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Biomedical subjects

J S Garrow

Publications and source records attributed to J S Garrow.

At least 109 records · Page 6Linked to original sources

A new method for measuring the body density of obese adults.

1. 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 1.83) 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 ninetten women at the start of the balance period were 45.63 (SD 14.50) 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 0.971. 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.

Adipose Tissue↗

Resting metabolic rate, weight, surface area and body composition in obese women.

Resting metabolic rate was measured in 22 women with varying degrees of obesity. Body composition was estimated from total body potassium and from total body water, and creatinine excretion in urine was measured over a period of three weeks while the patients were on a creatinine and creatine-free reducing diet. Resting metabolic rate was highly significantly correlated with body weight, surface area, creatinine excretion and lean body mass calculated either from potassium or water measurements (P less than 0.001). Correlation with adipose tissue was less strong, and when multiple regression of both fat and lean on metabolic rate was performed, the relationship was seen to depend mostly on the mass of lean rather than adipose tissue. In obese people the water content of fat-free tissue is greater than that in normal subjects, so it is not valid to assume that fat content can be calculated accurately from a measurement of total body water.

Adipose Tissue↗

Does adipose tissue cellularity or the age of onset of obesity influence the response to short-term inpatient treatment of obese women?

Thirty-three obese women were admitted as inpatients to a metabolic ward and had an average intake of 3.35 MJ (800 kcal) daily for three weeks. Fat biopsies were taken at three subcutaneous sites and average fat cell mass (CM) and apparent fat cell number (FCN) were calculated. There was no significant correlation between adipose tissue cellularity (CM or FCN) and total weight loss or resting metabolic rate, provided due allowances were made for the severity of obesity in each case. Neither was there any significant correlation between short-term weight loss and the age of onset of obesity. Resting metabolic rate, and not adipose tissue cellularity or age of onset of obesity, is a better indicator of short-term weight loss under controlled inpatient conditions.

Abdominal Muscles↗

Female fat distribution--a photographic and cellularity study.

A new method of classifying women according to their pattern of fat distribution is discribed. Standard linear-discriminant analysis of data from somatotype photography shows that the most important measurements are those of thigh and waist diameters and a simple ratio of these is proposed as a fat distribution (FD) score, ie one which distinguishes an android or central-type fat distribution from a gynoid or peripheral-type fat distribution: FD score = 26 log10 (formula: see text) The score is shown to correlate positively with age, actual weight and relative weight in 90 subjects, showing that older, fatter women are more likely to have a central-type of fat distribution. The score is also significantly positively correlated with the size of fat cells in the arm and waist measured in 46 subjects, showing that women with central-type fat distribution have larger fat cells in the upper parts of their bodies compared with women with peripheral-type fat distribution. Analysis of FD score before and after weight loss showed no significant correlation between the change in FD score and the degree of weight loss. This suggests that the pattern of female fat distribution as defined by the FD score is relatively constant.

Adipose Tissue↗

Factors determining weight loss in obese patients in a metabolic ward.

A metabolic unit is described in which it is possible to make controlled measurements of energy balance in patients with various types and degrees of obesity. Thirty-seven obese women were studied for three consecutive one-week periods on a diet which provided an average of 3.4MJ (800 kcal) daily, and some also undertook an exercise programme involving the expenditure of 850--1275 kJ (200--300 kcal) extra per day. The distribution of energy intake was varied from week to week, and within the day (nibbling and gorging), but neither these variations in dietary pattern nor the exercise programme significantly affected the total weight loss over the three-week study period. Very large variations were observed between individuals. Total weight loss over the three-week study period ranged from 1.6 to 9.8 kg. The best predictor of weight loss in a patient on a strictly controlled diet is the resting metabolic rate. The previous diet also affects weight loss: patients who had been keeping to a reducing diet before admission lost less weight, especially in the first week, than those who had not been dieting immediately before admission to hospital.

Body Height↗