Questionnaire sources for FFQs

At 32 weeks gestation, a self-competed FFQ with 43 food groups and eight basic foods was used to assess diets of the pregnant women [95]. The food list was developed by nutritionists in Bristol in 1990. It aimed to cover all the main foods consumed in Britain based on those used in a study in South Wales [96] and modified according to a study which had recently collected weighed food intake data among adults in Avon [97]. A separate shorter version of the FFQ was sent to the women to pass onto her partner if she chose to do so.

Participants were asked to report the frequency of consumption of these foods with the following possible responses:

• never or rarely
• once in two weeks
• 1-3 times a week
• 4-7 times a week
• more than once a day.

Portion sizes were not reported.  Further questions about more detailed aspects of the diet were asked such as: amount of fat on meat, type of bread, type of milk, type of fat used for spreading and cooking.

Participants were also asked if they were on a diet and if they were taking supplements.

Similar FFQs were used to assess the diet of mothers and their partners when the child was aged 4, 8 and 12/13 years. The food list was expanded to include 56 food groups and 12 drink groups based on experience gained when analysing the pregnancy FFQ and informed by foods and drinks recorded in the diet records collected on the 3.5-year-olds. Questions about how many alcoholic drinks per day were also asked in more detail.

The latest FFQ was administered to the cohort member, mothers, and fathers when the cohort member was aged 30– years. This followed the format of the previous FFQs and asked about frequency of consumption of a list of foods, as well as further questions on diet details (type of bread, type of milk, type of fat used, diet type e.g. vegan, etc.). 

Parents completed information about the child’s diet at age 4 weeks, 6, 15 and 24 months as part of postal questionnaires.  A range of questions were asked including: length of breastfeeding and/or formula, type of milk consumed, age at which various solids were introduced.

An infant FFQ was used at 6 and 15 months and 24 months. Responses to the infant FFQs included yes/no to whether the baby has ever had the food along with the age they started to eat it and the number of times per week. The questions cover ready-prepared baby foods, family foods and drinks. These questionnaires are not detailed enough to allow estimation of energy or nutrient intakes.

A full FFQ was completed by the main caregiver on behalf of the children when they were aged 3, 4, 7 and 9 years. This FFQ was adapted from the one used to assess maternal diet at 32 weeks gestation. There were some modifications over time; for example, from the age of 4 years, separate categories for coated poultry  and coated fish were included [98]. From the age of 7 years, separate questions were asked to establish what was eaten during school hours.

At age 12/13 years, the child completed a 54-item FFQ which included items specific to school dinners, as well as other foods normally eaten foods outside the home. At the same time, parents completed an 80-item FFQ on behalf of the child covering foods provided by the parents including packed lunches, but excluding school dinners and foods consumed outside the home. This FFQ was adapted from the maternal FFQ. These FFQ need to be used together to estimate energy and nutrient intakes and dietary patterns.

As part of the Children in Focus subsample, diet was assessed at 4, 8, 18 months and 3.5 years and 5 years using a three-day diet diary (one day diet diary at 4 months of age). These were not administered at the exact same ages as the FFQs. It was suggested that one weekend and two weekdays should be included in these diet diaries which did not have to be consecutive days.

The parents were asked to record all foods and drinks consumed by the child in household measures and bring the diary to the clinic visit where, if possible, any anomalies in the diary were clarified by a member of the nutrition team. From 3.5 years onwards questions about vitamin supplements, types of spread normally used and types of bread and milk used were also asked in a separate short questionnaire accompanying the diary.

At 7 years of age, parents of the whole cohort were sent a three-day diet diary to complete about their child. At age 10 and 13 years, the diary was designed for the child to complete with the help of their parents.

A mixture of questions about dieting, attitudes towards foods, disordered eating, and eating disorders were asked of the cohort member at ages 14, 16, 18, 23, 25, 24, 25, and 31 years.

Questions about dieting and disordered eating were asked of the mothers/carers when the cohort member was aged 17 years, and of both the mothers/carers and partners/fathers when the cohort member was aged 32 years.

During the pregnancy survey, mothers were asked about difficulties affording food, with the response options of: ‘very’, ‘fairly’, ‘slightly’, and ‘not difficult’.

Food security questions were not asked again until the COVID-19 surveys (COVID1 and COVID2) in 2020, where the cohort members (G1), the cohort members’ partners, the mothers/carers (G0), and partners/fathers (G0) were all asked about worries obtaining food.

In 2022, in the COVID6 survey, cohort members (G1), mothers/carers (G0), and partners/fathers (G0) were asked whether they had difficulties affording food during the COVID-19 pandemic.

Later, in the age 30– years survey, cohort members were asked if they were worried about experiencing difficulties paying for food, and the 2023 parents (G0) survey included the same question for the mothers/carers and partners/fathers.  

Other diet-related questions have been asked across the ALSPAC surveys, including infant feeding behaviours (ages 4 weeks, 6 months, 15 months), food attitudes (age 8/9 years), food preferences (age 25 years), COVID-impacted eating habits (age 27 and 28 years), and dairy/meat eating (age 29 and 20 years).  

Eating habits have been captured throughout childhood at ages 2, 3, 4, 6/7, 8/9, and 12/13 years. These questions have asked about over–, under–, and “picky” eating, what meals the child (or parent) eats in a day, frequency of eating fast food or takeaways, and the following of specific diets.

In adulthood, the eating habits questions were asked in the COVID-19 surveys, and captured information about meals eaten throughout the day, whether food eaten was made or bought, and the frequency of eating fast food and snacks.