I. A new apparatus is described with which it is possible to measure the volume (and hence density) of obese patients without requiring them to immerse totally in water. Replicate measurements of subjects with 6, 23 and 38 kg body fat had a standard deviation not greater than 0.3 kg fat.2. In nineteen obese women body fat was measured by density, total body water, and total body potassium at the beginning, and again at the end, of a period of 3-4 weeks on a reducing diet, during which they lost 5.43 (SD I. 83) kg in weight. The composition of weight loss was also estimated both by energy balance and nitrogen balance during the interval between the two measurements of body composition.3. The estimates of fat content of the nineteen women at the start of the balance period were 45.63(SD 1450) kg by density, 48.07 (SD 13.88) kg by K and 47.09 (SD 13.85) kg by water. The correlation coefficient between the density and K estimate was 0-949, and for the density and water estimate it was 4. It is concluded that measurement of density by the new method provides a convenient method for estimating body fatness, and change in fat content, which compares favourably with estimates based on total body water or total body K. However, these methods cannot be used to provide an accurate estimate of the composition of a small weight loss in an individual since deviations up to 4 kg fat occur between fat loss based on change in density and those based on the more reliable (but more tedious) energy balance method. 0,971.
I . Weight loss, resting metabolic rate and nitrogen loss were measured in forty obese inpatients on reducing diets.2. Five subjects ate 3.55 MJ/d for 6 weeks (Expt I). Twenty-one subjects ate 4.2 MJ/d for the first week, 2.0 MJ/d for the second week and 4 2 MJ/d for the third week (Expt 2). Fourteen subjects ate 3.4 MJ/d for the first week and then 0.87 MJ protein or carbohydrate for the second or third weeks, using a cross-over design for alternate patients (Expt 3).3. Patients in Expt I had highest weight loss and N loss in the first z weeks, but adapted to the energy restriction over the remaining weeks. On average subjects were in N balance at the end of the study. 4. In Expt z patients eating 2.0 MJ/d in week 2 showed increased weight loss compared with week I . N loss was not raised but it failed to decrease as it had in Expt I. Weight loss and N loss were reduced on return to 4.2 MJ/d for a third week. 5.In Expt 3 patients eating 0.87 MJ protein showed significantly more weight loss and less N loss than patients eating 087 MJ carbohydrate.6. Resting metabolic rate decreased with time on the low-energy diet, but the manipulations of energy or protein content did not significantly affect the pattern of decrease.7. Both weight loss and N loss were greater the lower the energy intake, and both decreased with time. Diets with a high protein:energy value give a favourable value for N:weight loss at each level of energy intake.If the energy intake of an obese patient is reduced below the level of energy expenditure the energy stores of the body must decrease, and this is usually reflected in a decrease in bodyweight. The obese person has too high a fat:lean tissue value, so it is desirable that the weight loss should be mainly at the expense of fat. Since fat loss is a slow process, such patients yearn for treatment which will produce rapid weight loss. This can be achieved by treatments which cause the loss of water or lean tissue which are attractive to the patient in the short term, but only make matters worse in the long run. Resting metabolic rate (RMR) is the factor which chiefly determines how quickly obese patients can lose weight (Garrow et al. 1978) and this in turn is most closely related to lean body mass (Halliday et al. 1979) so treatment which causes excessive loss of lean tissue is self-defeating in the end. Calloway & Spector (I 954) made a comprehensive review of the effect of restricted energy and protein intake on N balance, and concluded that active young men in negative energy balance would inevitably be in negative nitrogen balance whatever the protein intake.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.