal and snack consumption per d and average daily nutrient intakes. Eating events were defined as meals or snacks, with each eating event being separated by a minimum of 30 min. The definition of meals and snacks was adapted from Kelly et al. in which foods were coded into ‘core’ and ‘non-core’ foods. Meals were defined as an eating event containing one or more ‘core’ foods, while a snack contained no ‘core’ foods. The average number of meals and snacks eaten per d and the average daily nutrient intakes were compared between subgroups defined by age (5–11 years and 12–17 years), gender, term-time or holidays and weekdays or weekends. Comparison of term-time and holiday included intakes from only weekdays (excluding the weekend) and excluded children whose diary spanned term-time and holiday. The within-subject analysis comparing week and weekend days was based on diaries only completed during term-time (n 106). The median) number of eating events per child for the whole sample (n 156) was 5.3 (interquartile range (IQR) 4.8–6.0) per d, and comprised 3.3 (IQR 2.8–3.5) meals plus 2.0 (IQR 1.5–2.8) snacks. There were no significant differences in the number of meals and snacks eaten between age-groups or between term-time v. holiday subgroups. A significantly higher number of meals were eaten per d by boys (3.3 (IQR 3.0–3.5)) than by girls (3.0 (IQR 2.8–3.5); P = 0.032) in the whole sample. A significantly higher number of meals were eaten on weekdays (3.0 (IQR 3.0–3.7)) than weekends (3.0 (IQR 3.0–3.0); P = 0.015) and this pattern remained when data from term-time and holiday were combined. The Tables show the mean and 95% confidence interval (CI) of average daily nutrient intakes for term-time v. holidays and weekdays v. weekends (term-time only). There were no significant differences in the average daily nutrient intakes between these groups (P<0.05).

Socio-economic differences in diet, physical activity and leisure-time screen use among Scottish children in 2006 and 2010 : are we closing the gap?

OBJECTIVEnTo investigate socio-economic differences in childrens diet, activity and inactivity and changes in these differences over 4 years during which new policies on food in schools were introduced.nnnDESIGNnTwo cross-sectional surveys in which diet was assessed by FFQ and physical activity and inactivity were assessed by interviewer-administered questionnaire. Socio-economic status was assessed by the area-based Scottish Index of Multiple Deprivation.nnnSETTINGnScotland, 2006 and 2010.nnnSUBJECTSnChildren aged 3-17 years (n 1700 in 2006, n 1906 in 2010).nnnRESULTSnIn both surveys there were significant linear associations between socio-economic deprivation and intakes of energy, non-milk extrinsic sugars (NMES) as a percentage of food energy, sugar-sweetened beverages, confectionery, crisps and savoury snacks and leisure-time screen use (all higher among children in more deprived areas), while intakes of fruit, fruit juice and vegetables showed the opposite trend. In 2010 children in more deprived areas engaged in more physical activity out of school than those in more affluent areas, but between 2006 and 2010 there was an overall reduction in physical activity out of school. There were also small but statistically significant overall reductions in intakes of confectionery, crisps and savoury snacks, energy and NMES and saturated fat as a percentage of food energy, but no statistically significant change in socio-economic gradients in diet or activity between the two surveys.nnnCONCLUSIONSnInterventions to improve diet and physical activity in children in Scotland need to be designed so as to be effective in all socio-economic groups.

Inequalities in diet, obesity, physical activity and physical inactivity in children in Scotland in 2010

The 2010 Survey of Diet Among Children in Scotland continued the work of the 2006 Survey of Sugar Intake Among Children in Scotland to monitor progress towards the Scottish Dietary Targets for non-milk extrinsic sugars (NMES) and saturated fatty acid (SFA) intakes in children. This analysis investigated inequalities in dietary intake, the prevalence of overweight and obesity, and levels of physical activity and inactivity in children in Scotland in 2010. Children aged 3–16 years were randomly selected across Scotland using the HM Revenue and Customs Child Benefit Register. After an opt-out exercise, the Scottish Collaborative Group Food Frequency Questionnaire (FFQ) (http://www.foodfrequency.org.uk) was mailed to parents for completion by the parent and/or child (depending on the age of the child). Fieldwork was carried out between June and November 2010. Fieldworkers checked the FFQ, asked about time spent in physical activities and in front of a screen (television, computer or games console), and measured height and weight. Overweight including obesity was defined as BMI ‡ 85 percentile using the UK 1990 centile charts. 1906 interviews were carried out and 1674 FFQs were available for dietary analysis (response rates 63% and 55% respectively). Analysis by level of deprivation used the 2009 version of the Scottish Index of Multiple Deprivation (SIMD). In 2010, the prevalence of overweight including obesity increased with deprivation from 25% in the least deprived quintile to 38% in the most deprived quintile (p = 0.009 for association). The mean time spent in front of a screen on an average day increased from 1.7 hours in the least deprived quintile to 2.2 hours in the most deprived quintile (p<0.001). However, the proportion of children who reported meeting physical activity recommendations was similar between SIMD quintiles (p = 0.914). When expressed as a percentage of food energy, NMES intakes increased significantly with deprivation, but total fat and SFA intakes did not differ by SIMD quintile.

Fat and sugar intake and physical inactivity: results from a national survey of children in Scotland

Children aged 3‐16y were randomly selected from 80 postcode sectors across Scotland using the Child Benefit Register. The Scottish Collaborative Group Food Frequency Questionnaire (FFQ) version C2 or C3 (http://www.foodfrequency.org.uk) was mailed to 2,352 parents for completion by the parent and/or child (depending on the age of the child). Interviews were carried out for 1700 children by trained field workers who asked about time spent at a television or computer screen on an average day as part of a larger survey. In total 1512 FFQs were returned, of which 51 incomplete FFQs and 70 with extreme energy intakes were excluded from the analysis. Usable data on both diet and physical inactivity were available for 1368 children. Intakes of total fat, SFA, NMES, crisps and savoury snacks, confectionery and non-diet soft drinks were significantly positively associated with time spent in front of a screen (see table). These associations remained statistically significant (p <0.001 for all) after adjusting for age and sex, except for the association with NMES (p = 0.128). Mean [95% CI] Number of hours spent at a screen on an average day

How many children meet dietary targets for both fat and sugar intake? A national survey of dietary intake of children in Scotland

Dietary targets are set for monitoring within the general population but they can provide a useful indication of the proportion of individuals meeting the dietary targets, as well as whether individuals are achieving a combination of the targets. The aim of the present study was to estimate the proportion of children in Scotland with intakes meeting the dietary targets of £ 35 % food energy from total fat, £ 11 % food energy from SFA and £ 10 % total energy ( £ 11 % food energy) from non-milk extrinsic sugar (NMES) as set out in the Scottish Diet Action Plan (1) . The Survey of Sugar Intake among Children in Scotland (2) conducted in 2006 assessed the dietary intake of a national sample of children across Scotland using a 140-item FFQ. The survey achieved a response rate of 67 %, with usable data for 1391 children aged 317 years. Dietary data were used to estimate the percentage of children meeting dietary targets for total fat, SFA and NMES intake. As a population these children achieved the dietary target for total fat, but approximately one-third of children had intakes > 35 % energy from total fat (see Table). Only 10 % of children met the targets for either SFA or NMES. There was no difference between boys and girls in the percentage meeting these targets. Younger children (3‐11years) were more likely than older children (12‐17 years) to meet targets for NMES (12.3% v. 7.2 %; P = 0.02) but less likely to meet targets for SFA (7.5% v. 14.3%; P < 0.001). Of the children 59 % met only one of the dietary targets and < 2 % of children met all three dietary targets. All the children that met the target for SFA also met the target for total fat intake, but only 15 % of those who met the total fat target also met the SFA target. A subsample of 156 children also completed a diet diary, which supported these findings and provided examples of the types of meals eaten across the day that achieved the targets.