Variations in resting energy expenditure: impact on gestational weight gain

Abstract

Background There are significant variations in gestational weight gain with many women gaining in excess of Institute of Medicine guidelines. Unfortunately, efforts to improve appropriate gestational weight gain have had only limited success. To date, interventions have focused primarily on decreasing energy intake and/or increasing physical activity. Maternal resting energy expenditure, which comprises ~60% of total energy expenditure compared with the ~20% that comes from physical activity, may be an important consideration in understanding variations in gestational weight gain. Objective Our objective was to quantify the changes in resting energy expenditure during pregnancy and their relationship to gestational weight gain and body composition changes among healthy women. We hypothesized that greater gestational weight gain, and fat mass accrual in particular, are inversely related to variations in resting energy expenditure. Study design We conducted a secondary analysis of a prospective cohort studied preconception and late (34–36 weeks) pregnancy. Body composition (estimated using air densitometry, BodPod) and resting energy expenditure (estimated using indirect calorimetry) were measured. The relationship between changes in resting energy expenditure and gestational weight gain, and change in fat mass and fat free mass were quantified. Resting energy expenditure was expressed as kilocalories per kilogram of fat free mass per day (kcal.kg FFM−.day−1) and kilocalories per day (kcal/day). Correlations are reported as r. Results Among 51 women, preconception body mass index was 23.0 (4.7) kg/m2; gestational weight gain was 12.8 (4.7) kg. Preconception and late pregnancy resting energy expenditure (kcal/day) correlated positively with the change in fat free mass (r=0.37, p=0.008; r=0.51, p=0.001). Late pregnancy resting energy expenditure (kcal.kg FFM−.day−1) was inversely associated with the change in fat mass (r=−0.34, p=0.02) and gestational weight gain (r=−0.29, p=0.04). From pre-pregnancy through late gestation, the increase in resting energy expenditure (kcal/day) correlated positively with the change in fat free mass (r=0.44, p=0.002), and negatively with the change in fat mass (r=−0.27, p=0.06). Conclusions The change in resting energy expenditure from preconception through late gestation correlated positively with changes in fat free mass but negatively with fat mass accrual. Women with smaller increases in resting energy expenditure across pregnancy had greater gestational weight gain, specifically more adipose tissue. These data suggest that resting energy expenditure is an important factor in gestational weight gain, particularly excess fat mass accrual. Future lifestyle intervention studies need to consider clinically feasible means of estimating resting energy expenditure and, in response, tailor nutrient intake and composition recommendations. Implementing and testing such interventions would be a novel approach to improve compliance with gestational weight gain guidelines.

Resting Energy Expenditure Relationship with Macronutrients and Gestational Weight Gain: A Pilot Study

“…The smaller increase in the current study could be explained by the shorter evaluation period. Unlike other studies that found a moderate negative correlation between REE in the 3rd trimester and total GWG [11], we only found a positive correlation between early changes in REE and GWG in the latter half of the study. Our lack of a positive association across the entire study period may be due to the small sample size or large variations in REE at each study visit.…”

“…In our study, there was an overall increase in REE throughout the study of 11.5%. This is similar to other studies that have assessed REE that found increases ranging from 13% to 35% [8,11,[15][16][17]. The large range in changes in REE throughout pregnancy is reflective of the population being studied, the body weight status prior to the study, and the duration of data collection (e.g., preconception to postpartum).…”

“…Previous research has demonstrated that greater increases in GWG are associated with decreased physical activity, increased energy intake, higher pre-pregnancy BMI, race/ethnicity, and maternal education [5,6]. Recently, research has focused on the evaluation of resting energy expenditure (REE) across pregnancy to better account for the physiological variability in metabolic adaptations to pregnancy that may also impact GWG [7][8][9][10][11].…”

“…Real-time, mobile tracking of REE has become increasingly popular but few devices are able to accurately estimate caloric needs [12]; further, they have rarely been used in pregnant populations [13,14]. Changes in REE during pregnancy have demonstrated an overall increase in caloric needs [8,11,[15][16][17] ranging from 13-35%. Recently, the Breezing™ device, a hand-held, Bluetooth-enabled metabolism tracker, that uses indirect calorimetry to measure REE was developed and validated against the laboratory-based Douglas Bag Method [18].…”

The effect of cisatracurium infusion on the energy expenditure of critically ill patients: an observational cohort study

“…Specific conditions expected to influence EE have been studied such as sepsis [4][5][6], burns [4,7], trauma [4,8], cerebrovascular accidents [4,9], pregnancy [10], body temperature [4], administration of sedatives [11], and therapeutic hypothermia [4,12]. An increased EE has been reported in patients with sepsis, trauma, burns, fever, and pregnancy.…”