Enteral alimentation and repletion of body cell mass in malnourished patients with acquired immunodeficiency syndrome

The aim of this study was to determine the feasibility, tolerance, and efficacy of enteral feeding in malnourished AIDS patients. This was a prospective study of eight AIDS patients with severe eating disorders associated with systemic diseases. A defined diet was administered through an endoscopically placed gastrostomy tube. Body composition studies and selected serum and immunologic studies were done at baseline and monthly for 2 mo. Enteral feeding was associated with an increase of approximately 14% in total body potassium, an index of body cell mass (P less than 0.02), and an increase in body fat content (P less than 0.002). Serum albumin concentration (P less than 0.005) and iron-binding capacity also rose. Serum immunoglobulins did not change. The numbers of total lymphocytes (P less than 0.005) and CD8+ cells rose but CD4+ cells did not change. The tube and enteral feedings were well tolerated. These results demonstrate that enteral feeding may result in body-cell-mass repletion in malnourished AIDS patients.     

Response to total parenteral nutrition in the extremely malnourished patient

Changes in serum albumin levels and body weight are often used as indicators of the efficiency of a nutritional support regimen. Patients with moderate nutritional depletion demonstrate two distinct patterns of response during refeeding. The first is characterized by a decrease in the previously expanded extracellular fluid space with a rise in serum albumin and a loss of weight and the second by continued fluid retention with weight gain and no rise in serum albumin concentration. The second pattern has been observed in patients with ongoing stress such as infection. This study examines severely malnourished patients with no apparent inflammatory complications and demonstrates that this group responds to nutritional support in a pattern similar to that seen in the stressed patient. Eight patients with profound malnutrition were studied during the 1st week of nutritional support. Nitrogen balance was measured and the findings confirmed that all patients were anabolic. Sodium balances were used as an indicator of changes in the extracellular fluid compartment. Body weight and serum albumin were assessed daily. Body weight increased from 59 +/- 4 to 62 +/- 4% of normal (p less than 0.01) while serum albumin changed insignificantly (3.00 +/- 0.27 to 2.85 +/- 0.23 g/100 ml, NS) during the initial week of an adequate nutritional support regimen (nitrogen balance was +21.0 +/- 4.3 g, p less than 0.05). These changes were associated with a positive sodium balance (+215 +/- 20 mEq, p less than 0.05). These data confirm that some extremely malnourished patients do not experience a diuresis during the initial phase of nutritional support but rather may retain water and increase body weight.(ABSTRACT TRUNCATED AT 250 WORDS)     

Bioelectrical impedance analysis in HIV-infected patients treated with triple antiretroviral treatment.

BACKGROUND: Triple antiretroviral treatment including protease inhibitors (PIs) delays the clinical progression of HIV infection and may thus reduce the risk of malnutrition. However, fat redistribution (lipodystrophy) was recognized recently as a metabolic side effect of PIs. OBJECTIVE: The study aimed to assess the effect of triple antiretroviral treatment on body composition and on the prevalence of malnutrition. DESIGN: Two cross-sectional studies, 1 in 1996 (t96; n = 247) and 1 in 1997 (t97; n = 266), were conducted in HIV-infected outpatients. Among patients who participated in both studies, 111 patients started a new antiretroviral treatment including a PI between t96 and t97 and were studied longitudinally. Total body water (TBW), intracellular water (ICW), extracellular water (ECW), and fat mass were estimated by monofrequency bioelectrical impedance analysis (BIA). RESULTS: Prevalence of malnutrition was reduced by 30-50% from t96 to t97, depending on the definition used. In the longitudinal study, TBW and the ratio between ICW and ECW increased and fat mass decreased (P < 0.001). BIA indicated a greater increase in ICW in 23 (21%) patients with clinically apparent fat redistribution than in patients without this syndrome, but estimates of fat mass changes were not significantly different. CONCLUSIONS: Triple antiretroviral treatment may protect HIV-infected patients against the development of malnutrition. Whole-body BIA data suggest an increase in appendicular body cell mass associated with improved antiretroviral treatment. However, the method is unreliable in detecting fat redistribution, and current prediction equations will need to be recalibrated for HIV-infected patients receiving highly active antiretroviral treatment.     

Use of relative weight and Body Mass Index for the determination of adiposity

Relative weight and Body Mass Index (BMI) are commonly used as measures of body fatness in epidemiologic and clinical studies. In order to determine their accuracy, they were compared to body fat measured by underwater weighting and total body water determination in 29 males and 75 females who varied widely in body composition. Relative weights calculated from the Metropolitan Life Insurance Tables correlated so highly with BMI that these measures can be considered to be identical (R2 = 0.992 to 0.999). Linear regression analysis showed a significant correlation between BMI and percentage body fat in men (R2 = 0.68, %fat = 0.99 X BMI -1.32, p less than 0.001) and women (R2 = 0.74, %fat = 0.94 X BMI + 10.77, p less than 0.001). We conclude that relative weight and BMI are nearly identical, and that they are reasonable estimates of body fatness.     

Nutrition status in patients younger and older than 60 y at hospital admission: a controlled population study in 995 subjects

OBJECTIVE: Body weight and body mass index are easily obtainable indicators of nutrition status but do not provide information on changes in fat-free mass (FFM) and fat mass with age. In this prospective controlled study, we investigated whether body composition measurements were useful in identifying moderately or severely depleted patients, as judged by the Subjective Global Assessment at hospital admission. In addition, the subjects were grouped by age (< or =60 and >60 y) to determine whether there was an effect of aging on the prevalence of malnutrition.METHODS: Nine hundred ninety-five consecutive patients were evaluated for malnutrition by body mass index, serum albumin, Subjective Global Assessment, and 50-kHz bioelectrical impedance analysis and compared with 995 age- and height-matched healthy volunteers for FFM and fat mass. RESULTS: A body mass index less than 20 kg/m(2) was found in 17.3% of patients. Low albumin (< or =34.9 g/L) was found in 14.9% of all patients and 23.7% of those older than 60 y. In contrast, 23.1% and 38.3% of all patients were severely and moderately depleted, respectively, according to the Subjective Global Assessment. FFM was significantly lower in severely depleted men and women and moderately depleted women (P < or = 0.001), and fat mass was significantly higher (P < or = 0.05) in well-nourished patients than in volunteers. Patients older than 60 y had lower FFM and higher fat mass than did patients 60 y or younger or volunteers (P < or = 0.001). CONCLUSION: The prevalence of malnutrition was greater in patients older than 60 y than in those 60 y and younger. Patients classified as severely depleted according to the Subjective Global Assessment were depleted of FFM. Body composition measurement can help to identify patients with low FFM and high fat mass.     

应用生物电阻抗分析法检测营养不良病人的人体组成

目的 :应用生物电阻抗分析法 ,检测营养不良病人人体组成的改变。　方法 :中等程度以上营养不良住院病人 6 8例 ,其中男 4 0例 ,女 2 8例 ,年龄为 5 3± 16 (37～ 6 8)岁作为研究对象。 78名健康志愿者 (男 4 4 ,女 34)为对照者 ,年龄为 5 2± 11(38～ 6 2 )岁。人体组成测定应用HYDRAECF/ICF 4 2 0 0多频率生物电阻抗分析仪。　结果 :营养不良病人实际平均体重是理想体重的 6 8.8% ,其体质指数、肱三头肌皮皱厚度、臂肌围、白蛋白、转铁蛋白、前白蛋白及淋巴细胞总数均明显低于正常值 ,属中、重度营养不良范围。营养不良病人的体脂、瘦组织群、体细胞群及细胞内液含量均明显低于健康志愿者 (P <0 .0 5 )。细胞外液含量比例高于健康志愿者 (5 8.5 %vs 4 8.5 % ) (P <0 .0 5 )。　结论 :营养不良时人体体脂、瘦组织群和体细胞群存在不同程度的消耗 ,机体细胞内液丢失 ,而细胞外液增加。     

Successful management of chronic intestinal pseudo-obstruction with home parenteral nutrition

Chronic intestinal pseudo-obstruction is a disorder of gut motility resulting in severe abdominal pain, bloating, nausea, and vomiting after eating. The avoidance of food in order to minimize symptoms causes malnutrition. To date, no medical or surgical treatment has been shown to be of lasting benefit. We treated 10 patients disabled by chronic intestinal pseudo-obstruction using home parenteral nutrition. All were rendered minimally symptomatic as long as they refrained from significant oral intake. Nine of the 10 patients were malnourished prior to the institution of treatment. Home parenteral nutrition increased mean total body weight from 74.7 +/- 2.9 to 93.5 +/- 3.7% (p less than 0.001), mean lean body mass from 78.4 +/- 6.5 to a mean of 92.7 +/- 2.6 (p less than 0.02), and mean body fat from 57.1 +/- 8.8 to 83.8 +/- 8.2% of expected values (p less than 0.05). Mean total body potassium increased from 68.8 +/- 13.1 to 80.5 +/- 10.7 g (p less than 0.05). We conclude that in chronic intestinal pseudo-obstruction, home parenteral nutrition coupled with minimal oral intake effectively relieves symptoms and significantly improves the nutritional depletion.     

Selenium deficiency in the acquired immunodeficiency syndrome

Severe protein-calorie malnutrition is common in patients with AIDS (acquired immunodeficiency syndrome). These nutritional deficits are likely to further impair immune responses and other organ functions vital for recovery from serious infectious diseases. Since selenium deficiency is known to be associated with oral candidiasis and abnormal phagocytic function in animals and depressed helper T-cell numbers in man, we evaluated both selenium status and other nutritional parameters in 12 patients with AIDS compared to 27 healthy controls. Selenium was measured by a spectrofluorometric method. The mean (+/- SD) plasma selenium level in AIDS was 0.043 +/- 0.01 microgram/ml vs 0.095 +/- 0.016 microgram/ml in controls (p less than 0.001). Whole blood selenium and red blood cell selenium levels were also significantly reduced in AIDS (p less than 0.005). The mean weight loss in AIDS patients was 35.5 +/- 21.2 pounds. Serum albumin was significantly (p less than 0.01) lower in AIDS patients compared to controls. A good correlation between serum albumin and plasma selenium was noted (r = 0.77; p less than 0.001). We conclude that selenium deficiency is a common component of the malnutrition seen in AIDS patients. Therefore, aggressive nutritional support, including attention to selenium status, should be considered an integral part of the therapy of AIDS patients.     

Extracellular water: sodium bromide dilution estimates compared with other markers in patients with acquired immunodeficiency syndrome

Extracellular fluid and closely related extracellular water (ECW) provide information on nutritional status in health and disease. Although various methods exist for ECW determination, little is known about their comparability in patients with wasting diseases such as acquired immunodeficiency syndrome (AIDS). One practical method, the dilution of sodium bromide (NaBr), is used widely in clinical research, although its relationship to other ECW markers has not been well characterized. The present study sought to compare ECW estimates as determined by NaBr and three other methods in 11 male patients with AIDS (mean +/- SD; age, 44+/-12 years; body weight, 64.5+/-8.8 kg; and height, 172+/-4 cm). ECW volumes were determined from NaBr dilution, total body chlorine (TBCl) by delayed gamma-neutron activation analysis, total body water (TBW) by tritium dilution combined with total body potassium (TBK) by whole body 40K counting, and radioactive sulfate dilution (35SO4). All correlations between the NaBr method and other methods were statistically significant (NaBr vs TBCl [r = .91; p < .001]; vs TBW/TBK [r = .76; p < .01]; and vs 35SO4 [r = .89; p < .001]). As expected from previous studies, ECW (L) derived by NaBr provided a group mean (15.1+/-2.2 L) similar to the TBCl method (15.4+/-1.7 L; p = .32), a significantly smaller ECW than by the TBW/TBK method (18.6+/-3.4 L; p = .0004), and a significantly larger ECW than by 35SO4 method (13.3+/-3.0 L; p = .002). Estimating ECW by NaBr dilution was comparable with other research-based ECW methods and, thus, offers a practical alternative for evaluating ECW in patients with AIDS.     

Effect of home total parenteral nutrition on body composition in patients with acquired immunodeficiency syndrome

Malnutrition occurs commonly in patients with acquired immunodeficiency syndrome (AIDS). The efficacy of nutritional support is unknown. A prospective, longitudinal study was conducted to determine the effect of prolonged total parenteral nutrition on body composition in 12 AIDS patients. Five patients were malnourished because of problems with food intake or absorption, while seven had systemic infections, with or without a malabsorption syndrome. The AIDS patients gained body weight and body fat content in response to total parenteral nutrition, while mean body cell mass, estimated as total body potassium content, was unchanged. However, all five patients with altered intake or absorption had significant repletion of body cell mass which was significantly different from the patients with systemic infections. Calorie and nitrogen intake did not differ between the two groups. It is concluded that body mass repletion is possible in AIDS patients in whom malabsorption is the major pathogenetic factor in producing malnutrition and is less successful in patients with serious ongoing systemic diseases. Thus, the response to nutritional support is dependent on the particular clinical circumstances.     

Tissue nitrogen and potassium variation in trauma, starvation, and realimentation

Total body or exchangeable potassium is used as an important indicator of body cell mass in the study of body composition. Body composition studies have been used extensively in the study of nutrition but recent work has questioned the validity of using changes in total body potassium as a measure of protein or nitrogen variation. To investigate the relationship between tissue nitrogen and potassium during nutritional manipulation 382 tissue samples from 100 surgical patients were analyzed by Kjeldahl analysis for nitrogen content and flame photometric analysis for potassium content. Nitrogen was related to potassium in parenchymous or cellular tissues by the relationship N (mg/g) = 14.7 + 0.17 K (microEq/g). The tissue content of the two elements was highly correlated (r = 0.80, p less than or equal to 0.001). For skeletal muscle a similar relationship existed N (mg/g) = 16.6 + 0.15 K (microEq/g) (r = 0.76, p less than or equal to 0.001). These relationships held for all nutritional states and degrees of trauma and nutritional manipulation. In sequential parenchymous tissue samples obtained from 15 subjects delta N/delta K = 0.17 +/- 0.03 mg/microEq. Nonparenchymous or acellular tissue nitrogen and potassium were poorly correlated. The potassium content was very low in these tissues. Exchangeable potassium was a valid indicator of parenchymous tissue nitrogen and as such a legitimate measure of nutritional status.     

Ethics: responsible scientific conduct

Body composition and measures of obesity were evaluated in 59 subjects with myelomeningocele (MMC), aged 0.3-29 y, by anthropometry and measures of body cell mass (BCM) and intra- and extracellular water (ICW and ECW), derived from total body potassium and deuterium-isotope dilution; these results were compared with reference data. Body composition was normal in preambulatory children with MMC. Beyond ages 3-4 y there was significant depletion of BCM and total body water, with maldistribution of water (increased ECW and decreased ICW) and increased percentage body fat above that expected for age and sex. These findings were more pronounced in females and in those with high lesions, and were less pronounced in those who remained ambulatory. These changes may result in metabolic and nutritional maladaption during stress. The relation of BCM, total body water depletion and increased ECW to decreasing ambulatory activity suggests that early nutritional and mobility programs warrant further study.     

Nutrition and survival in patients with liver cirrhosis

Although the effect of malnutrition on survival has been demonstrated by a number of studies, it is not clear whether malnutrition represents an independent risk factor in patients with liver disease. We studied 212 hospitalized patients with liver cirrhosis who were followed clinically for 2 y or until death. Body fat and muscle mass were evaluated by triceps skinfold thickness (TSF) and midarm muscle circumference (MAMC), respectively. Multivariate analysis according to Cox's model assessed the predictive power of nutritional parameters on survival. Thirty-four percent of patients had severe malnutrition as determined by MAMC and/or TSF below the 5th percentile and 20% had moderate malnutrition (MAMC and/or TSF < 10th percentile). Twenty-six percent of patients were overnourished (MAMC and/or TSF > 75th percentile). Severely and moderately malnourished patients had lower survival rates than normal and overnourished patients. When analyzed with Cox's regression analysis, severe depletion of muscle mass and body fat were found to be independent predictors of survival. The inclusion of MAMC and TSF in the Child-Pugh score, the prognostic score used most with liver disease, improved its prognostic accuracy. The prognostic power of MAMC was higher than that of TSF. These data demonstrate that malnutrition is an independent predictor of survival in patients with liver cirrhosis. The inclusion of anthropometric measures in the assessment of these patients might provide better prognostic information.     

Total body water and total body potassium in anorexia nervosa

In the ill hospitalized patient with clinically relevant malnutrition, there is a measurable decrease in the ratio of the total body potassium to total body water (TBK/TBW) and a detectable increase in the ratio of total exchangeable sodium to total exchangeable potassium (Nae/Ke). To evaluate body composition analyses in anorexia nervosa patients with chronic uncomplicated semistarvation, TBK and TBW were measured by whole body K40 counting and deuterium oxide dilution in 10 females with stable anorexia nervosa and 10 age-matched female controls. The ratio of TBK/TBW was significantly (p less than 0.05) higher in anorexia nervosa patients than controls. The close inverse correlation found in published studies between TBK/TBW and Nae/Ke together with our results suggest that in anorexia nervosa, Nae/Ke may be low or normal. A decreased TBK/TBW is not a good indicator of malnutrition in the anorexia nervosa patient. The use of a decreased TBK/TBW ratio or an elevated Nae/Ke ratio as a definition of malnutrition may result in inappropriate nutritional management in the patient with severe nonstressed chronic semistarvation.     

Multicomponent methods: evaluation of new and traditional soft tissue mineral models by in vivo neutron activation analysis

BACKGROUND: Practical and accurate methods for quantifying the soft tissue mineral component of multicomponent fat-estimation models are needed. OBJECTIVES: The aims were to develop a new complete model for estimating soft tissue minerals based on measured total body water (TBW) and extracellular water (ECW) and a simplified new model based on TBW measurements only and to compare these estimates with those determined with 2 traditional models (ie, the Brozek and Selinger models) and with criterion estimates based on in vivo neutron activation (IVNA) analysis. DESIGN: The subjects were 156 healthy adults and 50 patients with AIDS. Total body potassium, sodium, chlorine, and calcium were measured by IVNA; TBW by (3)H(2)O or D(2)O dilution; ECW by bromide dilution; and bone mineral by dual-energy X-ray absorptiometry. RESULTS: The mean (+/- SD) mass of total-body soft tissue minerals in healthy adults was 467 +/- 62 g with the IVNA model, 492 +/- 62 g with the new model, and 487 +/- 59 g with the simplified new model. Compared with the IVNA model, the complete and simplified new models overestimated soft tissue minerals by 5.4% and 4.6% (both P < 0.001), respectively. In contrast, the Brozek and Selinger models overestimated overall mean soft tissue minerals by 35% and 99% (both P < 0.001), respectively. Overall results for soft tissue mineral prediction with the 2 new models were less satisfactory for the patients with AIDS, although the results were better than those with the traditional models. CONCLUSIONS: The physiologically formulated complete new model for estimating soft tissue minerals provides the opportunity to upgrade the accuracy of current multicomponent models for estimating total body fat.     

Nutritional status of adult inpatients in Bujumbura, Burundi (impact of HIV infection).

OBJECTIVE: To determine the prevalence and analyse the characteristics and causes of malnutrition among inpatients in an HIV highly endemic area. DESIGN: Prospective cross-sectional study. SETTING: Department of Internal Medicine, University Hospital, Bujumbura, Burundi. SUBJECTS: 226 adult inpatients. MAIN OUTCOMES MEASURES: Evaluation of nutritional status using anthropometry. Degree of malnutrition defined by the percentage of body weight loss (BWL), calculated by reference to the usual body weight. RESULTS: Among the 226 patients recruited (mean age: 34.4 +/- 11.9 y, M:F sex ratio: 1.72), 102 (45.1%) were HIV seropositive. 62 (60.8%) of these HIV seropositive were AIDS cases. The AIDS defining criterion was 'wasting syndrome' for 25 (40.3%) and opportunistic infection (OI) for 37 (59.7%) including 34 cases of tuberculosis (TB). The nutritional status of 119/226 patients (52.7%) was normal (BWL < or = 10%). Moderate malnutrition (10% < or = BWL < or = 20%) was observed in 47 (20.8%) and severe malnutrition (BWL > 20%) was observed in 60 (26.5%). HIV seroprevalence and, among HIV seropositive subjects, the percentage of AIDS cases increased according to decreasing level of nutrition (Chi2 for trends: P < 0.001 in both instances). The fat free mass mass of malnourished subjects was lower and the fat body mass was higher among HIV seropositive subjects than HIV seronegative subjects. Among HIV seropositive subjects, malnutrition was associated with TB (P < 0.001) and dysphagia (P < 0.05). Among HIV seronegative subjects, malnutrition was associated with decreased food availability (P < 0.003) and TB (P < 0.05). One week after admission, the mortality rate was higher among HIV seropositive subjects (10.8%) than seronegative subjects (2.4%, P=0.009). Other factors associated with death were decreased fat free mass (P < 0.01) and tricipital skinfold thickness (P < 0.04). CONCLUSIONS: The prevalence of malnutrition is high among the inpatients investigated. Main factors are HIV infection and TB. Strategies adapted to the African context should be developed to prevent, detect and treat malnutrition and associated factors, particularly among HIV seropositive subjects.     

Body composition of patients with spinal cord injury

Body composition of 10 control subjects and 37 spinal cord injured (SCI) patients was measured by dilution of 3H2O and Na2 35SO4. SCI patients were classified into four groups by ascending level of lesion, low and high paraplegics and low and high quadriplegics. The studies show diminishing total body water, intracellular water, lean body mass and body cell mass and increasing fat mass with higher spinal lesions. No differences in body weight or extracellular water were observed so that the ratio of extracellular water/total body water was increased as the level of injury increased.     

Nutritional status of HIV-infected patients during the early disease stages

Nutritional status was monitored in two groups of patients infected with human immunodeficiency virus (HIV) for up to 16 months. Twenty-six subjects were recruited from patients enrolled in acquired immunodeficiency syndrome treatment protocols in the early stages of the disease. Body weight, percent body fat, serum albumin, total protein concentration, hemoglobin, hematocrit, and total lymphocyte count were monitored monthly. Four-day food intake records were kept every 4 months. In the 19 patients followed for 16 months (Group 1), a significant (p less than .05) decrease was observed in body weight, percent body fat, body mass index (BMI), and total protein concentration. Seven subjects (Group 2), with more advanced disease than Group 1, demonstrated a significant (p less than .05) decrease in total lymphocyte count over a 5-month period. This latter group fell just below the normal range for hemoglobin and hematocrit concentrations during the study period. With the exception of a decrease in vitamin B-6, zinc, and total energy intake, food records closely matched the Recommended Dietary Allowance for the age group. Thus, we conclude that decreases in body weight, percent body fat, and BMI may be the earliest indication of decreased nutritional status in HIV-infected patients.     

Dietary intake in patients with acquired immunodeficiency syndrome (AIDS), patients with AIDS-related complex, and serologically positive human immunodeficiency virus patients: correlations with nutritional status

One of the major clinical manifestations of the acquired immunodeficiency syndrome (AIDS) and AIDS-related complex (ARC) is the development of cachexia. This most likely results from a multifactorial interplay of poor diet, malabsorption, and altered metabolism. To assess the potential role of nutrient intake in the development or persistence of malnutrition, a detailed analysis was performed of a 72-hr diet record in clinically stable patients with AIDS (N = 18), ARC (N = 12) and in human immunodeficiency virus (HIV) seropositive controls without significant manifestations of disease (N = 13). Total calorie intake was 39.1 +/- 13.2 kcal/kg/day in AIDS patients vs 34.6 +/- 7.8 kcal/kg/day in ARC patients or 31.9 +/- 17.7 kcal/kg/day in HIV seropositive cases (all p = NS). Likewise, mean protein intakes were similar among the groups and exceeded recommended daily dietary allowance (RDA) guidelines. The mean body weight changes from the inception of illness were -11 +/- 1% in AIDS, -6 +/- 7% in ARC, vs +3 +/- 2% in HIV-seropositive-only cases (p less than 0.05 vs AIDS and ARC). Dietary vitamin and mineral analysis revealed that 88% of AIDS, 88% of HIV seropositive, and 89% of ARC patients were ingesting less than 50% RDA for at least one nutrient. The mean number of deficiencies per patient was 1.8 +/- 1.3 in AIDS, 3.8 +/- 3.5 in ARC, and 2.9 +/- 2.5 in HIV-seropositive-only cases (p less than 0.05 AIDS vs ARC). There were no significant correlations between specific anthropometric measurements and dietary intakes of protein or fat.(ABSTRACT TRUNCATED AT 250 WORDS)     

The relationship between body fat mass and fat-free mass

It has been suggested that there is a curvilinear relationship between lean body or fat-free mass and body fat mass. In order to confirm this relationship, body composition was measured by determining body density and total body water using deuterium-labeled water in subjects varying widely in body fat mass. There were 29 males and 75 females with body mass index ranging from 20 to 66 kg/m2. The relationship between fat-free mass and fat mass appeared to be linear over the range of body fat from 10 to 90 kg: males R2 = 0.67 (p less than 0.0001) and females, R2 = 0.47 (p less than 0.0001). The amount of variance explained was not greater when the log of fat mass was used in place of fat mass alone. Multiple regression analysis demonstrated that the relationship between fat-free mass and fat mass remained significant (p less than 0.001) after adjusting for body height, age, and fat distribution. It is concluded that over the range of body fat extending from 10 to 90 kg there is a positive and linear relationship between fat-free body mass and fat mass.