Energy balance during recovery from malnutrition

Greater energy surplus promotes body protein accretion in healthy young men: A randomized clinical trial

BACKGROUND & AIMS

Caloric overfeeding combined with adequate protein intake increases not only body fat mass but also fat-free mass. However, it remains unclear whether the increase in fat-free mass due to overfeeding is associated with an increase in total body protein mass. We evaluated the hypothesis that overfeeding would promote an increase in total body protein mass.

METHODS

In our randomized controlled trial, 23 healthy young men were fed a diet equivalent to their energy requirements with a +10 % energy surplus from protein alone or a +40 % energy surplus (+10 % from protein, +30 % from carbohydrate) for 6 weeks. We estimated total body protein mass by a four-compartment model using dual-energy X-ray absorptiometry, deuterium dilution, and hydrostatic underwater weighing.

RESULTS

The 40 % energy surplus over 6 weeks significantly increased body protein mass compared to baseline by 3.7 % (0.44 kg; 95 % confidence interval [CI], 0.21-0.67 kg; P = 0.003); however, the 10 % energy surplus did not result in a significant change (0.00 kg; 95 % CI, -0.38-0.39 kg; P = 0.980). A significant interaction between intervention duration (time) and energy surplus (group) was observed for total body protein mass (P = 0.035, linear mixed-effects model), with a trend toward a significant difference in total body protein mass gain between groups (P = 0.059, Wilcoxon rank sum test). The increase in body protein mass due to the energy surplus was correlated with an increase in fat mass (r = 0.820, p = 0.002).

CONCLUSIONS

A higher energy intake was found to promote an increase in body protein mass in healthy men consuming excess protein, suggesting the importance of energy surplus in body protein accumulation. This effect of energy surplus may be related to factors such as increased body fat mass and the associated secretion of adipokines.

TRIAL REGISTRATION

The trial was registered with the University Hospital Medical Information Network Clinical Trial Registry as UMIN000034158.

Energy expenditure, intake and availability in female soccer players via doubly labelled water: Are we misrepresenting low energy availability?

Female soccer players have been identified as presenting with low energy availability (LEA), though the prevalence of LEA may be overestimated given inaccuracies associated with self-reporting dietary intakes. Accordingly, we aimed to quantify total daily energy expenditure (TDEE) via the doubly labelled water (DLW) method, energy intake (EI) and energy availability (EA). Adolescent female soccer players (n = 45; 16 ± 1 years) completed a 9-10 day 'training camp' representing their national team. Absolute and relative TDEE was 2683 ± 324 and 60 ± 7 kcal kg-1 fat free mass (FFM), respectively. Mean daily EI was lower (P < 0.01) when players self-reported using the remote food photography method (RFPM) (2047 ± 383 kcal day-1) over a 3-day period versus DLW derived EI estimates accounting for body mass (BM) changes (2545 ± 518 kcal day-1) over 7-8 days, representing a mean daily Δ of 499 ± 526 kcal day-1 and 22% error when using the RFPM. Estimated EA was different (P < 0.01) between methods (DLW: 48 ± 14 kcal kg-1 FFM, range: 22-82; RFPM: 37 ± 8 kcal kg-1 FFM, range: 22-54), such that prevalence of LEA (<30 kcal kg-1 FFM) was lower in DLW compared with RFPM (5% vs. 15%, respectively). Data demonstrate the potential to significantly underestimate EI when using self-report methods. This approach can therefore cause a misrepresentation and an over-prevalence of LEA, which is the underlying aetiology of 'relative energy deficiency in sport' (REDs). HIGHLIGHTS: What is the central question of this study? Do self-reported dietary intakes (via remote food photography method, RFPM) overestimate low energy availability (LEA) prevalence in female soccer players compared with energy intake evaluation from the doubly labelled water (DLW) method? What is the main finding and its importance? Estimated energy availability is greater with the DLW method compared with RFPM, such that the prevalence of LEA is greater when self-reporting dietary intakes. Accordingly, data demonstrate the potential to misrepresent the prevalence of LEA, an underlying factor in the aetiology of 'relative energy deficiency in sport' (REDs).

A Randomized Trial of Healthy Weight Gain in Athletic Individuals

PURPOSE

The purpose of this study is to evaluate the outcomes of a 10-wk diet and exercise regimen designed to promote healthy weight gain with excess energy from peanut-containing or high-carbohydrate foods.

METHODS

Nineteen male and 13 female athletes were randomly assigned to receive an additional 500 kcal·d -1 above typical intake through provision of either peanut-based whole foods/snacks (PNT group) or a similar, high-carbohydrate, peanut-free snack (CHO group) along with supervised, whole-body RT (3 d·wk -1 for 60-120 min). Body composition was assessed by dual-energyx-ray absorptiometry at baseline and postintervention.

RESULTS

Total body mass (TBM) increased 2.2 ± 1.3 kg with 1.5 ± 1.1 kg as LBM after week 10. The PNT group ( n = 16; 27 ± 7 yr; 10 men, 6 women) gained less TBM than the CHO group ( n = 16; 23 ± 3 yr; 9 men, 7 women) (1.6 ± 1.1 kg vs 2.7 ± 1.2 kg, respectively, P = 0.007) with no differences in LBM (1.2 ± 1.1 kg vs 1.9 ± 1.0 kg, P = 0.136).

CONCLUSIONS

These results suggest that the addition of 500 kcal·d -1 from whole foods/snacks in combination with a rigorous RT program promotes a similar weight gain of ~0.22 kg·wk -1 , primarily as LBM, over 10 wk in both male and female athletes. However, snack macronutrient content may impact the effectiveness of this regimen.

The recent WHO guideline on acute malnutrition overestimates therapeutic energy requirement

The World Health Organization has recently updated the guideline on the prevention and management of wasting and nutritional oedema (acute malnutrition) in infants and children under 5 years. Apart from differences with regard to the nutritional framework that defines the quantity of energy required as Ready-to-Use Therapeutic Food (RUTF) for the outpatient treatment of severe wasting and/or nutritional oedema, there are also important gaps in the practical guidance. Instead of the recommended energy intake of 150-185 kcal/kg/day, our alternative calculations indicate the requirement to be only 105-120 kcal/kg/day. If true, the implementation of such caloric overfeeding can have adverse consequences. Gaps in practical guidance also need to be addressed, including the timing of transition to home-based diets, maximal duration of therapeutic feeding, especially in non-responders (∼50% in South Asia), and the role of augmented home foods as the primary therapeutic food option.

Trajectories of resting energy expenditure and performance of predictive equations in children hospitalized with an acute illness and malnutrition: a longitudinal study

There is scarce data on energy expenditure in ill children with different degrees of malnutrition. This study aimed to determine resting energy expenditure (REE) trajectories in hospitalized malnourished children during and after hospitalization. We followed a cohort of children in Bangladesh and Malawi (2-23 months) with: no wasting (NW); moderate wasting (MW), severe wasting (SW), or edematous malnutrition (EM). REE was measured by indirect calorimetry at admission, discharge, 14-and-45-days post-discharge. 125 children (NW, n = 23; MW, n = 29; SW, n = 51; EM, n = 22), median age 9 (IQR 6, 14) months, provided 401 REE measurements. At admission, the REE of children with NW and MW was 67 (95% CI [58, 75]) and 70 (95% CI [63, 76]) kcal/kg/day, respectively, while REE in children with SW was higher, 79 kcal/kg/day (95% CI [74, 84], p = 0.018), than NW. REE in these groups was stable over time. In children with EM, REE increased from admission to discharge (65 kcal/kg/day, 95% CI [56, 73]) to 79 (95% CI [72, 86], p = 0.0014) and was stable hereafter. Predictive equations underestimated REE in 92% of participants at all time points. Recommended feeding targets during the acute phase of illness in severely malnourished children exceeded REE. Acutely ill malnourished children are at risk of being overfed when implementing current international guidelines.

Metabolic adaptation after combined resistance and aerobic exercise training in older women

OBJECTIVE

This study investigated whether combined aerobic and resistance training in older women leads to metabolic adaptation.

METHODS

A total of 80 women (64 White individuals; BMI: 30.0 [4.4] kg/m² ; age: 64.8 [3.5] years) followed 32 weeks of aerobic and resistance training. Body weight/composition (dual-energy X-ray absorptiometry) and resting metabolic rate (RMR; indirect calorimetry) were measured at baseline, week 16, and week 32. Metabolic adaptation was defined as significantly lower measured versus predicted RMR. A regression model to predict metabolic adaptation was developed that included race, age, baseline fat-free mass, RMR and respiratory quotient, and changes in net submaximal oxygen consumption after different tasks.

RESULTS

There was significant metabolic adaptation at week 16 (-59 [136] kcal/d, p = 0.002), following a 640-kcal/wk energy loss (-0.7 [2.6] kg of weight loss). In 53 women with complete data, metabolic adaptation was seen both at week 16 (-64 [129] kcal/d, p = 0.001) and at week 32 (-94 [127] kcal/d, p < 0.001). Metabolic adaptation at week 16 was predicted by race, age, baseline fat-free mass, RMR and respiratory quotient, and change in net oxygen consumption of walking (R² adjusted = 0.90, p < 0.001). Similar results were seen at week 32.

CONCLUSIONS

In older women with overweight and obesity, a minimal energy deficit induced by aerobic and resistance exercise is associated with metabolic adaptation at the level of RMR.

Metabolic adaptation delays time to reach weight loss goals

OBJECTIVE

The aim of this study was to determine whether metabolic adaptation, at the level of resting metabolic rate, was associated with time to reach weight loss goals, after adjusting for confounders.

METHODS

A total of 65 premenopausal women with overweight (BMI: 28.6 ± 1.5 kg/m2 ; age: 36.4 ± 5.9 years; 36 were White, and 29 were Black) followed an 800-kcal/d diet until BMI ≤25 kg/m2 . Body weight and composition were measured at baseline and after weight loss. Dietary adherence was calculated from total energy expenditure, determined by double labeled water, and body composition changes. Metabolic adaptation was defined as a significantly lower measured versus predicted resting metabolic rate (from own regression model). A regression model to predict time to reach weight loss goals was developed including target weight loss, energy deficit, dietary adherence, and metabolic adaptation as predictors.

RESULTS

Participants lost on average 12.5 ± 3.1 kg (16.1% ± 3.4%) over 155.1 ± 49.2 days. Average dietary adherence was 63.6% ± 31.0%. There was significant metabolic adaptation after weight loss (-46 ± 113 kcal/d, p = 0.002) and this variable was a significant predictor of time to reach weight loss goals (β = -0.1, p = 0.041), even after adjusting for confounders (R2 adjusted = 0.63, p < 0.001).

CONCLUSION

In premenopausal women with overweight, metabolic adaptation after a 16% weight loss increases the length of time necessary to achieve weight loss goals.

Weight and mid-upper arm circumference gain velocities during treatment of young children with severe acute malnutrition, a prospective study in Uganda

Background

Weight gain is routinely monitored to assess hydration and growth during treatment of children with complicated severe acute malnutrition (SAM). However, changes in weight and mid-upper arm circumference (MUAC) gain velocities over time are scarcely described. We assessed weight and MUAC gain velocities in 6–59 mo-old children with complicated SAM by treatment phase and edema status.

Methods

This was a prospective study, nested in a randomized/probiotic trial (ISRCTN16454889). Weight and MUAC gain velocities were assessed by treatment phase and edema at admission using linear mixed-effects models.

Results

Among 400 children enrolled, the median (IQR) age was 15.0 (11.2;19.2) months, 58% were males, and 65% presented with edema. During inpatient therapeutic care (ITC), children with edema vs no edema at admission had negative weight gain velocity in the stabilization phase [differences at day 3 and 4 were − 11.26 (95% CI: − 20.73; − 1.79) g/kg/d and − 13.09 (95% CI: − 23.15; − 3.02) g/kg/d, respectively]. This gradually changed into positive weight gain velocity in transition and eventually peaked at 12 g/kg/d early in the rehabilitation phase, with no difference by edema status (P > 0.9). During outpatient therapeutic care (OTC), overall, weight gain velocity showed a decreasing trend over time (from 5 to 2 g/kg/d), [difference between edema and non-edema groups at week 2 was 2.1 (95% CI: 1.0;3.2) g/kg/d]. MUAC gain velocity results mirrored those of weight gain velocity [differences were − 2.30 (95% CI: − 3.6; − 0.97) mm/week at week 1 in ITC and 0.65 (95% CI: − 0.07;1.37) mm/week at week 2 in OTC].

Conclusions

Weight and MUAC gain velocities among Ugandan children with complicated SAM showed an increasing trend during transition and early in the rehabilitation phase, and a decreasing trend thereafter, but, overall, catch-up growth was prolonged. Further research to establish specific cut-offs to assess weight and MUAC gain velocities during different periods of rehabilitation is needed.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40795-021-00428-0.

Metabolic adaptation is associated with less weight and fat mass loss in response to low-energy diets

BACKGROUND

The practical relevance of metabolic adaptation remains a controversial issue. To the best of our knowledge, no study has properly evaluated the role of metabolic adaptation in modulating weight loss outcomes. Therefore, the aim of this study was to determine the association between metabolic adaptation, at the level of resting metabolic rate (RMR), and weight and fat mass (FM) loss after low-energy diets (LED), after adjusting for dietary adherence and other confounders.

METHODS

71 individuals with obesity (BMI: 34.6 ± 3.4 kg/m2; age: 45.4 ± 8.2 years; 33 males) were randomized to one of three 1000 kcal/day diets for 8 weeks. Body weight, FM and fat-free mass (FFM) (air displacement plethysmography), RMR (indirect calorimetry) and physical activity level (PAL) (armbands) were measured at baseline and at week 9. Metabolic adaptation at week 9 was defined as measured RMR minus predicted RMR at week 9. An equation to predict RMR was derived from baseline data of all participants that were part of this analysis and included age, sex, FM and FFM as predictors. Dietary adherence was calculated from RMR, PAL and body composition changes. Linear regression was used to assess the potential role of metabolic adaptation in predicting weight and FM loss after adjusting for dietary adherence, average PAL, sex, baseline FM and FFM and randomization group.

RESULTS

Participants lost on average 14 ± 4 kg of body weight (13 ± 3%) and presented with metabolic adaptation (-92 ± 110 kcal/day, P < 0.001). Metabolic adaptation was a significant predictor of both weight (β = -0.009, P < 0.001) and FM loss (β = -0.008, P < 0.001), even after adjusting for confounders (R2 = 0.88, 0.93, respectively, P < 0.001 for both). On average, an increase in metabolic adaptation of 50 kcal/day was associated with a 0.5 kg lower weight and FM loss in response to the LED.

CONCLUSION

In individuals with obesity, metabolic adaptation at the level of RMR is associated with less weight and FM loss in response to LED. Trial registration ID: NCT02944253.

Acute malnutrition recovery energy requirements based on mid-upper arm circumference: Secondary analysis of feeding program data from 5 countries, Combined Protocol for Acute Malnutrition Study (ComPAS) Stage 1

Background

Severe and moderate acute malnutrition (SAM and MAM) are currently treated with different food products in separate treatment programs. The development of a unified and simplified treatment protocol using a single food product aims to increase treatment program efficiency and effectiveness. This study, the first stage of the ComPAS trial, sought to assess rate of growth and energy requirements among children recovering from acute malnutrition in order to design a simplified, MUAC-based dosage protocol.

Methods

We obtained secondary data from patient cards of children aged 6–59 months recovering from SAM in outpatient therapeutic feeding programs (TFPs) and from MAM in supplementary feeding programs (SFPs) in five countries in Africa and Asia. We used local polynomial smoothing to assess changes in MUAC and proportional weight gain between clinic visits and assessed their normalized differences for a non-zero linear trend. We estimated energy needs to meet or exceed the growth observed in 95% of visits.

Results

This analysis used data from 5518 patients representing 33942 visits. Growth trends in MUAC and proportional weight gain were not significantly different, each lower at higher MUAC values: MUAC growth averaged 2mm/week at lower MUACs (100 to <110mm) and 1mm/week at higher MUACs (120mm to <125mm); and proportional weight gain declined from 3.9g/kg/day to 2.4g/kg/day across the same MUAC values. In 95% of visits by children with a MUAC 100mm to <125mm who were successfully treated, energy needs could be met or exceeded with 1,000 kilocalories a day.

Conclusion

Two 92g sachets of Ready-to-Use Therapeutic Food (RUTF) (1,000kcal total) is proposed to meet the estimated total energy requirements of children with a MUAC 100mm to <115mm, and one 92g sachet of RUTF (500kcal) is proposed to meet half the energy requirements of children with a MUAC of 115 to <125mm. A simplified, combined protocol may enable a more holistic continuum of care, potentially contributing to increased coverage for children suffering from acute malnutrition.

Energy needs in the treatment of uncomplicated severe acute malnutrition: Secondary analysis to optimize delivery of ready-to-use therapeutic foods

Outpatient therapeutic feeding protocols for the treatment of uncomplicated severe acute malnutrition in children were initially based on weight gain data from inpatient settings and expert knowledge of the physiological requirements during recovery. However, weight gain and energy requirements from historic inpatient settings may differ from modern outpatient settings and therefore may not be appropriate to guide current therapeutic feeding protocols. We calculated the weight gain and average estimated total daily energy requirement of children successfully treated for uncomplicated severe acute malnutrition as outpatients in Niger (n = 790). Mean energy provided by six therapeutic feeding protocols was calculated and compared with average estimated energy requirements in the study population. Overall weight gain was 5.5 g·kg^-1 ·day^-1 among recovered children. Average energy requirements ranged from 92 to 110 kcal·kg^-1 ·day^-1 depending on the estimation approach. Two current therapeutic feeding protocols were found to provide an excess of energy after the first week of treatment in our study population, whereas four research protocols tended to provide less energy than the estimated requirement after the first week of treatment. Alternative feeding protocols have the potential to simplify and lead to important savings for programmes but should be evaluated to show adequacy to meet the energy needs of children under treatment, as well as feasibility and cost efficiency. Our findings rely on theoretical calculations based on several assumptions and should be confirmed in field studies.

Is an Energy Surplus Required to Maximize Skeletal Muscle Hypertrophy Associated With Resistance Training

Resistance training is commonly prescribed to enhance strength/power qualities and is achieved via improved neuromuscular recruitment, fiber type transition, and/ or skeletal muscle hypertrophy. The rate and amount of muscle hypertrophy associated with resistance training is influenced by a wide array of variables including the training program, plus training experience, gender, genetic predisposition, and nutritional status of the individual. Various dietary interventions have been proposed to influence muscle hypertrophy, including manipulation of protein intake, specific supplement prescription, and creation of an energy surplus. While recent research has provided significant insight into optimization of dietary protein intake and application of evidence based supplements, the specific energy surplus required to facilitate muscle hypertrophy is unknown. However, there is clear evidence of an anabolic stimulus possible from an energy surplus, even independent of resistance training. Common textbook recommendations are often based solely on the assumed energy stored within the tissue being assimilated. Unfortunately, such guidance likely fails to account for other energetically expensive processes associated with muscle hypertrophy, the acute metabolic adjustments that occur in response to an energy surplus, or individual nuances like training experience and energy status of the individual. Given the ambiguous nature of these calculations, it is not surprising to see broad ranging guidance on energy needs. These estimates have never been validated in a resistance training population to confirm the "sweet spot" for an energy surplus that facilitates optimal rates of muscle gain relative to fat mass. This review not only addresses the influence of an energy surplus on resistance training outcomes, but also explores other pertinent issues, including "how much should energy intake be increased," "where should this extra energy come from," and "when should this extra energy be consumed." Several gaps in the literature are identified, with the hope this will stimulate further research interest in this area. Having a broader appreciation of these issues will assist practitioners in the establishment of dietary strategies that facilitate resistance training adaptations while also addressing other important nutrition related issues such as optimization of fuelling and recovery goals. Practical issues like the management of satiety when attempting to increase energy intake are also addressed.

Sarcopenia and Its Implications for Metabolic Health

Sarcopenia not only affects the ability to lead an active lifestyle but also contributes to increased obesity, reduced quality of life, osteoporosis, and metabolic health, in part due to reduced locomotion economy and ease. On the other hand, increased obesity, decreased quality of life, and reduced metabolic health also contribute to sarcopenia. The purpose of this mini-review is to discuss the implications sarcopenia has for the development of obesity and comorbidities that occur with aging.

Changes in Plasma Somatomedin-C in Response to Ingestion of Diets with Variable Protein and Energy Content

We have attempted to determine the relative importance of dietary intake of protein and energy in restoring plasma immunoreactive somatomedin-C (Sm-C) concentrations after fasting. Ten healthy human volunteers were fasted for 5 days, then divided into two refeeding groups. One group (variable energy) was refed 1.0 g protein/kg ideal body weight, and in 9-day sequences, 11, 18 and 25 kcal of energy/kg. The other group (variable protein) was given 35 kcal energy/kg, and in 9-day sequences, 0.2, 0.4, and 1.0 g protein/kg. When subjects were refed the variable energy diets there was no significant increase in Sm-C at 11 kcal/kg (0.47 +/- 0.13 to 0.45 +/- 0.12 U/ml), suggesting that there is a threshold energy requirement below which optimal protein intake is not sufficient to raise the Sm-C. When subjects were refed 18 and 25 kcal/kg, it became apparent that the more energy added to the diet, the greater the absolute concentration of Sm-C attained (0.66 U/ml on 18 kcal/kg and 0.97 U/ml on 25 kcal/kg). Sm-C correlated with nitrogen balance (r = 0.58) during refeeding with the variable energy diets and was a good indicator of acute directional change in nitrogen balance. However, Sm-C was not a reliable indicator of nitrogen repletion, since it rose almost to control levels on the 25 kcal/kg diet while nitrogen balance remained slightly negative.(ABSTRACT TRUNCATED AT 250 WORDS)

Cereals and pulse-based ready-to-use therapeutic food as an alternative to the standard milk- and peanut paste-based formulation for treating severe acute malnutrition: a noninferiority, individually randomized controlled efficacy clinical trial

BACKGROUND

The cost of current standard ready-to-use therapeutic food (RUTF) is among the major obstacles to scaling up community-based management of acute malnutrition (CMAM), an important child survival strategy. Identifying a cheaper alternative is a global public health priority.

OBJECTIVE

We sought to compare the efficacy of soya-maize-sorghum RUTF (SMS-RUTF) with that of standard peanut paste-based RUTF (P-RUTF).

DESIGN

We used a nonblinded, parallel-group, simple randomized controlled trial along with a day care approach that enrolled 2 groups of children aged 6-23 and 24-59 mo, respectively, with severe acute malnutrition (SAM).

RESULTS

Intention-to-treat (ITT) and per-protocol (PP) analyses showed noninferiority of SMS-RUTF compared with P-RUTF for the recovery rate [ITT: Δ = -2.0% (95% CI: -7.6%, 3.6%); PP: -1.9% (95% CI: -5.3%, 1.4%)], weight gain [Δ = -0.7 g · kg(-1)· d(-1)(95% CI: -1.3, 0.0 g · kg(-1)· d(-1))], and length of stay [Δ = 2.0 d (95% CI: -1.7, 5.8 d)] in children ≥24 mo of age. In children ≤23 mo of age, the recovery rate of SMS-RUTF was inferior to that of P-RUTF [ITT: Δ = -20.8% (95% CI: -29.9%, -11.7%); PP: -17.2% (95% CI: -25.6%, -8.7%)]. Treatment with SMS-RUTF resulted in a greater increase in hemoglobin [0.670 g/dL (95% CI: 0.420, 0.921 g/dL);P< 0.001]. Treatment with both RUTFs resulted in the replenishment of all of the amino acids tested except for methionine. There were no differences at discharge between RUTF groups in fat mass [Δ = 0.3 kg (95% CI: -0.6, 1.6 kg);P= 0.341] or fat mass index [Δ = 0.4 kg/m(2)(95% CI: -0.3, 1.1 kg/m(2));P= 0.262]. By contrast, comparisons of fat-free mass indicated lower concentrations than the community controls after treatment with either of the 2 RUTFs [Δ = -1.3 kg (95% CI: -2.4, -0.1 kg) andP= 0.034 for comparison between community controls and the SMS-RUTF group; Δ = -1.8 kg (95% CI: -2.9, -0.6 kg) andP= 0.003 for comparison between community controls and the P-RUTF group].

CONCLUSION

SMS-RUTF can be used to treat SAM in children aged ≥24 mo to reduce the costs of CMAM programs. More research is required to optimize SMS-RUTF for younger children. This trial was registered in the Pan African Clinical Trial Registry as PACTR201303000475166.

Growth failure and nutrition considerations in chronic childhood wasting diseases

Growth failure is a common problem in many children with chronic diseases. This article is an overview of the most common causes of growth failure/growth retardation that affect children with a number of chronic diseases. We also briefly review the nutrition considerations and treatment goals. Growth failure is multifactorial in children with chronic conditions, including patients with cystic fibrosis, chronic kidney disease, chronic liver disease, congenital heart disease, human immunodeficiency virus, inflammatory bowel disease, short bowel syndrome, and muscular dystrophies. Important contributory factors to growth failure include increased energy needs, increased energy loss, malabsorption, decreased energy intake, anorexia, pain, vomiting, intestinal obstruction, and inflammatory cytokines. Various metabolic and pathologic abnormalities that are characteristic of chronic diseases further lead to significant malnutrition and growth failure. In addition to treating disease-specific abnormalities, treatment should address the energy and protein deficits, including vitamin and mineral supplements to correct deficiencies, correct metabolic and endocrinologic abnormalities, and include long-term monitoring of weight and growth. Individualized, age-appropriate nutrition intervention will minimize the malnutrition and growth failure seen in children with chronic diseases.

Integrating muscle cell biochemistry and whole-body physiology in humans:(31)P-MRS data from the InSight trial

We acquired ³¹P-MRS data from skeletal muscle of subjects of mixed gender and ethnicity, combined with a panel of physiological characteristics, and tested several long-standing hypotheses regarding relationships between muscle cell biochemistry and whole-body physiology with unusually high statistical power. We hypothesized that i) whole-body VO₂max would correlate with muscle respiratory capacity, ii) resting muscle phosphocreatine concentration ([PCr]) would negatively correlate with delta efficiency and iii) muscle mitochondrial function would positively correlate with both resting VO₂ and total daily energy expenditure (TDEE). Muscle respiratory capacity explained a quarter of the variation in VO₂max (r² = 26, p < .001, n = 87). There was an inverse correlation between muscle [PCr] and delta efficiency (r = −23, p = 046, n = 87). There was also a correlation between [PCr] recovery halftime and TDEE (r = −23, p = 035, n = 87). Our data not only provide insights into muscle cell chemistry and whole-body physiology but our mixed cohort means that our findings are broadly generalizable.

Validity of the Remote Food Photography Method (RFPM) for estimating energy and nutrient intake in near real-time

Two studies are reported; a pilot study to demonstrate feasibility followed by a larger validity study. Study 1's objective was to test the effect of two ecological momentary assessment (EMA) approaches that varied in intensity on the validity/accuracy of estimating energy intake (EI) with the Remote Food Photography Method (RFPM) over 6 days in free-living conditions. When using the RFPM, Smartphones are used to capture images of food selection and plate waste and to send the images to a server for food intake estimation. Consistent with EMA, prompts are sent to the Smartphones reminding participants to capture food images. During Study 1, EI estimated with the RFPM and the gold standard, doubly labeled water (DLW), were compared. Participants were assigned to receive Standard EMA Prompts (n = 24) or Customized Prompts (n = 16) (the latter received more reminders delivered at personalized meal times). The RFPM differed significantly from DLW at estimating EI when Standard (mean ± s.d. = -895 ± 770 kcal/day, P < 0.0001), but not Customized Prompts (-270 ± 748 kcal/day, P = 0.22) were used. Error (EI from the RFPM minus that from DLW) was significantly smaller with Customized vs. Standard Prompts. The objectives of Study 2 included testing the RFPM's ability to accurately estimate EI in free-living adults (N = 50) over 6 days, and energy and nutrient intake in laboratory-based meals. The RFPM did not differ significantly from DLW at estimating free-living EI (-152 ± 694 kcal/day, P = 0.16). During laboratory-based meals, estimating energy and macronutrient intake with the RFPM did not differ significantly compared to directly weighed intake.

Dietary adherence during weight loss predicts weight regain

This study examined the relationship between previous dietary adherence during a low-calorie diet weight loss intervention and subsequent weight change during a 2-year follow-up for weight maintenance. One hundred and sixteen healthy, recently weight reduced (lost ~12 kg, BMI 22-25 kg/m2) premenopausal women were studied. Dietary adherence was assessed by doubly labeled water (DLW) and body composition change. Comparisons were made between the upper and lower tertiles for previous dietary adherence and subsequent weight change at 1- and 2-year follow-up. Percent weight regained was significantly lower (30.9 ± 6.7% vs. 66.7 ± 9.4%; P < 0.05) in the upper compared to the lower adherence tertile for previous weight loss dietary adherence (49.9 ± 8.8% vs. 96.8 ± 12.8% P < 0.05) at 1- and 2-year follow-up, respectively. This difference was partly explained by increases in daily activity-related energy expenditure (AEE) (+95 ± 45 kcal/day vs. -44 ± 42 kcal/day, P < 0.05) and lower daily energy intake (2,066 ± 71 kcal/day vs. 2,289 ± 62 kcal/day, P < 0.05) in the higher tertile for previous dietary adherence, compared to the lower. These findings suggest that higher adherence (i.e., higher tertile) to the previous low-calorie diet predicts lower weight regain over 2-year follow-up for weight maintenance, which is explained by lower energy intake and higher physical activity. Finally, how well an individual adheres to a low-calorie diet intervention during weight loss may be a useful tool for identifying individuals who are particularly vulnerable to subsequent weight regain.

A cellular level approach to predicting resting energy expenditure: Evaluation of applicability in adolescents

We previously derived a cellular level approach for a whole-body resting energy expenditure (REE) prediction model by using organ and tissue mass measured by magnetic resonance imaging (MRI) combined with their individual cellularity and assumed stable-specific resting metabolic rates. Although this approach predicts REE well in both young and elderly adults, there were no studies in adolescents that specifically evaluated REE in relation to organ-tissue mass. It is unclear whether the approach can be applied to rapidly growing adolescents. The aim of the present study was to evaluate the applicability of the previous developed REE prediction model in adolescents, and to compare its applicability in young and elderly adults. Specifically, we tested the hypothesis that measured REE can be predicted from a combination of individual organ and tissue mass and their related cellularity. This was a 2-year longitudinal investigation. Twenty healthy male subjects with a mean age of 14.7 years had REE, organ and tissue mass, body cell mass, and fat-free mass (FFM) measured by indirect calorimetry, whole-body MRI, whole-body (40)K counting and dual-energy X-ray absorptiometry, respectively. The predicted REE (REEp; mean +/- SD, 1,487 +/- 238 kcal/day) was correlated with the measured REE (REEm, 1,606 +/- 237 kcal/day, r = 0.76, P < 0.001). The mean difference (118 +/- 165 kcal/day) between REEm and REEp was significant (P = 0.0047), accounting for 7.3% of REEm for the entire group. The present study, the first of its type in adolescents, does not support the applicability of the organ-tissue-based REE prediction model during rapid adolescent growth. A modified general REE prediction model is thus suggested which may account for the higher REE/FFM ratio observed in adolescents.

Tyrosine requirement during the rapid catch-up growth phase of recovery from severe childhood undernutrition

The requirement for aromatic amino acids during the rapid catch-up in weight phase of recovery from severe childhood undernutrition (SCU) is not clearly established. As a first step, the present study aimed to estimate the tyrosine requirement of children with SCU during the catch-up growth phase of nutritional rehabilitation using a diet enriched in energy and proteins. Tyrosine requirement was calculated from the rate of excretion of 13CO2 (F 13CO2) during [13C]phenylalanine infusion in thirteen children with SCU, five females and eight males, at about 19 d after admission when the subjects were considered to have entered their rapid catch-up growth phase and were consuming 627·3 kJ and about 3·5 g protein/kg per d. Measurements of F 13CO2 during [13C]phenylalanine infusion were made on two separate days with a 1 d interval. Three measurements at tyrosine intakes of 48, 71 and 95 mg/kg per d were performed on experimental day 1 and measurements at tyrosine intakes of 148, 195 and 241 mg/kg per d were performed on experimental day 2. An estimate of the mean requirement was derived by breakpoint analysis with a two-phase linear regression cross-over model. The breakpoint, which represents an estimate of the mean tyrosine requirement, is a value of 99 mg/kg per d when the children were growing at about 15 g/kg per d. The result indicates that the mean requirement for tyrosine during the catch-up growth phase of SCU is about 99 mg/kg per d under similar conditions to the present study.

Proposed Recommended Nutrient Densities for Moderately Malnourished Children

Recommended Nutrient Intakes (RNIs) are set for healthy individuals living in clean environments. There are no generally accepted RNIs for those with moderate malnutrition, wasting, and stunting, who live in poor environments. Two sets of recommendations are made for the dietary intake of 30 essential nutrients in children with moderate malnutrition who require accelerated growth to regain normality: first, for those moderately malnourished children who will receive specially formulated foods and diets; and second, for those who are to take mixtures of locally available foods over a longer term to treat or prevent moderate stunting and wasting. Because of the change in definition of severe malnutrition, much of the older literature is pertinent to the moderately wasted or stunted child. A factorial approach has been used in deriving the recommendations for both functional, protective nutrients (type I) and growth nutrients (type II).

Effect of dietary adherence with or without exercise on weight loss: a mechanistic approach to a global problem

CONTEXT

Weight loss using low-calorie diets produces variable results, presumably due to a wide range of energy deficits and low-dietary adherence.

OBJECTIVE

Our objective was to quantify the relationship between dietary adherence, weight loss, and severity of caloric restriction.

DESIGN AND SETTING

Participants were randomized to diet only, diet-endurance training, or diet-resistance training until body mass index (BMI) was less than 25 kg/m(2).

PARTICIPANTS

Healthy overweight (BMI 27-30) premenopausal women (n = 141) were included in the study.

INTERVENTIONS

An 800-kcal/d(-1) diet was provided, and the exercise groups were engaged in three sessions per week.

MAIN OUTCOMES

Dietary adherence, calculated from total energy expenditure determined by doubly labeled water measurements and dual-energy x-ray absorptiometry body composition changes, and degree of caloric restriction were determined.

RESULTS

All groups had similar weight loss (approximately 12.1 +/- 2.5 kg) and length of time to reach target BMI (approximately 158 +/- 70 d). Caloric restriction averaged 59 +/- 9%, and adherence to diet was 73 +/- 34%. Adherence to diet was inversely associated to days to reach target BMI (r = -0.687; P < 0.01) and caloric restriction (r = -0.349; P < 0.01). Association between adherence to diet and percent weight lost as fat was positive for the diet-endurance training (r = 0.364; P < 0.05) but negatively correlated for the diet-only group (r = -0.387; P < 0.05).

CONCLUSIONS

Dietary adherence is strongly associated with rates of weight loss and adversely affected by the severity of caloric restriction. Weight loss programs should consider moderate caloric restriction relative to estimates of energy requirements, rather than generic low-calorie diets.

Investigation of the cause of readmission to the intensive care unit for patients with lung edema or atelectasis

PURPOSE

For patients with acute respiratory failure due to lung edema or atelectasis, Surplus lung water that is not removed during an initial stay in the Intensive Care Unit (ICU) may be related to early ICU readmission. Therefore, we performed a retrospective study of patient management during the first ICU stay for such patients.

MATERIALS AND METHODS

Of 1,835 patients who were admitted to the ICU in the 36 months from January, 2003 to December, 2005, 141 were patients readmitted, and the reason for readmission was lung edema or atelectasis in 21 patients. For these 21 patients, correlations were investigated between body weight gain at the time of initial ICU discharge (weight upon discharge from the ICU / weight when entering the ICU) and the time to ICU readmission, between body weight gain and the P/F ratio at ICU readmission, between the R/E ratio (the period using a respirator (R) / the length of the ICU stay after extubation (E)) and the time to ICU readmission, between the R/E ratio and body weight gain, and between body weight gain until extubation and the time to extubation.

RESULTS

A negative linear relationship was found between body weight gain at the time of initial ICU discharge and the time to ICU readmission, and between body weight gain at the time of ICU discharge and the P/F ratio at ICU readmission. If body weight had increased by more than 10% at ICU discharge or the P/F ratio was below 150, readmission to the ICU within three days was likely. Patients with a large R/E ratio, a large body weight gain, and a worsening P/F ratio immediately after ICU discharge were likely to be readmitted soon to the ICU. Loss of body weight during the period of respirator support led to early extubation, since a positive correlation was found between the time to extubation and body weight gain.

CONCLUSION

Fluid management failure during the first ICU stay might cause ICU readmission for patients who had lung edema or atelectasis. Therefore, a key to the prevention of ICU readmission is to ensure complete recovery from lung failure before the initial ICU discharge. Strict water management is crucial based on body weight measurement and removal of excess lung water is essential. In addition, an apparent improvement in respiratory state may be due to respiratory support, and such an improvement should be viewed cautiously. Loss of weight at the refilling stage of transfusion prevents ICU readmission and may decrease the length of the ICU stay.

Energy imbalance underlying the development of childhood obesity

OBJECTIVE

To develop a model based on empirical data and human energetics to predict the total energy cost of weight gain and obligatory increase in energy intake and/or decrease in physical activity level associated with weight gain in children and adolescents.

RESEARCH METHODS AND PROCEDURES

One-year changes in weight and body composition and basal metabolic rate (BMR) were measured in 488 Hispanic children and adolescents. Fat-free mass (FFM) and fat mass (FM) were measured by DXA and BMR by calorimetry. Model specifications include the following: body mass (BM) = FFM + FM, each with a specific energy content, cff (1.07 kcal/g FFM) and cf (9.25 kcal/g FM), basal energy expenditure (EE), kff and kf, and energetic conversion efficiency, eff (0.42) for FFM and ef (0.85) for FM. Total energy cost of weight gain is equal to the sum of energy storage, EE associated with increased BM, conversion energy (CE), and diet-induced EE (DIEE).

RESULTS

Sex- and Tanner stage-specific values are indicated for the basal EE of FFM (kff) and the fat fraction in added tissue (fr). Total energy cost of weight gain is partitioned into energy storage (24% to 36%), increase in EE (40% to 57%), CE (8% to 13%), and DIEE (10%). Observed median (10th to 90th percentile) weight gain of 6.1 kg/yr (2.4 to 11.4 kg/yr) corresponds at physical activity level (PAL) = 1.5, 1.75, and 2.0 to a total energy cost of weight gain of 244 (93 to 448 kcal/d), 267 (101 to 485 kcal/d), and 290 kcal/d (110 to 527 kcal/d), respectively, and to a total energy intake of 2695 (1890 to 3730), 3127 (2191 to 4335), and 3551 (2487 to 4930) kcal/d, respectively. If weight gain is caused by a change in PAL alone and PAL(0) = 1.5 at baseline t = 0, the model indicates a drop in PAL of 0.22 (0.08 to 0.34) units, which is equivalent to 60 (18 to 105) min/d of walking at 2.5 mph.

DISCUSSION

Halting the development or progression of childhood obesity, as observed in these Hispanic children and adolescents, by counteracting its total energy costs will require a sizable decrease in energy intake and/or reciprocal increase in physical activity.

Fatty acid signatures of stomach oil and adipose tissue of northern fulmars (Fulmarus glacialis) in Alaska: implications for diet analysis of Procellariiform birds

Procellariiforms are unique among seabirds in storing dietary lipids in both adipose tissue and stomach oil. Thus, both lipid sources are potentially useful for trophic studies using fatty acid (FA) signatures. However, little is known about the relationship between FA signatures in stomach oil and adipose tissue of individuals or whether these signatures provide similar information about diet and physiology. We compared the FA composition of stomach oil and adipose tissue biopsies of individual northern fulmars (N = 101) breeding at three major colonies in Alaska. Fatty acid signatures differed significantly between the two lipid sources, reflecting differences in dietary time scales, metabolic processing, or both. However, these signatures exhibited a relatively consistent relationship between individuals, such that the two lipid sources provided a similar ability to distinguish foraging differences among individuals and colonies. Our results, including the exclusive presence of dietary wax esters in stomach oil but not adipose tissue, are consistent with the notion that stomach oil FA signatures represent lipids retained from prey consumed during recent foraging and reflect little metabolic processing, whereas adipose tissue FA signatures represent a longer-term integration of dietary intake. Our study illustrates the potential for elucidating short- versus longer-term diet information in Procellariiform birds using different lipid sources.

Role of huddling on the energetic of growth in a newborn altricial mammal

Huddling is considered as a social strategy to reduce thermal stress and promote growth in newborn altricial mammals. So far, the role of huddling on the allocation of saved energy has not been quantified nor have the related impacts on body temperature rhythms. To determine the energy partitioning of rabbit pups either raised alone or in groups of eight, four, or two individuals, when thermoregulatory inefficient (TI) and efficient (TE), we first investigated their total energy expenditure and body composition. We then monitored body temperature and activity rhythms to test whether huddling may impact these rhythms, centered on the suckling event. Pups in a group of eight utilized 40% less energy for thermogenesis when TI than did pups alone and 32% less energy when TE. Pups in groups of eight and four had significantly lower thermoregulatory costs in the TI period, whereas pups in groups of two, four, and eight had lower costs during the TE period. Huddling pups could therefore channel the energy saved into processes of growth and accrued more fat mass (on average 4.5 +/- 1.4 g) than isolated pups, which lost 0.7 g of fat. Pups in groups of four and eight had a body temperature significantly higher by 0.8 degrees C than pups in groups of two and one when TI, whereas no more differences were noted when the TE period was reached. Moreover, pups alone showed an endogenous circadian body temperature rhythm that differed when compared with that of huddling pups, with no rise before suckling. Thus huddling enables pups to invest the saved energy into growth and to regulate their body temperature to be more competitive during nursing, particularly at the early time when they are TI.

Energy requirements of children and adolescents

Total energy expenditure (TEE) was calculated at 1–18 years of age from measurements with doubly labelled water (DLW) in 483 boys and 646 girls, and heart rate monitoring (HRM) in 318 boys and 162 girls. Studies on obese, underweight and stunted groups were not included. TEE of populations with different lifestyles was estimated by factorial calculations in 42 studies on time allocation involving 1982 boys and 1969 girls in developed industrialised countries, and 1236 boys and 1116 girls in developing countries. Quadratic polynomial models were best to predict TEE in boys (TEE(MJ day−1) = 1.298 + 0.265 kg − 0.0011 kg2, r = 0.982, SEE = 0.518) and girls (TEE(MJ day−1) = 1.102 + 0.273 kg − 0.0019 kg2, r = 0.955, SEE = 0.650). TEE at 1–2 years was reduced by 7% based on DLW measurements and TEE estimates of infants. Energy requirements (ER) were calculated adding 8.6 kJ (2 kcal) for each gram of weight gained during growth. Compared with the 1985 FAO/WHO/UNU values1, ER were 18–20% lower from 1 to 7 years of age, 12% lower for boys and 5% lower for girls at 7–10 years, and 12% higher for either gender from 12 years onwards. Differences between industrialised and developing countries, the variance in DLW and HRM studies, and the standard error of the estimate (SEE) of the quadratic predictive equations, suggested that ER should be adjusted after 5 years of age by ±15% in populations with more or less physical activity than an average lifestyle. Physical activity recommendations must accompany dietary recommendations in order to maintain optimal health and reduce the risk of diseases associated with sedentary lifestyles.

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.

Home based therapy for severe malnutrition with ready-to-use food

BACKGROUND

The standard treatment of severe malnutrition in Malawi often utilises prolonged inpatient care, and after discharge results in high rates of relapse.

AIMS

To test the hypothesis that the recovery rate, defined as catch-up growth such that weight-for-height z score >0 (WHZ, based on initial height) for ready-to-use food (RTUF) is greater than two other home based dietary regimens in the treatment of malnutrition.

METHODS

HIV negative children >1 year old discharged from the nutrition unit in Blantyre, Malawi were systematically allocated to one of three dietary regimens: RTUF, RTUF supplement, or blended maize/soy flour. RTUF and maize/soy flour provided 730 kJ/kg/day, while the RTUF supplement provided a fixed amount of energy, 2100 kJ/day. Children were followed fortnightly. Children completed the study when they reached WHZ >0, relapsed, or died. Outcomes were compared using a time-event model.

RESULTS

A total of 282 children were enrolled. Children receiving RTUF were more likely to reach WHZ >0 than those receiving RTUF supplement or maize/soy flour (95% v 78%, RR 1.2, 95% CI 1.1 to 1.3). The average weight gain was 5.2 g/kg/day in the RTUF group compared to 3.1 g/kg/day for the maize/soy and RTUF supplement groups. Six months later, 96% of all children that reached WHZ >0 were not wasted.

CONCLUSIONS

Home based therapy of malnutrition with RTUF was successful; further operational work is needed to implement this promising therapy.

Effects of Resistance Training on Older Adults

Using an integrative approach, this review highlights the benefits of resistance training toward improvements in functional status, health and quality of life among older adults. Sarcopenia (i.e. muscle atrophy) and loss of strength are known to occur with age. While its aetiology is poorly understood, the multifactorial sequelae of sarcopenia are well documented and present a major public health concern to our aging population, as both the quality of life and the likelihood of age-associated declines in health status are influenced. These age-related declines in health include decreased energy expenditure at rest and during exercise, and increased body fat and its accompanying increased dyslipidaemia and reduced insulin sensitivity. Quality of life is affected by reduced strength and endurance and increased difficulty in being physically active. Strength and muscle mass are increased following resistance training in older adults through a poorly understood series of events that appears to involve the recruitment of satellite cells to support hypertrophy of mature myofibres. Muscle quality (strength relative to muscle mass) also increases with resistance training in older adults possibly for a number of reasons, including increased ability to neurally activate motor units and increased high-energy phosphate availability. Resistance training in older adults also increases power, reduces the difficulty of performing daily tasks, enhances energy expenditure and body composition, and promotes participation in spontaneous physical activity. Impairment in strength development may result when aerobic training is added to resistance training but can be avoided with training limited to 3 days/week.

Body weight gain in free-living Pima Indians: effect of energy intake vs expenditure

BACKGROUND

Obesity results from a chronic imbalance between energy intake and energy expenditure. However, experimental evidence of the relative contribution of interindividual differences in energy intake and expenditure (resting or due to physical activity) to weight gain is limited.

OBJECTIVE

To assess prospectively the association between baseline measurements of daily energy metabolism and weight changes by studying free-living adult Pima Indians, one of the most obese populations in the world.

DESIGN

A study of the pathogenesis of obesity in the Pima Indians living in Southwestern Arizona. The participants were 92 nondiabetic Pima Indians (64M/28F, 35+/-12 y, 35+/-9% body fat; mean+/-s.d.). At baseline, free-living daily energy metabolism was assessed by doubly labeled water and resting metabolic rate (RMR) by indirect calorimetry. Data on changes in body weight (5.8+/-6.5 kg) over a follow-up period of 4+/-3 y were available in 74 (49M/25F) of the 92 subjects.

RESULTS

The baseline calculated total energy intake (r=0.25, P=0.028) and RMR (r=-0.28, P=0.016) were significantly associated with changes in body weight. The baseline energy expenditure due to physical activity was not associated with changes in body weight.

CONCLUSION

Using state-of-the-art methods to assess energy intake and expenditure in free-living conditions, we show for the first time that the baseline calculated total energy intake is a determinant of changes in body weight in Pima Indians. These data also confirm that a low RMR is a risk factor for weight gain in this population.

Resistance training and intra-abdominal adipose tissue in older men and women

PURPOSE

Little is known concerning the effects of resistance-exercise training (RT) on older adult's intra-abdominal adipose tissue (IAAT). The purpose of this study was to determine the effects of RT on fat distribution in 12 women and 14 men, aged 61-77 yr.

METHODS

Computed tomography IAAT and abdominal subcutaneous adipose tissue (SAT), densitometry-determined body composition, one-repetition maximum (1-RM), and isometric strength were measured before and after 25 wk of RT. Training consisted of two sets of 10 repetitions at 65-80% of 1-RM, three times each week.

RESULTS

There were similar increases in strength for both the men and women. Women improved 22% and 38% in the isometric strength test and 1-RM test, respectively, whereas the men improved 21% and 36%, respectively. A significant increase in fat-free mass (FFM) was found for both men and women. However, there was a significant gender x time interaction, which indicated that men increased FFM more than women (2.8 kg vs 1.0 kg, respectively). Similar decreases in fat mass (FM) were found for the men (1.8 kg) and women (1.7 kg). However, women lost a significant amount of IAAT (131 to 116 cm2), whereas the men did not (143 to 152 cm2). Similarly, women also lost a significant amount of SAT (254 to 239 cm2), but men did not (165 to 165 cm2).

CONCLUSION

Despite similar decreases in FM after a 25-wk RT program, older women lost significant amounts of IAAT and SAT, whereas the older men did not.

Pattern and cost of weight gain in previously obese women

Weight gain is common among postobese individuals, providing an opportunity to address the cost of weight regain on energy expenditure. We investigated the energy cost of weight regain over 1 yr in 28 women [age 39.5 +/- 1.3 (SE) yr; body mass index 24.2 +/- 0.5 kg/m(2)] with recent weight loss (>12 kg). Body composition, total energy expenditure (TEE) using doubly labeled water, resting metabolic rate (RMR), and thermic effect of a meal (TEM) were assessed at 0 and 12 mo. Metabolizable energy intake (MEI) was calculated from TEE and change in body composition. Fourteen women had a weight gain of 13.2 +/- 2.1 kg. Twelve-month cumulative excess MEI, calculated as the intake in excess of TEE at month 0, was 749 +/- 149 MJ. Of this, 462 +/- 83 MJ (62%) were stored as accrued tissue, and 287 +/- 72 MJ (38%) was increased TEE. Expressed per kilogram of body weight gain, the energy cost of weight gain was calculated to be 54.8 +/- 4.6 MJ/kg. Interestingly, weight regain time courses fell into three distinct patterns, possibly requiring varying countermeasures.

Free-living activity energy expenditure in women successful and unsuccessful at maintaining a normal body weight

BACKGROUND

Although physical inactivity is believed to contribute to the rising prevalence of obesity, the role and magnitude of its contribution to weight gain are unknown.

OBJECTIVE

We compared total free-living activity energy expenditure (AEE) and physical activity level in women successful and unsuccessful at maintaining a normal body weight.

DESIGN

Premenopausal, generally sedentary women were studied at their normal weight and 1 y later after no intervention. Two groups were identified on the basis of extreme weight changes: maintainers (n = 27) had a weight gain of less-than-or-equal 3% of their initial body weight ( less-than-or-equal 2 kg/y) and gainers (n = 20) had a weight gain of >10% (>6 kg/y). At baseline and follow-up, evaluations were conducted during 4 wk of diet-controlled, energy-balance conditions. Free-living AEE and physical activity were assessed with the use of doubly labeled water, exercise energy economy and muscle strength with the use of standardized exercise tests, and sleeping EE and substrate utilization with the use of chamber calorimetry.

RESULTS

Maintainers lost a mean (plus minusSD) of 0.5 plus minus 2.2 kg/y and gainers gained 9.5 plus minus 2.1 kg/y. Gainers had a lower AEE (P < 0.02), a lower physical activity level (P < 0.01), and less muscle strength (P < 0.001); these differences between groups remained significant from baseline to follow-up. Sleeping EE, exercise economy, and sleeping or 24-h substrate utilization were not significantly different between the 2 groups. A lower AEE in the gainers explained approximately 77% of their greater weight gain after 1 y.

CONCLUSION

The general US population should increase their daily physical activity levels to decrease the rising prevalence of obesity.

Energy expenditure in the extremely low-birth weight infant

Information about energy requirements of extremely low-birth weight infants is sparse, despite the rapidly improving survival rates of this population. Metabolizable energy intake can be estimated from energy balance studies and the percentage of caloric intake that is actually absorbed by these infants is approximately 87%. Data on energy expenditure in extremely premature infants is limited; however, energy expenditure has been shown to increase with postnatal age. Because both intake and expenditure are affected by multiple factors, there is significant variability in estimates of the energy requirements in extremely low-birth weight infants. At present, no valid recommendations can be made regarding optimal energy requirements for the extremely low-birth weight infant, except that their requirements probably exceed those of stable, growing very low-birth weight infants, currently estimated at 105 to 135 kcal.kg-1d-1.

Dietary protein, growth and urea kinetics in severely malnourished children and during recovery

The case mortality for severe malnutrition in childhood remains high, but established best approaches to treatment are not used in practice. The energy and protein content of the diet at different stages of treatment appears important, but remains controversial. The effect on growth, urea kinetics and the urinary excretion of 5-L-oxoproline was compared between a standard infant formula (HP group) provided in different quantities at each stage of treatment and a recommended dietary regimen, which differentiates the requirements of protein and energy during the acute phase of resuscitation (maintenance intake of energy and protein, relatively low protein to energy ratio, LP group) from those during the restoration of a weight deficit (energy and nutrient dense). The energy required to maintain weight was less in the HP than the LP group, but the HP group was not able to achieve as high an energy intake during repletion of wasting because of the high volume which would have had to be consumed. Compared to the LP group, in the HP group during catch-up growth there was significantly greater deposition of lean tissue and higher rates of urea production, hydrolysis and salvage of urea-nitrogen. These, together with higher rates of 5-L-oxoprolinuria, suggest a greater constraint of the formation of adequate amounts of nonessential amino acids, especially glycine, in the face of enhanced demands. Although more effective rehabilitation might be achieved using a standard formula, there is the need to determine the extent to which it might impose metabolic stress compared with the modified formulation.

Adipose tissue in human infancy and childhood: an evolutionary perspective

Humans diverge from most mammals, including nonhuman primates, by depositing significant quantities of body fat in utero and are consequently one of the fattest species on record at birth. While explanations for the fat layer of human neonates have commonly assumed that it serves as insulation to compensate for hairlessness, empirical support for this hypothesis is presently weak. Whether the tissue's abundance at birth and growth changes in adiposity during infancy and childhood might be explained in light of its role as energy buffer has not been assessed, and this possibility is explored through development of a model of fat function and growth centered on two related hypotheses. The first is that the greater adiposity of human neonates is at least partially explainable as an accompaniment of the enlarged human brain, which demands a larger energy reserve to ensure that its obligatory needs are met when the flow of resources from mother or other caretakers is disrupted. The second is that age-related changes in the likelihood of experiencing such disruption have influenced the pattern of investment in the tissue, reflected today in peak adiposity during infancy and a decline to a leaner childhood period. Nutritional disruption is common at birth and until lactation is established, during which time human newborns survive from fats deposited prenatally, suggesting one possible explanation for the early onset of fat deposition. At weaning, the transition from breast milk to supplemental foods and the parallel transition from maternal to endogenous immune protection interact to increase the frequency and impact of nutritional disruption, and this may help explain why newborns devote roughly 70% of growth expenditure to fat deposition during the early postnatal months. Evidence is presented that fat stores are mobilized during infections, hinting at one possible mechanism underlying the association between nutritional status and infectious morbidity and mortality among infants in nutritionally stressed human populations. Consistent with the proposed hypothesis, well-fed infants acquire peak fat reserves by an age of peak prevalence of malnutrition, infectious disease, and fat reserve depletion in less-buffered contexts, and childhood--characterized by minimal investment in the tissue--is a stage of reduced risk of energy stress. The model presented here foregrounds energy storage in adipose tissue as an important life-history strategy and a means to modify mortality risk during the nutritionally turbulent period of infancy.

Protein and energy requirements in healthy and ill paediatric patients

A reappraisal of available data, together with new studies, suggests that normal infants' energy and protein requirements might be substantially lower than previously estimated. For example, the safe level of protein intake would amount to only 10 g per day during the first 2 years of life and to about 12 g per day during the third. This has direct consequences for the management of malnourished children, particularly for defining an optimal protein:energy ratio. A reduced food intake has long been accepted as the main cause of malnutrition. However, evidence has accumulated suggesting that metabolic dysregulation may also play a part. This is particularly true for proteins. Net protein deposition in the growing child results from protein synthesis rates being higher than protein breakdown. However, this setting can be disrupted by a significant increase in protein breakdown in response to cytokines. This mechanism, which is found in acute as well as in chronic inflammatory processes, may lead to severe protein malnutrition and is not always amenable to nutritional support.

Effects of fasting and refeeding on body composition of captive gray wolves (Canis lupus)

We examined the effects of fasting and refeeding on body composition in 9 captive adult gray wolves, Canis lupus (6 males, 3 females), during May–June 1995. Body composition was estimated by the technique of tritiated water dilution. Wolves were immobilized and weighed, base-line blood samples were taken, tritiated water was injected, and additional blood samples were taken before fasting, after 10 d of fasting, and again after 2 d of refeeding. Male wolves lost 8% (P = 0.0001) and females lost 7% body mass (P = 0.01) during the 10 d. Males lost 54% of this mass in water, 28% in fat, and 18% in protein/ash; females lost 58% in water, 20% in fat, and 22% in protein/ash. Upon refeeding, male wolves consumed an average of 6.8 kg (15.3% body mass) of deer meat per day and females consumed 6.4 kg (18.7% body mass). All wolves regained their initial mass. Males regained 24% of this mass in water, 70% in fat, and 6% in protein/ash; females regained 35% in water, 51% in fat, and 14% in protein/ash. This study provided evidence that after prolonged fasting, captive wolves could quickly and efficiently regain lost body mass after refeeding.

Protein-energy interactions in the management of severemalnutrition

The three syndromes of childhood malnutrition are contrasted with respect to protein. It is concluded that stunting and wasting are the outcomes of protein deficiency, and that kwashiorkor is not due to protein deficiency, rather it is related to unopposed oxidant stress. Formula for the energy and protein requirements are derived and contour plots of the amounts needed to sustain high rates of weight gain at different body compositions generated. It is suggested that all nutrients be expressed with energy as the denominator. No more than 12.5% of protein energy is required to sustain maximum likely rates of weight gain. Using this approach to design a diet, high rates of weight gain are achieved under field conditions in refugee camps.

Nutritional management of failure to thrive

Failure to thrive, or failure to grow or gain weight, could have several causes that are reviewed in this article. Infant behaviors are discussed, together with nutritional management, catch-up growth, effects of nutritional rehabilitation on body composition, follow-up, and long-term prognosis.

Fat and cholesterol in the diet of infants and young children: implications for growth, development, and long-term health

Fat is necessary in the diets of infants and young children because of their extraordinary energy needs and limited dietary capacity. In addition, essential fatty acids provide the substrates for arachidonic acid, docosahexaenoic acid, and their metabolites. Deficiencies in the amounts of these long-chain fatty acids in the diet during infancy may affect the maturation of the central nervous system, including visual development and intelligence. Efforts to link the diet in infancy and early childhood to the development of chronic diseases in adulthood are hampered by a lack of supportive epidemiologic and clinical data. Serum cholesterol and lipid levels during childhood correlate only weakly with their levels at maturity. Studies in twins suggest that there is a large genetic component to serum lipid levels. Similarly, the correlation between obesity in early childhood and in adulthood is weak. Young children who receive fat-restricted diets in which fat accounts for 30% or less of their intake appear to grow normally but are more likely not to consume the recommended dietary allowances of many nutrients. Therefore fat should not be restricted in the diets of infants and young children. Restricting fat to approximately 30% of the calories consumed is reasonable after the age of 2 years, but the benefits of this recommendation remain to be proved.

Altered energy balance may account for growth failure in Rett syndrome

To determine whether alterations in energy balance account for growth failure in Rett syndrome, we measured dietary energy intakes, fecal fat losses, activity patterns, and sleeping as well as quietly and actively awake metabolic rates in Rett syndrome girls and healthy controls. Dietary energy intakes and fecal fat losses did not differ between the groups. Metabolic rates while sleeping and quietly awake were 23% lower (P < .05) in Rett syndrome girls than in controls; metabolic rates while actively awake did not differ between the groups. However, because of the 2.4-fold greater time (P < .001) spent in involuntary motor movement, energy expenditure associated with activity was twofold greater (P < .05) in Rett syndrome girls than in controls. Although total daily energy expenditure of the two groups did not differ significantly, energy balance was less positive in the Rett syndrome girls than in the controls. This small difference in energy balance, if sustained over months to years, is sufficient to account for growth failure in Rett syndrome girls.

Energy expenditure in congenital heart disease

Growth failure is a well recognised consequence of severe congenital heart disease. Total daily energy expenditure (TDEE) was investigated in eight infants with severe congenital heart disease to determine whether an increase in this parameter is an important factor in their failure to thrive, and to estimate the energy intake that would be required to allow normal growth. The infants were studied over a seven day period before surgery using the doubly labelled water method. Growth failure was evident; their mean age standardised body mass index was 80% of the expected value. Mean TDEE was 425 kJ/kg, significantly greater than in healthy infants (mean TDEE/kg SD score = +1.4; 95% confidence interval +0.27 to +2.57). In contrast, their energy intake was only 82% of the estimated average requirements. It was estimated that in early infancy a gross energy intake of 600 kJ/kg/day is required for normal growth in patients with congenital heart disease. This is unlikely to be achieved by energy supplements alone and early recourse to nasogastric feeding should be considered.

Assessment of total energy expenditure in free-living patients with cystic fibrosis

The increase in resting energy expenditure (REE) reported in patients with cystic fibrosis (CF) does not necessarily imply an increase in total energy expenditure (TEE). In this study REE was assessed with open-circuit indirect calorimetry, and free-living 24-hour TEE with the heart rate method. Thirteen patients with CF, aged 8 to 24 years, with adequate nutritional status and moderately decreased pulmonary function, were studied. They were compared with 13 healthy control subjects matched for gender, age, height, and nutritional status. Resting energy expenditure was higher in patients with CF (1512 +/- 88 kcal/day) than in control subjects (1339 +/- 76 kcal/day; p less than 0.01), whereas free-living 24-hour TEE (2345 +/- 127 kcal/day and 2358 +/- 256 kcal/day, respectively) and net mechanical work efficiency of walking on a treadmill (20.4 +/- 0.7% and 19.8 +/- 0.6%, respectively) were similar. Respiratory quotient was higher in patients with CF than in control subjects at rest (0.834 +/- 0.009 vs 0.797 +/- 0.008; p less than 0.05), and tended to remain so during physical exercise, indicating a higher contribution of carbohydrate oxidation to energy expenditure. We conclude that in free living conditions, patients with CF can compensate for their increase in REE by a reduction in spontaneous physical activities or other yet undefined mechanisms.

Energy expenditure and substrate utilization in the course of renutrition of malnourished children

Energy expenditure (EE) and substrate utilization in the course of renutrition of malnourished children is not well understood in children receiving total parenteral nutrition (TPN). The aim of this study was to evaluate, during protein-glucose renutrition, EE and substrate utilization and the relationship between EE and growth and/or protein metabolism. Seven malnourished children were studied during the first 3 weeks of TPN. Weight-for-height = 81.4 +/- 8.0%, with an initial weight of 4.5 +/- 3.3 kg. Caloric support was progressively increased according to a preestablished protocol. Every 7 days the following were determined: (1) EE at 3 different 3-hour intervals per day using an open circuit indirect calorimetric system, (2) anthropometrically defined fat free mass (FFM), and (3) 24-hour urinary 3-methylhistidine (3-M-His) and protein balance. Compared to initial values, EE increased 13% at day 7 and 36% at day 14. A negative relationship was found between the amount of perfused glucose and lipid utilization (r = -0.82; p less than 0.0001). EE per kilogram of total body FFM changes during renutrition were more than EE changes per kilogram of total body weight. There was a relationship between EE and weight gain (r = 0.62; p less than 0.005) and a positive relationship between EE and protein gain (r = 0.48; p = 0.012) and 3-M-His excretion (r = 0.51; p less than 0.026).(ABSTRACT TRUNCATED AT 250 WORDS)