Mei-Uih Yang

Clinical correlates of short- and long-term weight loss

This study was designed to identify psychological, behavioral, and physiological correlates of short- and long-term weight loss. Measures of psychological functioning, body composition, fat cell size and number, and attendance were evaluated in 76 obese women for their relationship to weight loss at the end of treatment and at a 1-y follow-up evaluation. Losing more weight during the first month of treatment and attending a higher percentage of treatment sessions were strongly associated with greater weight loss at the end of treatment and at 1-y follow-up. In addition, patients with the highest initial weights lost the most weight both at the end of treatment and at 1-y follow-up. Easily obtained measures are as successful in predicting weight loss as are more expensive and complicated measures.

A new method for estimation of body composition in the live rat.

Abstract Measurement of total body electrical conductivity (TOBEC) has been used to estimate lean and fat content of meat based on the principle that electrical conductivity of lean tissue is far greater than that of fat. This approach was used to estimate body composition of live rats. An instrument designed for commercial analysis of ground meat (DjMe 100) was used to measure TOBEC in 30 male Sprague-Dawley rats (197-433 g). Individual TOBEC values were obtained in 20 seconds and repeated twice for each rat. The animals were then killed with ether, hair was shaved, lungs collapsed and body density measured hydrostatically. Carcasses were homogenized and analyzed for fat, nitrogen, and water. A high correlation was found between TOBEC and lean body mass by densitometry (r = .97) and between TOBEC and fat-free mass derived from direct carcass analysis (r = .97). Rats weighing up to 450 g could be accommodated in this particular instrument. Measurement of TOBEC should prove useful in estimating body composition and monitoring its changes in live rats and other small laboratory animals.

Resting energy expenditure in the obese: A cross-validation and comparison of prediction equations

OBJECTIVE To examine the accuracy and precision of 12 equations or tables for predicting resting metabolic rate (RMR) in obese persons. DESIGN Observational (correlational) study. SETTING Obesity Research Center, St Lukes/Roosevelt Hospital, New York, NY. SUBJECTS/SAMPLES One hundred twenty-six (73 women, 53 men) healthy, obese subjects recruited through the Obesity Research Centers Weight Control Unit. MEASURES RMR by indirect calorimetry. Weight and height were measured to the nearest 0.1 kg and to the nearest 1 cm. STATISTICAL ANALYSES PERFORMED Bivariate regression of predicted RMR on measured RMR; paired t tests for the difference between means of predicted RMR and measured RMR. RESULTS Of the 12 prediction equations, 6 had intercepts or slopes that were significantly different from 0 and 1, respectively. With two exceptions, the equations accounted for between 56% and 63% of the variance in measured RMR. The Robertson and Reid (1952) equation and the Fleisch (1951) equation performed best with our obese sample. APPLICATIONS/CONCLUSIONS The Robertson and Reid (1952) and the Fleisch (1951) equations are recommended for clinical use with obese patients.