1. Omega-3 fatty acids in childhood diets

Provision of a balanced diet is important in relation to the growth and development of children. Some specific aspects of diet have been shown to relate to cognitive development: for example, the consumption of oily fish in pregnancy was associated with better eyesight in 3-year olds (Williams et al 2001) and better cognition in 7-year olds in ALSPAC (Hibbeln et al 2007). The possible active factor in fish is its high content of omega-3 fatty acids.

Diet diary information was collected on the children at age 3 and age 7 by ALSPAC and this has been evaluated for nutrient and energy content. However the diary could also provide information on omega-3 and omega-6 fatty acids if the nutrient database was extended to cover these nutrients.

This project will entail working to extend the database to cover omega-3 and omega-6 fatty acids in all foods eaten at 3 and 7 years. Then combining this data with the information already available on these children to assess their intake of these nutrients. Outcomes, measured in ALSPAC, would then be investigated in the light of the intake of these fatty acids by the children.

This would provide a self-contained project with a data collection and handling element and a statistical and nutritional analysis element. The student would acquire practical skills in Nutritional Epidemiology that would be extremely beneficial to future work. These skills would include the use of international tables of nutrient content of foods, the assessment of misreporting and the handling of energy adjustment in dietary datasets. The latter two are very important issues that are difficult to deal with and have important affects on the meaningful interpretation of results in the field of nutrition.

2. Early nutrition

Correct feeding practices are important in relation to the growth and development of infants. When feeding formula the infant has less control over intake than when being breast fed as illustrated by a study from ALSPAC of infant diets at 4 months in relation to growth [Ong 2006]. Another European wide study has found that formula was often incorrectly made up by parents (CHOP personal communication) with possible consequences for obesity development.

Diet diary information was collected on 900 infants aged 4 months by ALSPAC. At the same time mothers were asked how they made up the formula in terms of number of scoops of powder used. This data needs to be extracted from the records. It could then be used in conjunction with the diet diary information already available and the records of growth in these children to investigate the affect of incorrect procedures on outcome.

This would provide a self-contained project with a data collection and handling part and a statistical and nutritional analysis part. A project report would be prepared with a possibility of submission for publication in a peer-reviewed journal at a later date.

3. Adolescent nutrition

The period of adolescence is a critical for the growth and development of an individual. It is also a time when children may take control of their diet from their parents and make important decisions about what foods they eat. This may impact on their growth with some tending towards obesity and other cutting down on particular foods e.g. avoiding dairy products or becoming vegetarian or cutting out many foods and becoming anorexic. Thus it is an important time to study the diet and nutrition of children.

Food frequency questionnaires were completed by children and their parents, in ALSPAC, when the children were aged 12 years. These have not yet been analysed. This data needs to be prepared for analysis using nutritional information about foods likely to have been eaten and portion sizes appropriate to 12-year-old children. Nutrient intakes can then be calculated and linked to outcomes such as low or high weight.

This project would give direct experience of how to analyse food frequency data, the handling of large datasets, the use of statistical packages and simple statistical analysis. A project report would be prepared that would input into further research.

ALSPAC website: http://www.bristol.ac.uk/alspac/

Emmett P. Dietary assessment in the Avon Longitudinal Study of Parents and Children. European Journal of Clinical Nutrition. 2009;63:S38-S44

Ong KK, Emmett PM, Noble S, Ness A, Dunger D, ALSPAC Study Team. Dietary energy intake at the age of 4 months predicts postnatal weight gain and childhood body mass index. Pediatrics 2006; 117:e503-508.