Accuracy of Reporting Food Energy Intake: Influence of Ethnicity and Body Weight Status in South African Women

The current study sought to identify characteristics that may be associated with the misreporting of food energy intake (EI) in urban South African women. A total of 198 women (61 black; 76 of mixed ancestry; 61 white) completed a quantified food frequency questionnaire; from which daily energy and macronutrient intake were calculated. Body composition (body mass index [BMI]; percentage of body fat); body image (Feel-Ideal Difference index and Body Shape questions) and socio-economic status (SES) (household density and asset index) were also measured. Food EI in relation to estimated basal metabolic rate ratio that was less than 1.05 represented under-reporting; whereas a ratio greater than 2.28 represented over-reporting. Results suggested that 26of the participants under-reported; 64adequately reported and 10over-reported. Participants who under-reported had a higher BMI (p 0.01) and higher percentage of body fat (p 0.05) than those who adequately and over-reported. The majority of under-reporters were black (38) versus 21under-reporters of mixed ancestry and 20white under-reporters (p 0.01). Eighty-three per cent of black under-reporters were obese. On the other hand; a majority (63) of overweight women of mixed ancestry and a majority (50) of white normal-weight women under-reported their food EI. Under-reporters reported a lower intake of dietary fat (p 0.01) and a higher intake of dietary protein (p 0.01) than adequate or over-reporters. Food EI reporting was not influenced by SES or body image. In conclusion; results suggest that food EI reporting is influenced by body size; and may be ethnic-specific in South African women

Validity and Reliability of a Physical Activity/Inactivity Questionnaire in South African Primary Schoolgirls

Objective. We sought to determine the validity and reliability of a self-report physical activity questionnaire (PAQ) measuring physical activity/inactivity in South Africanschoolgirls of different ethnic origins. Methods. Construct validity of the PAQ was tested against physical activity energy expenditure estimated from an ACTIVITYGRAM and inactivity from reported television programme viewing in 332 girls (ages 9 - 12 yrs; grades 4 - 5). Body composition (WHO BMI percentiles and percentage body fat) was used as an indirect measure of validity for the PAQ. Test-retest reliability of the PAQ was assessed in a convenience sample of 14 girls. Results. Weak but significant associations were found between the body composition and PAQ-derived total energy expenditure (r=-0.18; p0.05 for percentage body fat; rschool sports showed good test-retest reliability (r=0.80; p0.05). Conclusions. Our results showed that the PAQ may provide some reasonable insights into levels of physical inactivity and activity in South African primary schoolgirls. However; additional studies are required using objective measures of physical activity; such as pedometry or accelerometry; to better understand the utility of the PAQ for children