ALSPAC: key findings

One of the strengths of ALSPAC is its ability to capture maternal diet during pregnancy.

Results from papers analysing maternal diet from FFQs in ALSPAC found that median intakes were above the recommended nutrient intakes for the majority of nutrients but not for iron, magnesium, potassium or folate and that not many women took supplements [95].

Since folate is an important nutrient to prevent neural tube defects, this finding strengthens the argument for fortification of stable foods with folate.

Five dietary patterns (DP) were described in this sample of women using PCA:

1. ‘Health conscious’ characterised by high consumption of salad, fruit, rice, pasta, breakfast cereals, fish, eggs pulses and non-white bread.
2. ‘Traditional British’ characterised by high consumption of all vegetables, meat and poultry.
3. ‘Processed’ high consumption of high-fat processed foods.
4. ‘Confectionery’ high consumption of snack foods and high sugar content.
5. ‘Vegetarian’ high consumption of meat substitutes, pulses, nuts and herbal tea [109].

These DPs were socially patterned e.g. higher consumption of a health conscious DP was associated with higher education and older age [109].

The effects of maternal diet during pregnancy on their children’s health was assessed in a number of papers. For example, higher maternal fish consumption during pregnancy was associated with higher verbal IQ at 6 to 8 months as well as higher development scores between 15 and 18 months [110, 111].

These papers concluded that the benefits outweigh the risks of fish consumption during pregnancy (e.g. there was no indication of fish consumption being associated with high total mercury concentrations).

When the children were 4 years old, the mother’s partners’ (men only) DPs were similar to the DPs identified during pregnancy:

1. ‘health conscious’
2. ‘traditional’
3. ‘processed/confectionery’
4. ‘semi-vegetarian’” [112].

As with the women, there were strong associations between these DPs and sociodemographic variables [112].

Diet in infancy has been described [105, 113]. DPs of the children at age 3, 4, 7 and 9 years have also been described [114-116].

Three main DPs were identified at each of these childhood ages:

1. ‘processed/junk food’
2. ‘health conscious’
3. ‘traditional British’.

These DPs were socially patterned and while similar patterns were identified at each childhood point, stronger periods of change were apparent between ages 3 and 4 and 7 and 9 years.

DPs in adolescents were also described by combining FFQ information from both the parents and the child:

1. ‘traditional/health conscious’
2. ‘processed’
3. ‘snacks/sugary drink’
4. ‘vegetarian”’.

There were clear sociodemographic differences. It was also noted that capturing dietary intake among adolescences is a difficult task and that using sources from both the parents and children themselves increased accuracy [117].

ALSPAC has collected diet longitudinally over the first 13 years of the study child’s life and has the ability to assess dietary change.

The stability over time was assessed by obtaining dietary patterns using cluster analysis of three diet diaries kept for the same children at ages 7, 10, and 13 years [118]. A healthy cluster was identified and was the most stable pattern, with half of the children starting in that cluster remaining in it at all three ages.

A processed cluster was the next most stable, with approximately 40% retained. This suggests that children introduced to either of these types of dietary pattern by 7 years of age are likely to continue with this pattern into adolescence.

A strength of the dietary data in ALSPAC children is the fact that they capture school lunches in the context of overall dietary intake which can support public health guidelines.

While the nutrient composition of both school dinners and packed lunches were below dietary guidelines, children eating packed lunches had poorer nutrient intakes overall than those eating school dinners [119].

Using the three-day diet diary data collected at ages 7, 10, and 13-years, a couple of papers have calculated the frequency of consumption of ultra-processed foods (UPFs) [102, 103].

After the diary data was coded using the Diet In, Data Out (DIDO) computer program and linked to food composition tables, the food and beverages were classified based on the NOVA food classification system, which classifies foods based on the extent and purpose of industrial processing [120].

This produced four food groups:

1. unprocessed/minimally processed
2. processed culinary ingredients
3. processed foods
4. UPFs.

These studies found that children eating the most UPFs, when compared to those eating the least, had increasing trajectories of BMI, fat mass index, weight, and waist circumference over 10-years follow-up [102].

A higher UPF consumption at age 7-years was also associated with deviation in multiple metabolic traits by age 17-years, many of which are associated with fat mass accumulation and child obesity risk [103].