Metabolic adaptation to caloric restriction and subsequent refeeding: the Minnesota Starvation Experiment revisited.

Background: Adaptive thermogenesis (AT) is the fat-free mass (FFM)-independent reduction of resting energy expenditure (REE) to caloric restriction (CR). AT attenuates weight loss and favors weight regain. Its variance, dynamics, and control remain obscure.

Sarcopenia and the analysis of body composition.

Reduction of lean mass is a primary body composition change associated with aging. Because many factors contribute to lean mass reduction, the problem has been given various names depending on the proposed cause, such as "age-related sarcopenia," "dynapenia," "myopenia," "sarcopenic obesity," or simply "sarcopenia." There is currently no consensus on how to best diagnose the reduction of lean mass and its consequences on health.

What makes a BIA equation unique? Validity of eight-electrode multifrequency BIA to estimate body composition in a healthy adult population.

Background/objectives: The validity of bioelectrical impedance analysis (BIA) for body composition analysis is limited by assumptions relating to body shape. Improvement in BIA technology could overcome these limitations and reduce the population specificity of the BIA algorithm.

Subjects/methods: BIA equations for the prediction of fat-free mass (FFM), total body water (TBW) and extracellular water (ECW) were generated from data obtained on 124 Caucasians (body mass index 18.

Bone mineral density in elite adolescent female figure skaters.

Unlabelled: Elite adolescent figure skaters must accommodate both the physical demands of competitive training and the accelerated rate of bone growth that is associated with adolescence, in this sport that emphasizes leanness. Although, these athletes apparently have sufficient osteogenic stimuli to mitigate the effects of possible low energy availability on bone health, the extent or magnitude of bone accrual also varies with training effects, which differ among skater disciplines.

Purpose: We studied differences in total and regional bone mineral density in 36 nationally ranked skaters among 3 skater disciplines: single, pairs, and dancers.

Water homeostasis, frailty and cognitive function in the nursing home.

Objective: - To develop and test a practical clinical method to assess frailty in nursing homes; - To investigate the relationship between cognitive status of the elderly and the balance between water compartments of their body composition.

Design And Subjects: Cross-sectional study, conducted at two nursing homes in Boston-MA.

Methods: Body mass and height (Ht) were evaluated to calculate BMI (body mass index, in Kg/m²).

Growth deceleration and restoration after serious burn injury.

There is a common perception that burned children are at risk for growth deceleration. However, because the prevalence, duration, and degree of this stereotypic growth are poorly described, making informed decisions about treatment is difficult. This article describes the natural history of growth after burn injury, according to the findings of a retrospective review conducted in a regional pediatric burn center.

Body water in children during recovery from severe burn injury using a combined tracer dilution method.

Useful information about hydration and the size of the body cell mass (BCM) can be obtained by monitoring changes in the amount of total body water (TBW) and its components, extracellular water (ECW) and intracellular water (ICW). A combined tracer dilution method with deuterium to measure TBW and bromide to measure ECW was used to assess changes in ICW (as a proxy for the BCM) and in the ECW/ICW ratio (an indicator of water distribution) over the course of recovery in nine severely burned children. During the acute phase of recovery, ICW losses averaged (mean +/- SD) 2.

Energy expenditure is very high in extremely obese women.

To test the hypothesis that total energy expenditure (TEE) and resting energy expenditure (REE) are low in extremely obese individuals, factors that could contribute to maintenance of excess weight, a cross-sectional study was conducted in 30 weight stable, extremely obese women [BMI (mean +/- SEM) 48.9 +/- 1.7 kg/m(2)].

Use of D-T-produced fast neutrons for in vivo body composition analysis: a reference method for nutritional assessment in the elderly.

Body composition has become the main outcome of many nutritional intervention studies including osteoporosis, malnutrition, obesity, AIDS, and aging. Traditional indirect body composition methods developed with healthy young adults do not apply to the elderly or diseased. Fast neutron activation (for N and P) and neutron inelastic scattering (for C and O) are used to assess in vivo elements characteristic of specific body compartments.

Long-term changes in energy expenditure and body composition after massive weight loss induced by gastric bypass surgery.

Background: Little is known about the determinants of individual variability in body weight and fat loss after gastric bypass surgery or about the effects of massive weight loss induced by this surgery on energy requirements.

Objectives: The objectives were to determine changes in energy expenditure and body composition with weight loss induced by gastric bypass surgery and to identify presurgery predictors of weight loss.

Design: Thirty extremely obese women and men with a mean (+/- SD) age of 39.

Sodium bromide by instrumental neutron activation analysis quantifies change in extracellular water space with wound closure in severely burned children.

Background: The ability to measure extracellular water (ECW) in critically ill patients can significantly enhance current methods of assessing fluid homeostasis, body composition, and response to nutritional therapy. We measured corrected bromide space to determine change in ECW with wound closure among acutely burned children.

Methods: Fifteen children with burns over 30% of their total body surface area had their ECW determined following hemodynamic stabilization and when wound closure was complete.

Body composition assessment in extreme obesity and after massive weight loss induced by gastric bypass surgery.

Body composition methods were examined in 20 women [body mass index (BMI) 48.7 +/- 8.8 kg/m(2)] before and after weight loss [-44.

Cachexia in rheumatoid arthritis is not explained by decreased growth hormone secretion.

Objective: Patients with rheumatoid arthritis (RA) lose body cell mass (BCM) by unknown mechanisms. Since the loss of BCM in normal aging individuals parallels the characteristic age-related decline in growth hormone (GH) secretion, this study was carried out to determine whether further decreased GH secretion plays a role in the pathogenesis of this loss of BCM in RA patients, termed "rheumatoid cachexia."

Methods: GH secretory kinetics were determined by deconvolution analysis in 16 patients with RA and 17 healthy controls matched for age (mean +/- SD 45.

Resistance training to counteract the catabolism of a low-protein diet in patients with chronic renal insufficiency. A randomized, controlled trial.

Background: Chronic renal insufficiency leads to muscle wasting, which may be exacerbated by low-protein diets prescribed to delay disease progression. Resistance training increases protein utilization and muscle mass.

Objective: To determine the efficacy of resistance training in improving protein utilization and muscle mass in patients with chronic renal insufficiency treated with a low-protein diet.

Older men and women efficiently absorb vitamin B-12 from milk and fortified bread.

Nothing is directly known about the bioavailability of vitamin B-12 from dairy products or fortified grain products. We directly studied vitamin B-12 absorption from water, milk and fortified bread in adult subjects using (58)Co-labeled vitamin B-12 and a whole body gamma-ray counter/spectrophotometer. Sixteen healthy men and women over the age of 60 y with normal serum levels of vitamin B-12 and normal basal gastric acid secretion were studied.

The effect of gender and body composition method on the apparent decline in lean mass-adjusted resting metabolic rate with age.

Background: Declining resting energy expenditure (REE) is a hallmark of normal aging, but the cause of this decline remains controversial. Some, but not all, studies have shown that the decline in REE with age is eliminated after adjustment for fat-free mass (FFM).

Methods: We examined the effect of four body composition methods used to assess FFM (underwater weighing [UWW], bioimpedance analysis [BIA], tritium dilution, and total body potassium [TBK]) on the relationship between REE and age in 30 healthy men and 101 healthy women aged 18 to 87 years.

In vivo elemental partition analysis using fast neutrons. A tool for testing the efficacy of new clinical interventions.

The nutritional status of patients can be evaluated by monitoring changes in body composition, including depletion of protein and muscle; distribution of adipose tissue; and changes in hydration status, and bone or cell mass. Fast neutron activation (for N and P) and neutron inelastic scattering (for C and O) are used to assess in vivo elements characteristic of specific body compartments. Nonbone phosphorus for muscle is measured by the 31P(n,alpha)28Al reaction, and nitrogen for protein via the (n,2n) fast neutron reaction.

Neutron activation analysis determination of body composition.

The nutritional status of patients can be evaluated by monitoring changes in body composition, including the depletion of protein and muscle, adipose tissue distribution and changes in hydration status, bone or cell mass. Neutron activation analysis is a unique reference tool for the in-vivo determination of body composition. In this review we describe the recent changes in the field that followed the advent of new portable generators of fast neutrons, capable of performing elemental analysis in the clinical environment.

Bone mineral measurements: a comparison of delayed gamma neutron activation, dual-energy X-ray absorptiometry and direct chemical analysis.

A system in vitro consisting of a femur from a cadaver and soft-tissue equivalent material was used to test the agreement between several techniques for measuring bone mineral. Calcium values measured by delayed gamma neutron activation (DGNA) and bone mineral content (BMC) by Lunar, Hologic and Norland dual-energy X-ray absorptiometers (DXA) were compared with calcium and ash content determined by direct chemical analysis. To assess the effect of soft-tissue thickness on measurements of bone mineral, we had three phantom configurations ranging from 15.

Insulin-like growth factor I in skeletal muscle after weight-lifting exercise in frail elders.

To assess muscle remodeling and functional adaptation to exercise and diet interventions, 26 men and women aged 72-98 yr underwent a vastus lateralis biopsy before and after placebo control condition, and progressive resistance training, multinutrient supplementation, or both. Type II atrophy, Z band, and myofibril damage were present at baseline. Combined weight lifting and nutritional supplementation increased strength by 257 +/- 62% (P = 0.

Body composition in children and adults by air displacement plethysmography.

Objectives: Air displacement plethysmography (ADP) may provide a partial alternative to body density (Bd) and therefore body composition measurement compared to conventional hydrodensitometry (Hd) in children. As there are no evaluation studies of ADP in children, this study had a two-fold objective: to compare Bd estimates by ADP and Hd; and to compare fat estimates by both ADP and Hd to fat estimates by another reference method, dual energy X-ray absorptiometry (DXA).

Setting: Obesity Research Center, St.

Nutritional alterations and the effect of fish oil supplementation in dogs with heart failure.

Alterations in body composition and nutritional status are common in humans with heart failure and are related, in part, to increases in cytokine concentrations. Cytokines have not been studied previously in dogs with naturally occurring cardiac disease nor has fish oil administration been used in this population to decrease cytokine production. The purposes of this study were to characterize nutritional and cytokine alterations in dogs with heart failure and to test the ability of fish oil to reduce cytokines and improve clinical outcome.

The relationship between growth hormone kinetics and sarcopenia in postmenopausal women: the role of fat mass and leptin.

Sarcopenia, the decline in body cell mass (BCM) and especially in muscle mass with age, is an important age-related cause of frailty and loss of independence in the elderly. Because the decline in BCM with age parallels a decline in GH secretion from young adulthood to old age, loss of GH secretion has been considered an important contributory cause of sarcopenia in the elderly. To test this hypothesis in a group of healthy postmenopausal women (n = 15; mean +/- SD age, 66.