Ethical matters

Many ethical principles were taken into account, including (but not limited to) respect for persons, minimisation of harm, informed and voluntary consent, respect for privacy and confidentiality, avoidance of conflict of interest, social and cultural sensitivity, and justice. Examples are given, as follows:

Before commencing data collection (section 3.5.2), participants were provided with an information sheet on the study and encouraged to ask questions for clarification. Afterwards,

they were invited to give written consent for participating in the study. Participants were also reminded they could withdraw from the study at any time, with no consequences of any kind.

To protect the privacy of participants, they were assigned unique number identifiers, rather than names, addresses, or other information which could be traced back to them. Data was kept in locked cabinets and computer files were protected by passwords. Researchers were only issued data they specifically needed for their study, attached to the unique number identifiers.

Cultural sensitivity was expressed when researchers asked participants if they were able to touch their head for height measurements, using a Stadiometer. The head is tapu (sacred) to Māori people, so it is respectful to ask for permission. Sensitivity was also expressed regarding body image, where separate rooms were provided for participants to have privacy when removing items of clothing, for procedures such as BodPod measurements. This requires minimal clothing, to reduce error caused by the trapped air.

Afterwards, participants were entitled to information obtained about themselves, such as their BF percentage. Participants can then be assessed and, if necessary, treated by health

professionals, should they choose to disclose their body composition and/or dietary data.

3.4 Participants

All of the Māori (n=84) Pacific (n=91) participants from the women’s EXPLORE study were included in this sub-study. Power calculations from the women’s EXPLORE study found that the sample sizes were sufficient to provide 80% power at significance levels of p <0.05 (Kruger et al., 2015). Participants were recruited from Massey University’s Albany Campus and

throughout Auckland via researchers’ friends, colleagues, clubs, groups and various other organisations. Recruitment included communication through telephone calls, emails,

pamphlets, and face-to-face interactions. Following recruitment, participants were prompted to complete an online screening questionnaire. The questionnaire determined eligibility, based on specific inclusion and exclusion criteria. Included, were women who were healthy, post- menarcheal and pre-menopausal, between 16-45 years old, living in Auckland, NZ. Exclusion criteria included women who were pregnant, lactating, trying to lose/gain weight, and

diagnosed with chronic disease or illness, especially illness of metabolic consequence (e.g. type 2 diabetes mellitus). Those eligible, according to the online screening questionnaire, were invited to participate in on-site screening (Section 3.5.1). Following on-site screening was data collection, as explained in Section 3.5.2 below.

74 3.5.1 Screening

Simple anthropometric measures were taken from recruited participants, at Massey

University’s Albany Campus, in the Human Nutrition Research Unit. Trained research assistants measured participant height with a Stadiometer, using international standards for

anthropometric assessment (Marfell-Jones, Stewart, & de Ridder, 2006). Following, they measured participant weight with a bioelectrical impedance analysis scale (Biospace, Inbody 230, Cerritos, CA, USA). Lastly, body mass index (BMI) was calculated using the following equation: weight (kg)/ height (cm)2.

3.5.2 Data collection

Participants arrived at Massey Human Nutrition Research Unit between 7am and 9:45am, to complete consent forms, health questionnaires, and approximately two hours’ worth of tests. For purposes of this sub-study, the following anthropometric and dietary data was used: weight, height, WC, hip circumference, BF percentage (from air displacement plethysmography air displacement plethysmography) and the type / amount / frequency of food intake over the past month.

3.5.2.1 Anthropometric measurements

Trained researchers, using International standards for anthropometric assessment protocol (Marfell-Jones et al. 2006), obtained the anthropometric results: weight, height, waist circumference, hip circumference, and BF percentage. BF percentage was measured using an air displacement plethysmography (ADP) machine, the BodPod (2007A, Life Measurement Inc, Concord, Ca., using software V4.2+ as supplied by the manufacturer). ADP is a more

sophisticated, reliable and valid method of assessing BF percentage compared with BIA (Noreen & Lemon, 2006; Wingfield et al., 2014). Yet it requires multiple preliminary

procedures: no drinking, eating or exercising two hours prior to assessment, an empty bladder, only tightly-fitted clothing, and removal of any metal (e.g. jewellery). Wearing tight-fitted clothing and a swimming cap minimised errors in body volume, which would be caused by air trapped in clothing and hair. Furthermore, lung volume was calculated by measuring the airway and chamber pressures, as the participant breathed into a disposable tube. 3.5.2.2 Dietary assessment

Participants completed the validated, 220-item, self-administered, semi-quantitative NZ women’s food frequency questionnaire (NZWFFQ) (Houston, 2015) (See Appendix 1) online, at

the Massey Human Nutrition Research Unit. The FFQ was validated on Māori and Pacific women, 16-45 years, living in Auckland, NZ. The NZWFFQ assesses participant dietary intake over the previous month and has been adapted from the 1997/98 NZANS (Houston, 2015). Included, are typical NZ foods as well as traditional Māori and Pacific foods, such as Rewena bread and taro, respectively. With each food, participants chose a frequency ranging from “Never” to “4+/day”, or to “7+/day”. Amounts of food were based on standard serving equivalents (SSE), for analysis. SSE are needed because portion sizes can vary between individuals and on a day-to-day basis, but serves are consistent and measured amounts of particular foods (Daggett & Rigdon, 2006). SSE of foods are outlined in the EAGNZA (MOH, 2015b). Where SSE were not defined in the EAGNZA, SSE sizes were sourced from Australian Dietary Guidelines (AGDH, 2015). For decisions regarding SSE, refer to Appendix 2.

76 3.5 Procedures

Identify BMI and BF percentage groups

High BMI (≥25 kg/m2) Normal BF (22-30%) Less fat 2 Normal BMI (18.5-25 kg/m2) Normal BF (22-30%) Normal fat Stage 1 Māori Women: 16 – 45 years Post-menarcheal; Pre-menopausal n=84 Pacific n=91 Screening x Health screen

x Body composition Height and weight

Stage 2

Visit Human Nutrition Research Unit

Body fat Dietary intake

x Anthropometric

measurements

x ADP (BodPod)

Dietary questionnaire:

x FFQ

Figure 3.1 Study design and procedures.

Māori, n=79 Pacific, n=75 Participants after exclusion

Normal BMI (18.5-25 kg/m2) High BF (≥30%) Hidden fat Normal BMI (18.5-25 kg/m2) Low BF (<22%) Less fat 1 High BMI (≥25 kg/m2) High BF (≥30%) Apparent fat High BMI (≥25 kg/m2) Low BF (<22%) Low fat

3.6 Data processing

3.6.1 Dietary assessment software

Questionnaire data was processed in FoodWorks 8, 2015 (Xyris Software (Australia) Pty Ltd, Queensland, Australia), which utilises NZ FOODfiles 2014 (developed by the NZ Institute for Plant & Food Research and the NZ MOH) as the reference food composition database (FoodWorks Professional, 2016). Researchers cross-checked data within FoodWorks, to help increase accuracy. Afterwards, data was extracted from FoodWorks 8 and converted to daily equivalent frequencies (Table 3.1).

Table 3.1 Processing extracted food frequencies, for data analysis

Frequency (most food) Average frequency Daily frequency

Never 0m 0.00 <1x/month 0.25m 0.01 1-3x/month 2m 0.07 1x/week 1w 0.14 2-3x/week 2.5w 0.36 4-6x/week 5w 0.71 Once/day 1d 1.00 2-3x/day 2.5d 2.50 ≥4x/day 4d 4.00

Frequency (Butter, Margarine or Spreads) Average frequency Daily frequency

Not applicable 0d 0.00 <1x/day 0.25d 0.25 1-2x/day 1.5d 1.50 3-4x/day 3.5d 3.5 5-6x/day 5.5d 5.5 ≥7/day 7d 7

Frequency (Fats and Oils used for Cooking) Average frequency Daily frequency

Not applicable 0w 0.00 <1x/week 0.25d 0.07 1-3x/week 1.5w 0.21 4-7x/week 5.5w 0.79 8-10x/week 9w 1.29 11-14x/week 12.5w 1.79 ≥15/week 15w 2.14

Frequency (Protein supplements) Average frequency Daily frequency

3x/week 3w 0.43 4x/week 4w 0.57 Other 0.5d 0.5 2w 0.29 7.5w 1.07

78