Dietary data in the 1958 National Child Development Study

Learn about the National Child Development Study (NCDS) and its dietary measurements

Summary of cohort
Dietary data collection
Response
Key findings

Summary of cohort

The National Child Development Study (NCDS), also known as the 1958 British birth cohort study, is an on-going, multidisciplinary study. NCDS is the second oldest nationwide birth cohort after the 1946 British birth cohort study (National Survey of Health and Development, NSHD). The aim of NCDS is to monitor social, behavioural, educational and physical outcomes as well as to collect information regarding economic circumstances, employment and health behaviour [56]. The NCDS began as the Perinatal Mortality Study to investigate still-birth and infant mortality. Mothers of babies born in one week in March 1958 in England, Scotland and Wales (approximately 17,415) were interviewed by midwives, who completed questionnaires with reference to medical records [57]. During the childhood sweeps, immigrants that were born during the survey week in March 1958 were added to the study (n=~800) [58]. To date, the cohort has been followed up ten times; at ages 7, 11, 16, 23, 33, 42, 46, 50, and 55 years including a biomedical survey at 45 years.

As with all cohort studies, sample attrition has occurred in NCDS. For example, those with a lower socioeconomic position (SEP) at birth, lower mathematics score and with internalising and externalising behaviours at 7 years were found to be under-represented in the 45 year survey [59]. Although immigrants were included during the childhood studies, the majority of participants of the NCDS are from a white European population [59]. Participants of the 45 year biomedical survey were shown to broadly represent those born in Britain in 1958 and resemble the white British population [59].

Dietary data collection

Information about dietary intake was collected at ages 33 (1991) and 42 (2000), as well as at the biomedical sweep at 45 years (2003). While no established DAT was used, the frequency of consumption of a limited number of specific foods was recorded and these foods varied across sweeps (see the table below).

It is noteworthy that in 1991 the questions for fresh fruit and salad or raw vegetables were season-specific, but in 2000 they were not. Participants were also asked if they followed a special diet.

Diet-related questions in NCDS

	1991	2000	2003
	Age 33y	Age 42y	Age 45y
Questionnaire source*	Questionnaire	Questionnaire	Questionnaire
Fresh fruit in summer	✔
Fresh fruit		✔
Salads or raw vegetables in winter	✔
Salads or raw vegetables		✔
Cooked vegetables		✔
Eggs		✔
Chips	✔	✔
Sweets or chocolates	✔	✔
Biscuits	✔
Biscuits and cakes		✔
Fried food not counting chips	✔
Food fried in vegetable oil such as sunflower oil, not counting chips		✔
Food fried in hard fat such as lard or butter, not counting chips		✔
Type of bread usually eaten**	✔
Wholemeal bread or rolls		✔
Other bread or rolls		✔
Red meat like beef, lamb or pork
Poultry like chicken or turkey		✔
Fish		✔
White fish (e.g. cold, plaice, halibut)			✔
Other fish (e.g. salmon, trout, mackerel, sardines, fresh tuna)			✔
Canned tuna fish			✔
Pulses such as baked beans and lentils		✔
Tea			✔
Coffee			✔
Milk alone or in milky drinks e.g. hot chocolate			✔
Milk on cereal			✔
Milk-based savoury dishes (e.g. quiche, cheese or white sauce)			✔
Milk-based desserts (e.g. custard, ice-cream, rice pudding)			✔
Hard cheeses			✔
Sort cheeses			✔
Margarine on bread or equivalent			✔
Butter on bread or equivalents			✔
Type of milk usually consumed†			✔
On a special diet?		✔

Notes.
* Link provided to CLOSER Discovery (interactive version) or original study PDF as applicable.
** White bread, wholemeal bread, other brown bread, crispbreads, white pitta bread, wholemeal pitta bread, nan/chapattis, other bread, no bread.
† Whole, semi-skimmed, skimmed, soya, goats, sheep, other, and none.

Response options.
In 1991, there were six possible responses: more than once a day, once a day, 3-6 days per week, 1-2 days per week, less than one day per week, never.
In 2000, there were seven possible responses: more than once a day, once a day, 3-6 days a week, 1-2 days a week, less than one day per week, occasionally, never.
In 2003, there were eight possible responses: more than four times a day, 2-4 times a day, once a day, 3-6 days a week, 1-2 days a week, less than one day per week, occasionally, never.

Response

Response to dietary measures in NCDS

Original cohort consisted of 17415 participants.

Year	Age (y)	N interviewed	Response to diet question* (n(%))
1991	33	11,469	11,372 (99%)
2000	42	11,419	11,373 (99%)
2003	45	9,377	9,181 (98%)

Notes.
* Response based on answering at least one of the questions from the dietary questions listed above.

Key findings

Dietary trends and dietary patterns in adulthood

Two studies examined trends in food consumption over this 9 year period between 1991 (33 years) and 2000 (42 years) [60, 61]. For both men and women, dietary habits were slow to change [60, 61]. At 33 years, there was evidence that higher educational attainment was associated with consuming fruit, salad or raw vegetables more frequently and chips and fried food less frequently compared with lower attainment [60]. Parsons et al. created a dietary quality score using these data [61]. Briefly, the authors treated fruit and salad as ‘healthy’ foods with consumption frequencies classified from 1 (least frequent) to 5 (most frequent). Chips, sweets, biscuits and fried food were classified as ‘unhealthy’ foods with consumption coded in reverse from 5 (least frequent) to 1 (most frequent) so that a higher value indicates better diet quality. As assessed by this measure, overall improvement in diet quality between 33 and 42 years was found to be very small [61].

One study compared dietary intake between NCDS and the 1970 British birth cohort which is discussed here.

Learn about the other studies covered by this guide and their dietary measurements:

Get background detail on this guide:

Learn about harmonisation in the context of dietary data:

Discussion & illustration of dietary data harmonisation

Further information:

This page is part of the CLOSER resource: ‘A guide to the dietary data in eight CLOSER studies’.