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BCS70: dietary data collection

Dietary data collection

Information about dietary intake was collected during the birth survey and at ages 10 (1980), 16 (1986), 30 (2000), 42 (2012), 46 (2016), 50 (2020) and 51 years (2021) using different methods.

A summary of the different diet-related questions asked at each time point are outlined in the sections and table below.

Diet-related questions in BCS70

1970 1980 1986 1999-2000 2012 2016 2020 2020 2020 2021
Sweep 1 Sweep 3 Sweep 4 Sweep 6 Sweep 9 Sweep 10 COVID1 COVID2 COVID3 Sweep 11
Age 0y Age 10y Age 16y Age 29-30y Age 42y Age 46y Age 50y Age 50y Age 50y Age 51y
Respondent (CM = cohort member; M = mother) M CM CM CM CM CM CM CM CM CM
Questionnaire source** PAPI SC SC***, DD CAPI SC Online DD†† CAWI CAWI CAWI Online DD††
4-day diet-diary
Online diet-diary
24-hour recall**
Type of feeding on Day 1 – Day 7 (e.g. breastmilk, formula etc.)
Frequency of types of food:
Frequency of fresh fruit
Frequency of salad/raw vegetables
Frequency of cooked vegetables
Frequency of white bread
Frequency of brown bread
Frequency of wholemeal/granary bread
Frequency of wholemeal bread or rolls
Frequency of other bread or rolls
Frequency of breakfast cereal
Frequency of butter
Frequency of margarine
Frequency of cheese
Frequency of eggs
Frequency of pulses
Frequency of meat
Frequency of red meat
Frequency of chicken or turkey
Frequency of poultry
Frequency of fish
Frequency of chips
Frequency of food fried in vegetable oil
Frequency of food fried in hard fat
Frequency of chocolate/sweets
Frequency of sweets
Frequency of chocolate
Frequency of puddings
Frequency of biscuits and cakes of all kinds
Frequency of cakes or buns
Frequency of sweet biscuits
Frequency of crisps
Cups/glasses tea
Frequency of tea
Cups/glasses cocoa
Frequency of cocoa
Cups/glasses coffee
Cups/glasses milk
Frequency of milk
Cups/glasses cola
Frequency of cola
Frequency of low calorie or sugar free drinks
Frequency of fresh fruit juice
Frequency of fruit squash
Cups/glasses water
Frequency of water
Frequency of takeaways
Frequency of home-cooked meal
Frequency of ready meals
Frequency of other convenience foods
Type of lunch yesterday
Type of breakfast yesterday
Number of days consuming breakfast
How much milk sugar and sweetener you add to tea or coffee
Are you a vegetarian/special diet
Number of times per week you get food from takeaway
In month prior to COVID outbreak, how many portions of fresh fruit and vegetables consumed per day
Post-COVID outbreak/last 4 weeks, how many portions of fresh fruit and vegetables consumed per day
Food security, use of food banks

* Hyperlinks provided to the BCS70 sweep information pages. 

**Hyperlinks provided to the dataset/questionnaire on CLOSER Discovery (where available), or other information pages. PAPI = Paper Assisted Personal Interview; CAPI = Computer Assisted Personal Interview; CAWI = Computer Assisted Web Interview; SC = self-completion questionnaire; DD = Diet Diary 

*** Multiple self-completion questionnaires used in sweep 4: Student Test Booklet (Document B) & Student Score Form (Document C); Health-Related Behaviour Student Self-Completion Questionnaire (Document F); ‘Home and All That’ Student Self-completion Questionnaire (Document G). 

†† information about the Oxford WebQ is available here: https://www.ceu.ox.ac.uk/research/oxford-webq.
More detailed information about the questions and format of the diary are available here: https://biobank.ctsu.ox.ac.uk/crystal/crystal/docs/DietWebQ.pdf   

Response options for frequency of consumption:
– Sweep 3 (1980, age 10 years) = nearly every day, quite often, sometimes, and hardly ever. 
– Sweep 4 (1986, age 16 years) = ranged from zero to seven times per weekA separate ‘soft drinks’ section assessed the consumption of drinks with a variety of responses.
– Sweep 6 (1999-2000, age 29-30 years) = more than one per day, one per day, 3-6 days per week, 1-2 days per week, less than one day a week, occasionally, never.
– Sweep 9 (2012, age 42 years) = one per day, one per day, several times a week, once or twice a week, at least once a month, less often, never. 

Recall asked about specific items including amounts of: meat, fish, eggs/cheese, milk, tea/coffee, cereal, bread, soup, potatoes, baked beans, rice/spaghetti, packets of crisps, ice lollies, ice cream, mousse, sweets, chocolate biscuits of bars, biscuits, cakes or tarts, fruit pies, puddings, squash or cordial, fizzy drinks, fruit juice, fresh fruit, raw vegetables or salads, cooked vegetables (not potatoes), alcoholic drinks, other items. 

Over counter in school/packed lunch in school/outside school takeaway/outside school packed lunch/at home/did not have lunch. 

Nothing, just something to drink, cereal or bread and drink, cereal and bread and drink, just an egg and drink, cooked breakfast with bread and drink, cooked breakfast with cereal and bread and drink. 

Next page: BCS70: estimation of nutrient intake