Total energy expenditure in 9 month and 12 month infants

Body composition data show that high BMI centiles overdiagnose obesity in children aged under 6 years

BACKGROUND

Most authorities define childhood overweight/obesity as a BMI exceeding the same high centile cutoff at all ages, but it seems unlikely that true obesity prevalence (excess body fat) is constant throughout childhood.

OBJECTIVES

We investigated how fat mass (FM) and lean mass (LM), adjusted for height, relate to BMI and each other across childhood, using a uniquely large database of body composition measures, estimated using gold standard methods.

METHODS

Cross-sectional and cohort data were collated from representative samples of healthy children aged 6 wk to 20 y and children attending obesity clinics aged 7-16 y. Body composition was measured by deuterium dilution up to age 4 y, and by either deuterium or the criterion 4-component model from 4 to 20 y. FM and LM were expressed, respectively, as fat mass index (FMI; FM/height2) and lean mass index (LMI; LM/height2).

RESULTS

There were 2367 measurements of weight, height, and body composition from 1953 individuals. Before age 6 y, the variability in FMI, LMI, and BMI was much less than after; FMI was low (mainly <8 kg/m2) and FMI and LMI were weakly negatively correlated. From mid-childhood, upper limits for both BMI and FMI rose, but FMI in children with BMI <91st centile still rarely exceeded 8. With increasing age, the correlation of FMI with LMI rose to 0.5-0.7, driven mainly by children with a high FMI also having a high LMI.

CONCLUSIONS

Raised fat levels are much less common at younger than older ages, and young children with a high BMI centile have lower FMI than older children with the same BMI centile. Current BMI centile cutoffs thus overdiagnose obesity in younger groups. More stringent cutoffs are required for children aged <6 y, matching the WHO recommendation for 0-5 y.

Validation of a pre-coded food record for infants and young children

BACKGROUND/OBJECTIVES

To assess the validity of a 7-day pre-coded food record (PFR) method in 9-month-old infants against metabolizable energy intake (ME(DLW)) measured by doubly labeled water (DLW); additionally to compare PFR with a 7-day weighed food record (WFR) in 9-month-old infants and 36-month-old children.

SUBJECTS/METHODS

The study population consisted of 36 infants (age: 9.03±0.2 months) and 36 young children (age: 36.1±0.3 months) enrolled in a cross-over design of 7 consecutive days PFR vs 7 consecutive days WFR. Children were randomly assigned to one method during week 1, crossing over to the alternative method in week 2. Total energy expenditure (TEE) and ME(DLW) were obtained in the 9-month-old infants using the DLW technique for 7 days while recording with PFR.

RESULTS

For the 9-month-old group, PFR showed a mean bias of +726 kJ/day, equivalent to 24%, (P<0.0001) compared with ME(DLW) (n=29). Using WFR as the reference in this group no between-method differences were found for energy, fat and carbohydrate. Energy intake in the 36-month-old children was 12% higher in the PFR vs WFR (P<0.0001), and protein plus total fat intake were overestimated with the PFR (P=0.008, P<0.0001, respectively).

CONCLUSIONS

The study indicates that the PFR may be a valuable tool for measuring energy, energy-yielding nutrients and foods in groups of 9-month-olds infants and 36-month-olds young children.

Correcting physical activity energy expenditure for body size in children

Being able to compare the energy cost of physical activity across and between populations is important. However, energy expenditure is related to body size, so it is necessary to appropriately adjust for differences in body size when comparisons are made. This study examined the relationship between the daily energy cost of activity and body weight in 47 children aged 6-10 years. Log-log regression showed weight1.0 to be an inappropriate adjustment for activity energy expenditure in children, with a more valid adjustment being weight0.3. Clearly, both weight dependent and non-weight dependent activities are part of everyday living in children. This balance influences how energy expenditure is correctly adjusted for body size. Investigators interpreting data of energy expenditure in children from children of different body sizes need to take this into consideration.

Socio-economic and environmental factors influence energy utilization in Brazilian breast-fed infants

Energy intake recommendations for infants are based on data from industrialized countries. FAO/WHO/UNU expressed the need for studies on total energy expenditure (TEE) and basal metabolic rate from developing countries covering current and changing lifestyles. For this observational study, 65 infants of differing socioeconomic status (SES) (n = 32 middle SES, n = 33 low SES) were selected in Pelotas, southern Brazil, aiming to: 1) compare TEE, minimum observable energy expenditure (MOEE), activity energy expenditure (AEE) between breast-fed infants 8.7 mo of age from middle and low SES; and 2) investigate the effect of potential mediating factors on TEE and AEE. TEE and total body water were measured with doubly labeled water, MOEE with respiration calorimetry, breast milk intake using the dose-to-the-mother deuterium-oxide turnover method, food intake using 1-d food weighing, and prevalence of overweight using BMI Z-scores. TEE adjusted for ethnicity was 257 (95% CI 232-281) kJ/(kg . d) in middle SES infants vs. 318 (95%CI 294-342) kJ/(kg . d) in low SES infants (P = 0.001). MOEE did not differ between groups and the difference in TEE was therefore attributed to AEE (P = 0.008). The effect of SES on AEE was mediated by the number of persons per bedroom (crowding). Prevalence of overweight tended to be higher in middle SES infants (P = 0.054) than in low SES infants. The difference in TEE and AEE between SES groups emphasizes the importance of an accurate description of the SES of any population in which TEE is studied and questions the extent to which TEE data from middle-class infants in transitional countries should be considered normative.

Energy requirements of infants

OBJECTIVE

To estimate the energy requirements of infants from total energy expenditure and energy deposition during growth.

DESIGN

Energy requirements during infancy were estimated from total energy expenditure measured by the doubly labelled water method and energy deposition based on measured protein and fat gains.

SETTING

Database on the total energy expenditure and energy deposition of infants was compiled from available studies conducted in China, Chile, Gambia, Mexico, The Netherlands, UK, and USA.

SUBJECTS

Healthy, term infants.

RESULTS

Total energy requirements (kJ day(-1)) increased with age and were higher in boys than girls due to differences in weight. Energy requirements decreased from 473 kJ kg(-1) per day for boys and 447 kJ kg(-1) per day for girls at 1 month of age to 337 kJ kg(-1) per day for boys and 341 kJ kg(-1) per day for girls at 6 months of age, and thereafter tended to plateau. Energy deposition as a percentage of total energy requirements decreased from 40% at 1 month to 3% at 12 months of age. These estimates are 10-32% lower than the 1985 FAO/WHO/UNU recommendations which were based on observed energy intakes of infants.

CONCLUSIONS

Recommendations for the energy intake of infants should be revised based on new estimates of total energy expenditure and energy deposition.

The pragmatics of feeding the pediatric patient with acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) represents the ultimate pulmonary response to a wide range of injuries, from septicemia to trauma. Optimal nutrition is vital to enhancing oxygen delivery, supporting adequate cardiac contractility and respiratory musculature, eliminating fluid and electrolyte imbalances, and supporting the proinflammatory response. Research is providing a better understanding of nutrients that specifically address the complex physiologic changes in ARDS. This article highlights the pathophysiology of ARDS as it relates to nutrition, relevant nutritional assessment, and important enteral and parenteral considerations for the pediatric patient who has ARDS.

Habitual physical activity and physical activity intensity: their relation to body composition in 5.0–10.5-y-old children

BACKGROUND

Concerns of a decrease in physical activity levels (PALs) of children and a concurrent increase in childhood obesity exist worldwide. The exact relation between these two parameters however has as yet to be fully defined in children.

OBJECTIVE

This study examined the relation in 47 children, aged 5-10.5 y (mean age 8.4+/-0.9 y) between habitual physical activity, minutes spent in moderate, vigorous and hard intensity activity and body composition parameters.

DESIGN

Total energy expenditure (TEE) was calculated using the doubly labelled water technique and basal metabolic rate (BMR) was predicted from Schofield's equations. PAL was determined by PAL=TEE/BMR. Time spent in moderate, vigorous and hard intensity activity was determined by accelerometry, using the Tritrac-R3D. Body fatness and body mass index (BMI) were used as the two measures of body composition.

RESULTS

Body fat and BMI were significantly inversely correlated with PAL (r=-0.43, P=0.002 and r=-0.45, P=0.001). Times spent in vigorous activity and hard activity were significantly correlated to percentage body fat (r=-0.44, P=0.004 and r=-0.39, P=0.014), but not BMI. Children who were in the top tertiles for both vigorous activity and hard activity had significantly lower body fat percentages than those in the middle and lowest tertiles. Moderate intensity activity was not correlated with measures of body composition.

CONCLUSIONS

As well as showing a significant relation between PAL and body composition, these data intimate that there may be a threshold of intensity of physical activity that is influential on body fatness. In light of world trends showing increasing childhood obesity, this study supports the need to further investigate the importance of physical activity for children.

Total energy expenditure and physical activity level in healthy young Swedish children 9 or 14 months of age

OBJECTIVES

To measure total energy expenditure (TEE) and total body water (TBW) in healthy Swedish children 9 or 14 months of age. To compare their TEE with current recommendations for energy intake. To define their body composition and relate this to energy expenditure.

DESIGN

: Children were investigated at 9 or 14 months. The following variables were measured: TEE and TBW (by the doubly labelled water method), weight and length. Total body fat (TBF), sleeping metabolic rate, activity energy expenditure and physical activity level (PAL) were calculated.

SUBJECTS

Thirty infants 9 months of age and 29 children 14 months of age.

RESULTS

: TEE was 323+/-38, 322+/-29, 313+/-23 and 331+/-28 kJ/kg/day in 9-month-old girls, 9-month-old boys, 14-month-old girls and 14-month-old boys, respectively. At 9 months of age girls and boys contained 29.6+/-4.8 and 29.7+/-4.5% TBF, respectively. At 14 months the corresponding figures were 29.1+/-4.3 and 28.2+/-4.3%. There was a significant negative relationship between PAL and %TBF (r=-0.81, P<0.001, n=59).

CONCLUSIONS

Measured TEE plus calculated energy cost of growth confirm previous estimates that the physiological energy requirements of children 9 and 14 months of age are 15-20% lower than current recommendations for energy intake. One possible interpretation of the relationship between PAL and %TBF is that children with a high TBF content are less physically active than children with less TBF. However, this relationship needs further studies.

Longitudinal investigation of energy expenditure in infants with cystic fibrosis

OBJECTIVE

To determine when energy expenditure becomes elevated in infants with cystic fibrosis (CF).

DESIGN

Longitudinal studies of total energy expenditure (TEE) using doubly labeled water were conducted in infants identified with CF by newborn screening through the first year of life.

SETTING

Hospital and community based studies in Denver, Colorado, USA and Cambridge, UK.

RESULTS

Eight of the 12 infants enrolled had begun enzyme therapy but were clinically asymptomatic. Four of the 12 infants were heterozygous for the delta F508 mutation, however no difference was seen in TEE from the remaining homozygous infants. TEE was compared to control cohorts at 2, 6 and 12 months of age. There was no difference from the control groups in TEE/kg fat free mass (FFM)/day at 2 months. However, by 6 months of age TEE/kg FFM/day in infants with CF exceeded that of age-matched controls by 25% (P<0.001). This elevation in TEE continued at 12 months of age exceeding that of controls by 30% (P<0.05).

CONCLUSIONS

These results indicate that infants with CF have increased energy needs by 6 months of age and that early diagnosis alone does not prevent the development of increased caloric requirements. These findings emphasize the need for close nutritional monitoring to prevent suboptimal growth during infancy in this population.

SPONSORSHIP

This research was supported by grant number 5 MO1 RR00069, General Clinical Research Centers Program, National Center for Research Resources, NIH.

Physical activity at 9-12 months and fatness at 2 years of age

Previous research has shown that physical activity in early infancy does not predict later fatness, whereas in preschool children, such a relationship is found. The objective of this study was to investigate whether total energy expenditure (TEE) and behavior in late infancy are related to subcutaneous and total fatness in early childhood. Twenty-six infants were studied at 9-12 months and followed up at 2 years of age. Anthropometry, body composition, TEE, and behavior were measured in late infancy; skinfold thicknesses and total body fat were measured at 2 years of age. Infant TEE adjusted for fat-free mass was not related to later fatness. Infant behavior was related to later subcutaneous fatness, but not to total body fatness. Lower levels of infant activity were associated with greater skinfold thicknesses in childhood. Thus, by late infancy, physical activity level is related to subsequent skinfold thickness. Particular aspects of infant behavior appear to be more important than the sum of energy expended on activity. However, the relationship did not extend to total body fat.

Energy requirements derived from total energy expenditure and energy deposition during the first 2 y of life

BACKGROUND

Current recommendations for energy intake of children are derived from observed intakes. Deriving energy requirements on the basis of energy expenditure and deposition is scientifically more rational than is using the observational approach and is now possible with data on total energy expenditure (TEE), growth, and body composition.

OBJECTIVES

The objectives of this study were 1) to define energy requirements during the first 2 y of life on the basis of TEE and energy deposition; 2) to test effects of sex, age, and feeding mode on energy requirements; and 3) to determine physical activity.

DESIGN

TEE, sleeping metabolic rate, anthropometry, and body composition were measured in 76 infants. TEE was measured with doubly labeled water, sleeping metabolic rate with respiratory calorimetry, and body composition with a multicomponent model.

RESULTS

Total energy requirements were 2.23, 2.59, 2.97, 3. 38, 3.72, and 4.15 MJ/d at 3, 6, 9, 12, 18, and 24 mo, respectively. Energy deposition (in MJ/d) decreased significantly over time (P: = 0.001) and was lower in breast-fed than in formula-fed infants (P: = 0.01). Energy requirements were approximately 80% of current recommendations. Energy requirements differed by age (P: = 0.001), feeding group (P: = 0.03), and sex (P: = 0.03). Adjusted for weight or fat-free mass and fat mass, energy requirements still differed by feeding group but not by age or sex. Temperament and motor development did not affect TEE.

CONCLUSION

The TEE and energy-deposition data of these healthy, thriving children provide strong evidence that current recommendations for energy intake in the first 2 y of life should be revised.

Estimation of the energy cost of physical activity in infancy

OBJECTIVE

To estimate physical activity energy expenditure (AEE) in groups of free living infants in the first year of life.

DESIGN

Mixed longitudinal study of 124 healthy infants, using 232 estimations of AEE made between 1.5 and 12 months. Infants studied at more than one time point were treated as new cross sectional data points. Total energy expenditure and body composition were estimated using doubly labelled water. Sleeping metabolic rate was predicted from weight.

RESULTS

AEE increased from 5% of energy intake at 1.5 months to 34% at 12 months. Growth costs declined by 90%, but metabolisable intake by only 20%, over the same period.

CONCLUSIONS

Energy is increasingly diverted from growth to activity during infancy. Values for AEE may aid in estimating energy requirements of groups factorially. Further work is required, however, on individual variability in AEE, and on the effects of disease, hospitalisation, surgery, and malnutrition.