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 week. A 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.