Dietary intakes assessed by 24-h recalls in peri-urban African adolescents: validity of energy intake compared with estimated energy expenditure.

BACKGROUND/OBJECTIVE: The objective of this study is to determine the relative validity of reported energy intake (EI) derived from multiple 24-h recalls against estimated energy expenditure (EE(est)). Basal metabolic rate (BMR) equations and physical activity factors were incorporated to calculate EE(est). SUBJECTS/METHODS: This analysis was nested in the multidisciplinary PhysicaL Activity in the Young study with a prospective study design. Peri-urban black South African adolescents were investigated in a subsample of 131 learners (87 girls and 44 boys) from the parent study sample of 369 (211 girls and 158 boys) who had all measurements taken. Pearson correlation coefficients and Bland-Altman plots were calculated to identify the most accurate published equations to estimate BMR (P<0.05 statistically significant). EE(est) was estimated using BMR equations and estimated physical activity factors derived from Previous Day Physical Activity Recall questionnaires. After calculation of EE(est), the relative validity of reported energy intake (EI(rep)) derived from multiple 24-h recalls was tested for three data subsets using Pearson correlation coefficients. Goldberg's formula identified cut points (CPs) for under and over reporting of EI. RESULTS: Pearson correlation coefficients between calculated BMRs ranged from 0.97 to 0.99. Bland-Altman analyses showed acceptable agreement (two equations for each gender). One equation for each gender was used to calculate EE(est). Pearson correlation coefficients between EI(rep) and EE(est) for three data sets were weak, indicating poor agreement. CPs for physical activity groups showed under reporting in 87% boys and 95% girls. CONCLUSION: The 24-h recalls measured at five measurements over 2 years offered poor validity between EI(rep) and EE(est).

Risk Factors of Poor Anthropometric Status in Children Under Five Years of Age Living In Rural Districts of the Eastern Cape and Kwazulu-Natal Provinces; South Africa

Objectives: Factors associated with children's anthropometric status were determined. Design: Secondary analysis was done using data from a cross-sectional survey including children under five years of age (n = 2 485) and their mothers in rural districts of the Eastern Cape and KwaZulu-Natal provinces; South Africa. Methods: Data generated by questionnaire and anthropometric indices were used to construct a logistic regression model; taking into account hierarchical relationships of risk factors to determine the odds of a child being stunted; underweight or overweight. Statistical significance was set at p 0.05. Results: Factors associated with stunting were child of male gender (odds ratio (OR)

Risk Factors of Poor Anthropometric Status in Children Under Five Years of Age Living In Rural Districts of the Eastern Cape and Kwazulu-Natal Provinces; South Africa

Objectives: Factors associated with children's anthropometric status were determined. Design: Secondary analysis was done using data from a cross-sectional survey including children under five years of age (n = 2 485) and their mothers in rural districts of the Eastern Cape and KwaZulu-Natal provinces; South Africa. Methods: Data generated by questionnaire and anthropometric indices were used to construct a logistic regression model; taking into account hierarchical relationships of risk factors to determine the odds of a child being stunted; underweight or overweight. Statistical significance was set at p 0.05. Results: Factors associated with stunting were child of male gender (odds ratio (OR)

Substitution of high monounsaturated fatty acid avocado for mixed dietary fats during an energy-restricted diet: effects on weight loss, serum lipids, fibrinogen, and vascular function.

OBJECTIVE: First, we wanted to dispel the myth that avocados are fattening and therefore should be avoided in energy-restricted diets. Second, we examined the effects of avocados, a rich source of monounsaturated fatty acids, as part of an energy-restricted diet on weight loss, serum lipids, fibrinogen, and vascular function in overweight and obese subjects. METHODS: Sixty-one free-living volunteers (13 men and 48 women), with body mass index of 32 +/- 3.9 kg/m(2) (mean +/- standard deviation) participated in this randomized, controlled, parallel study. Subjects were paired and randomly assigned to one of two groups. The experimental group consumed 200 g/d of avocado (30.6 g of fat), which substituted for 30 g of other mixed dietary fats such as margarine or oil, and the control group excluded avocado from their energy-restricted diet for 6 wk. Seven-day isoenergetic menus were planned according to mean energy requirements of both sexes to provide total energy intakes consisting of 30% fat, 55% carbohydrates, and 15% protein. Anthropometric measurements, physical activity, blood pressure, and arterial compliance were measured with standard methods at the beginning and end of the intervention. Fasting blood samples were drawn at the beginning and end of the intervention. RESULTS: Fifty-five subjects completed the study. The compliance rate to avocado intake in the experimental group was 94.6%. The percentage of plasma oleic acid increased significantly with the consumption of avocado in the experimental group, whereas a decrease was seen in the percentage of myristic acid from baseline to the end of the intervention in both groups but was significant only in the experimental group. Anthropometric measurements (body mass, body mass index, and percentage of body fat) decreased significantly in both groups during the study (P < 0.001), and the change was similar in both groups. Serum lipid concentrations (total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triacylglycerols), fibrinogen, blood pressure, and arterial compliance did not change significantly within or between groups. CONCLUSION: The consumption of 200 g/d of avocado within an energy-restricted diet does not compromise weight loss when substituted for 30 g of mixed dietary fat. Serum lipid concentrations, plasma fibrinogen, arterial compliance, and systolic and diastolic blood pressures were not affected by weight loss or avocado intake.