Longitudinal assessment of energy expenditure in pregnancy by the doubly labeled water method

Abstract

Twelve women were studied before pregnancy and at 6-wk intervals from 6 to 36 wk gestation. Total energy expenditure (TEE) by the doubly labeled water method, basal metabolic rate (BMR), energy intake, and body composition were assessed on each occasion. There was substantial interindividual variation in the response to pregnancy. Mean total energy costs were as follows: delta BMR 112 +/- 104 MJ (range -53 to 273), delta TEE 243 +/- 279 MJ (range -61 to 869 MJ), and fat deposition 132 +/- 127 MJ (range -99 to 280 MJ). The mean total cost of pregnancy (cumulative TEE above baseline+energy deposited as fat and as products of conception) was 418 +/- 348 MJ (range 34-1192 MJ). This was much higher than current recommendations for incremental energy intakes. Self-recorded incremental intakes (208 +/- 272 MJ) seriously underestimated the additional costs. The variability in response emphasizes the problems in making prescriptive recommendations for individual women, because there is no way of predicting metabolic or behavioral responses to pregnancy.

Dietary restraint and weight gain during pregnancy

“…The validity of diet records is a particular concern when examining restrained individuals Dietary restraint and weight gain during pregnancy R Conway et al (Bingham et al, 1995). However, in the present study the energy intakeaBMR ratios do not suggest this was a particular problem, ratios were comparable with those reported by Goldberg et al (1993) who observed ratios between energy intake and measured BMR of between 1.22 and 1.40 at different stages of pregnancy. Pregnancy may be one of the few periods in life when women are more likely to honestly report what they are eating and decreased feeling of accountability for intake may also have some in¯uence.…”

Energy intake and expenditure of free-living, lactating Colombian women in an urban setting

“…For NPNL women, energy intake was significantly less than TDEE suggesting negative energy balance in this group. This finding is difficult to explain but, as Goldberg et al, (1993) have argued may be due simply to the uncertainty introduced by the real day-to-day variation in each variable.…”

Significant changes in physical activity among pregnant women in the UK as assessed by accelerometry and self-reported activity

“…The timing of the two observations, at 20 and 32 weeks, also differs from the present study. Goldberg et al (1993) reported a significant decline in physical activity from 30 to 36 weeks, but at no other time in pregnancy. However, the 12 women in the study were highly selected and activity of several participants was restricted by serious medical complications.…”

“…The enormous inter-and intraindividual variability in basal metabolic rate and heart rate during pregnancy means that repeated laboratory testing is required to assess physiologic and metabolic variables before assessing PAL and total energy expenditure (Goldberg et al, 1993). The complications presented by metabolic and physiologic changes during pregnancy mean that assessment of physical activity by either accelerometry or activity recall has certain advantages over the laboratory assessment of total energy expenditure.…”

“…Conventional techniques used within the general population include pedometry, accelerometry, heart rate monitoring and activity records obtained through diaries or recall (Westerkerp, 1999;Conway et al, 2002). Although doubly labelled water is now the gold standard for the assessment of energy expenditure, the costs associated with this method restrict its use in population studies (Goldberg et al, 1993).…”