This study compared the accuracy of heart rate monitoring, pedometry, and uniaxial and triaxial aecelerometry for estimating oxygen consumption during a range of activities in Hong Kong Chinese boys. Twenty-one boys, aged 8–10 years, walked and ran on a treadmill, played catch, played hopscotch, and sat and crayoned. Heart rate, uniaxial and triaxial accelerometry counts, pedometry counts, and scaled oxygen uptake (SVO2) were measured. All measures correlated significantly with VO2 scaled to body mass−0.75 (SVO2). The best predictor of SVO2 was triaxial accelerometry (R2 = 0.89). Correlations in this study were comparable with those in a previous study that used identical methods on 30 UK boys and girls. These results provide further confirmation that triaxial accelerometry provides the best assessment of energy expenditure and that pedometry offers potential for large population studies.

The aim of this study was to investigate the relationship between habitual physical activity and body fatness in Hong Kong Chinese children. Fifty children aged 8–11 yrs wore a uniaxial accelerometer for 7 days to determine physical activity levels. The sum of seven skinfolds was used to estimate body fatness. Activity counts summed over 1 day (299384 – 140427, mean – SD) were similar to activity counts recorded in previous studies. Activity correlated significantly negatively with sum of skinfolds in boys (r = –.50, N = 24, P < .05) but not girls. In conclusion this study supports a negative relationship between physical activity and body fatness in Hong Kong Chinese boys.

Comparisons of isonitrogenous supplements (1.2 g N) of essential amino acids and five keto acid analogues with four essential amino acids were made in seven patients with stable chronic renal failure (creatinine clearance, 4.6 to 16 ml/min) on moderately protein-restricted diets (4.60 to 7.8 g N per day). Full nitrogen balance data on the four patients who have already completed studies lasting 24 weeks are presented. No benefits of keto acid over amino acid supplements were observed. Two transient episodes of hypercalcemia occurred during keto acid treatment. There was no improvement of renal function with keto acids. Also, no carry-over effects were seen after keto acid treatment. It is concluded that any beneficial effects of keto acids in patients with chronic renal failure are only likely to occur in those taking a diet of less than 30 g protein daily.

This study aimed to determine the relationship between bone mineral content, habitual physical activity, and calcium intake in children. Fifty-seven children, aged 8–11 years, wore pedometers for seven days to assess activity. Calcium intake was estimated by a 4-day food diary. Bone mineral content (BMC) and areal density (BMD) were measured at the total proximal femur and femoral neck using dual energy X-ray absorptiometry. Regression analysis was used to assess contributions of physical activity and calcium intake to BMC, residualized for bone area and body mass. Physical activity explained 11.6% of the variance in residualized BMC at the proximal femur and 14.3% at the femoral neck (p < 0.05). Calcium intake added to the variance explained at the proximal femur only (9.8%, p < 0.05). This study provides evidence for an association between BMC and habitual physical activity.

6 patients in end-stage renal failure of varying aetiologies have been studied on low protein dietary regimens according to a P 6 formulation. All patients had part of their daily protein allowance substituted by an essential amino acid capsule also containing histidine and glutamic acid. All patients were maintained in nutritional balance as a result of the regimens prescribed. No toxic effects were noted and patient compliance was good. Our studies suggest the amino acid formulation given is safe and did not cause any fluctuations in patient plasma amino acid profiles. Our studies suggest an improved method of low protein dietary management for chronic renal failure patients together with a greater flexibility and wider range of prescribing possibilities. It is recommended that amino acid supplements according to the formula produced here constitute an improvement on currently prescribed Giovannetti regimens.