Dietary intake and adherence to dietary guidelines and nutrient recommendations among New Zealand pregnant women : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Nutrition and Dietetics at Massey University, Albany, New Zealand

Abstract

National dietary guidelines are created to support maternal and fetal health during pregnancy, when nutrient requirements increase for both the mother and the baby. This study aimed to assess the adherence to the 2020 New Zealand Eating and Activity Guidelines (EAG) for pregnant women and selected Nutrient Reference Values (NRVs) for Australia and New Zealand across pregnancy. This study is a secondary analysis of data from the Koru Study, a longitudinal observational study conducted in New Zealand between 2019 and 2022. Healthy pregnant women aged 18–45 years (n = 23) with naturally conceived singleton pregnancies were recruited for this study. Participants completed a 4-day diet diary at up to 3 time points (trimesters 1, 2, and 3) to estimate daily food group servings and nutrient intakes. The current study found that the overall adherence to food group recommendations was low. More than half of participants (52%) met only one to two food group recommendations, while 45% met none; no participant met all five food group guidelines. Adherence was lowest for grain foods and fruit, with fewer than 10% meeting recommendations. Vegetable intake was suboptimal, with fewer than 1 in 5 participants meeting the guideline. Adherence to milk and milk products was the highest among food groups, although fewer than one in five women met the recommended Intake. Protein-rich food recommendations were met by 16.7% of participants. The macronutrient distribution showed high adherence to the Acceptable Macronutrient Distribution Range (AMDR) for protein (73.8%. Moderate adherence was seen for carbohydrate (50%), and very low adherence for total fat (4.8%) and saturated fat (14.3%). Adequate fibre intake was achieved by 40.5% of participants. The mean protein intake exceeded the EAR of 49 g/day across all trimesters, with mean intake of 89.5 g/day in Trimester 1, 92.5 g/day in Trimester 2, and 78.8 g/day in Trimester 3, suggesting that most women were likely to have met the protein requirement. The majority of participants did not meet the EAR for iodine (76.2%) or iron (90.5%), or the Adequate Intake for vitamin D (73.8%) or folate (59.5%). Vitamin C showed the highest overall adherence (88.1%). Significant positive correlations were observed between milk and milk product intake and calcium intake (ρ = 0.683, p < 0.001). There was a positive association found between fruit intake and fibre intake (ρ = 0.402, p = 0.008) and vitamin C intake (ρ = 0.351, p = 0.022). Vegetable intake is positively associated with fibre intake (ρ = 0.535, p = <0.001), folate intake (ρ= 0.44, p = 0.004), iron intake (ρ= 0.392, p = 0.010), and iodine intake (ρ = 0.327, p = 0.035). Protein-rich food intake was positively associated with total protein intake (ρ = 0.593, p = <0.001), selenium intake (ρ = 0.354, p = 0.021), and iodine (ρ= 0.369, p = 0.016). In this current study, the adherence to food group recommendations during pregnancy was suboptimal, with multiple micronutrient inadequacies.