Agriculture, Life & Environmental Sciences-Agricultural, Food & Nutritional Science
University of Alberta
Summary of research:
The overall purpose of this study is to further understand factors affecting energy balance and energy metabolism of women in their postpartum period using a Whole Body Calorimetry Unit (WBCU). Rationale: Maternal body weight is an indicator of health of a mother and her developing fetus. While gaining too little weight is associated with low birth weight and preterm birth, excess weight gain in pregnancy contributes to increased rates of maternal and perinatal complications. The combination of excess weight gain in pregnancy and poor diet quality, followed by less than recommended postpartum weight loss, makes “pregnancy” a major risk factor for obesity and related chronic diseases. Research: Sixty (60) women who are less than 3 months postpartum will be recruited to participate at 3 and 9 months postpartum in the calorimetry assessment study. Physiological measures hypothesized to be associated with weight loss or retention will be measured at that time. These include body mass index (BMI), body composition, waist circumference, biochemical measures, fitness level, blood pressure, resting heart rate. A 1.5hr resting energy expenditure (EE) and 24hr EE will be measured by indirect calorimetry in a live-in WBCU at 3 and 9 months postpartum respectively. Output data from the WBCU includes resting metabolic rate, thermic effect of food, exercise energy expenditure, sleep energy expenditure and utilization of fat and carbohydrate. Biochemical measures that will be taken during fasting and two hours postprandial include: glucose, insulin, free fatty acids, triglycerides, leptin, ghrelin, (peptide YY) PYY and prolactin. Behavioural factors such as dietary intake (3 day food records), physical activity (Baecke and STARQ questionnaires), breastfeeding practices and sleep patterns (PSQI questionnaire) will also be assessed to determine the relationship with postpartum weight loss or retention. General health and mental health (EPDS questionnaire) as well as demographic information will also be collected.