Energy supplementation reverses changes in the basal metabolic rates of chronically undernourished individuals

Influence of nutritional status on basal metabolic rates among rural agriculturalists of Ngilo-Ilo, East Java

OBJECTIVES

Previous research has shown that tropical island populations have reduced basal metabolic rates (BMR) associated with the joint influences of heat stress and undernutrition. This study examines variation in BMR among an indigenous population of Indonesia, and compares these data with those collected from earlier studies in Indonesia.

METHODS

Anthropometric dimensions and BMR were measured on a sample of 35 Indonesian adults (28 men, 7 women) from the rural village of Ngilo-Ilo, East Java.

RESULTS

Mean measured BMRs (±SD) were 1433 ± 344 kcal/d in men and 1256 ±257 kcal/d in women, and were not significantly different from estimates using the FAO/WHO/UNU predictive questions. Underweight individuals (BMIs <18.5 kg/m² ) had BMRs that were 7.6% below predicted levels, while those with BMIs ≥18.5 kg/m² had BMRs that were 8.0% above predicted levels (P < .01). Underweight individuals also had significantly higher respiratory quotients (RQ = .94 vs. .89; P < .05), suggesting lower levels of fat oxidation. Compared to data from previous studies (1929-1979), men of the Ngilo-Ilo sample had similar BMIs (19.8 vs. 19.2 kg/m² ), but higher BMRs, after adjusting for age and body weight (+2.1% vs. -5.6%; P < .05).

CONCLUSIONS

Among the agriculturalists of Ngilo-Ilo, measured BMRs were low, but not significantly different from those predicted by the FAO/WHO/UNU equations. Among subjects of this sample and from earlier studies, poorer physical nutritional status was associated with reduced BMRs. These results suggest that chronic energy stress has consistently shaped metabolic function among Indonesian rural populations.

Energy expenditure in anorexia nervosa: can fat-free mass as measured by bioelectrical impedance predict energy expenditure in hospitalized patients?

Anorexia nervosa (AN) is associated with a reduced metabolically active fat-free mass (FFM) and basal metabolic rate (BMR). Excessive refeeding results in major fat deposition which is not well tolerated by patients. Prediction of BMR is, therefore, a clinical issue during refeeding, but measurement by indirect calorimetry is time-consuming and not widely available. The study aim was to determine if and when BMR could be estimated from prediction formulas based on FFM derived from bioelectrical impedance analysis (BIA) in AN patients during refeeding. Indirect calorimetry and BIA were prospectively measured bi-weekly in 9 AN patients (body mass index 13.7 +/- 0.5 kg/m2) for 10 weeks of refeeding. Initial BMR was 969 +/- 46.7 kcal/d and 27.7 +/- 1.4 kcal/kg FFM, and at week 10 increased to 1360 +/- 44.6 kcal/d and 35.8 +/- 0.8 kcal/kg FFM. While correlations improved with increasing weight, FFM and body mass index, prediction formulas are insufficient to permit prediction of BMR based on weight or FFM, even after 10 weeks of refeeding. To allow for optimal nutritional support, indirect calorimetry measurements may be useful in the early weeks of refeeding because of a large variability of basal metabolic rate between patients.

The conceptual framework for estimating food energy requirement

Objective

In anticipation of the revision of the 1985 Food and Agricultural Organization/World Health Organization/United Nations University (FAO/ WHO/UNU) Expert Consultation Report on ‘Energy and Protein Requirements’, recent scientific knowledge on the principles underlying the estimation of energy requirement is reviewed.

Design

This paper carries out a historical review of the scientific rationale adopted by previous FAO/WHO technical reports on energy requirement, discusses the concepts used in assessing basal metabolic rate (BMR), energy expenditure, physical activity level (PAL), and examines current controversial areas. Recommendations and areas of future research are presented.

Conclusions

The database of the BMR predictive equations developed by the 1985 FAO/WHO/UNU Expert Consultation Report on Energy and Protein Requirements needs updating and expansion, applying strict and transparent selection criteria. The existence of an ethnic/tropical factor capable of affecting BMR is not supported by the available evidence. The factorial approach for the calculation of energy requirement, as set out in the 1985 report, should be retained. The estimate should have a normative rather than a prescriptive nature, except for the allowance provided for extra physical activity for sedentary populations, and for the prevention of non-communicable chronic diseases. The estimate of energy requirement of children below the age of 10 years should be made on the basis of energy expenditure rather than energy intake. The evidence of the existence of an ethnic/tropical factor is conflicting and no plausible mechanism has as yet been put forward.

Consequences of inadequate food energy and negative energy balance in humans

Energy deficiency is probably best measured in adults by the body mass index (BMI). Acute energy deficiency (AED) is associated with body weight loss, along with changes in body composition, as well as a reduced BMR and physical activity. Chronic energy deficiency (CED) is an inadequacy in food to which individuals adapt, at some cost. Individuals with this have never 'lost' weight: they have simply grown less. They adapt to the decreased food energy by reductions in their total energy expenditure (TEE), linked mainly to a lower body size, and to their physical activity. It seems unlikely that enhanced metabolic efficiency contributes substantially to energy saving in CED. Supplementation of energy deficient individuals is accompanied by significant fat deposition; this may have deleterious consequences. Women in many developing countries achieve a successful outcome to pregnancy in spite of being chronically undernourished. Reductions in basal metabolism and behavioural changes in the form of diminished physical activity could meet most of the extra energy needed for pregnancy. Milk energy output is maintained within the expected range in undernourished lactating mothers. Energy deficiency in children is best measured by height-for-age for stunting, and weight-for-height for wasting. Deficits in behavioural and functional parameters in children exist with undernutrition, and can be reduced by early nutritional supplementation along with the appropriate environment.

The effect of severe undernutrition and subsequent refeeding on whole-body metabolism and protein synthesis in human subjects

BACKGROUND

To determine the consequences of severe undernutrition and refeeding on whole-body metabolism and protein synthesis.

METHODS

Respiratory quotient (RQ), resting energy expenditure (REE), and whole-body protein synthesis (WBPS) were assessed in undernourished patients, with anorexia nervosa (n = 8) or with coexistent disease (n = 17). Results were compared with 17 healthy controls. Six anorexic patients and 13 disease patients consented to study after nutrition support.

RESULTS

Mean body mass index was 12.46 +/- 0.53 kg/m2 in the anorexia patients and 13.81 +/- 0.40 kg/m2 in the disease patients (controls 23.71 +/- 0.72 kg/m2; p < .001). Compared with controls, RQ was similar in anorexia patients (0.85 +/- 0.05 vs 0.90 +/- 0.05) but lower in the disease patients (0.76 +/- 0.03 vs 0.90 +/- 0.05; p = .02). REE was lower in the patients (anorexia 1058 +/- 134.0 kcal/d, disease 1189 +/- 101.4 kcal/d vs 1828 +/- 89.76 kcal/d; p < .001); however, expressed as kcal/kg/d, it was higher (anorexia 32.17 +/- 4.25, disease 31.30 +/- 2.14 vs 25.07 +/- 1.00; p < .05). WBPS was lower in the patients (anorexia 140.9 +/- 10.54 g/d, disease 119.8 +/- 8.57 g/d vs 305.0 +/- 21.64 g/d; p < .001); however, when expressed as g/kg/d, the anorexia patients were similar to controls, whereas the disease patients were lower (3.11 +/- 0.24 vs 4.27 +/- 0.32; p < .05). Refeeding increased RQ in the disease patients (0.84 +/- 0.03 vs 0.76 +/- 0.03; p < .05), and normalized REE (anorexia 27.65 +/- 3.05 kcal/kg/d, disease 28.90 +/- 1.85 kcal/kg/d). WBPS increased in the disease patients (173.6 +/- 16.38 g/d vs 116.5 +/- 10.15 g/d; p < .01).

CONCLUSIONS

Undernutrition is associated with increased REE (kcal/kg/d). Reduction in RQ and protein synthesis (g/kg/d) was evident in those patients with coexistent disease. Refeeding resulted in normalization of RQ, REE (kcal/kg/d), and protein synthesis (g/kg/d).

Iron and energy supplementation improves the physical work capacity of female college students

A nutritionally controlled study was conducted on two groups of 15 female college students aged 16 to 20 years, selected from Punjab Agricultural University, Ludhiana, Punjab, India. The girls were either anemic (hemoglobin 7.7 g/dl) but energy adequate (AEA), or anemic (hemoglobin 7.4 g/dl) and energy deficient (AED). The AEA group was given iron supplementation (60 mg iron/day) for 6 to 9 months along with 100 mg of ascorbic acid, and the AED group was given iron as well as energy supplementation for 3 months. There was a significant (p < .01) increase in weight, body mass index, mid-upper-arm circumference, and body fat in the AED group after iron-energy supplementation. Hemoglobin, serum iron, transferrin saturation, total iron-binding capacity, and unsaturated iron-binding capacity were below normal in both groups; however, after iron and iron-energy supplementation, there was a significant (p < .01) increase, and these indices were in the normal range. There was a significant (p < .01) increase in exercise time and maximum work load tolerance after iron and iron-energy supplementation. Combined energy and iron deficiency had a greater adverse effect on physical work capacity than energy or iron deficiency alone.

Basal metabolic rate in anorexia nervosa: relation to body composition and leptin concentrations

BACKGROUND

Leptin is thought to represent a peripheral signal involved in the regulation of energy balance. Its action has been studied in animals and obese subjects. Little is known about leptin's role during negative energy balance.

OBJECTIVE

The objective was to evaluate the relation between energy turnover, body composition, and plasma leptin concentrations in anorexia nervosa (AN).

DESIGN

Sixteen weight-stable women with AN were compared with 22 control subjects and 14 rehabilitated AN patients (R-AN). Basal metabolic rate (BMR) was measured by indirect calorimetry; fat-free mass (FFM) and fat mass (FM) were calculated according to a 4-compartment model. Plasma leptin was determined by radioimmunoassay.

RESULTS

The BMR of AN patients (2.73 +/- 0.37 kJ/min) was significantly lower than that of control subjects (3.45 +/- 0.34 kJ/min) (P < 0.001), even after adjustment for FFM (2.92 +/- 0.33 kJ/min in AN patients and 3.30 +/- 0.26 kJ/min in control subjects; P < 0.004). Plasma leptin concentrations in AN patients were 76% lower than in control subjects, even after body fat was controlled for. In R-AN patients, BMR was not significantly different from that of control subjects and leptin concentrations were generally close to normal. Plasma leptin concentrations correlated significantly with FM (r(2) = 0.53, P < 0.0000) and BMR, even after adjustment for FFM (r(2) = 0.21, P < 0.0003).

CONCLUSIONS

BMR and plasma leptin concentrations are depressed in patients with AN; this is not explained by body-composition changes. The relation between leptin and BMR suggests that leptin plays a role in the energy sparing response to exposure to chronic energy deficiency. The return of BMR to normal and the significant increase in leptin concentrations in R-AN patients suggests a full reversibility of this adaptation mechanism.

The prevalence and consequences of subclinical eating disorders in female athletes

A growing body of evidence suggests that the prevalence of eating disorders and excessive concerns regarding body weight in certain subpopulations of female athletes are increasing. The pressure on female athletes to improve their performances and physiques, coupled with the general sociocultural demand placed on all women to be thin, often results in attempts to achieve unrealistic body size and body weight goals. For some female athletes the pressure to achieve and maintain a low body weight leads to potentially harmful patterns of restrictive eating or chronic dieting. This paper seeks to further delineate the characteristics of a recently identified subclinical eating disorder in female athletes: anorexia athletica. Research studies that support the existence of subclinical eating disorders will be reviewed. In addition, the possible physiological and psychological consequences of subclinical eating disorders will be explored.

Thermic effect of a meal. 3. Effect of dietary supplementation in chronically undernourished human subjects

Five apparently healthy, chronically undernourished (UN) male volunteers aged between 18 and 30 years were studied before and after 12 weeks of dietary supplementation. The thermic effect of a meal (TEM) was measured over a period of 6 h using a ventilated-hood system. Results indicated a significant increase in body-weight after supplementation due to increases in body fat and fat-free mass (FFM) in the proportion of 69% and 31% respectively. The basal metabolic rates (BMR) measured post supplementation were significantly higher in absolute terms, with a trend towards higher values when adjusted for the changes in FFM. TEM responses measured after 12 weeks of supplementation were significantly lower when expressed either in absolute terms (presupplementation 227.0 kJ v. post supplementation 193.5 kJ), or as a percentage of the energy density of the meal (9.1% v. 7.7%). This lower TEM was reciprocal to the changes in the BMR (r -0.86). The post-meal total energy output (PMTEO) was, however, not significantly different after 12 weeks of dietary supplementation. The unchanged PMTEO would indicate an unaltered 'thermogenic capacity', following supplementation, in these chronically undernourished subjects. These results confirm our earlier conclusion that, in chronic undernutrition, the thermic response to a meal may not contribute to any energy saving.