Intra-individual variability and measurement noise in estimates of energy expenditure by whole body indirect calorimetry

Murgatroyd, P. R.; Davies, H. L.; Am, Prentice

doi:10.1079/bjn19870104

Cited by 63 publications

(45 citation statements)

References 4 publications

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“…11 Whereas the acute thermogenic effect increases EE above baseline the lower chronic dose of sibutramine did not raise EE but did have a desired effect of disinhibiting the normal reduction in EE seen with decreasing energy intake and weight loss. The within subject coef®cient of variation for 24-h EE is fully comparable with that of other studies 13,17,20 and the effect found in the present study is very similar to the results reported by Astrup et al, who found that the decrease in 24-h EE was 3 ± 5% less after eight weeks of treatment with ephedrineacaffeine compared with placebo. 21 We observed that sleeping EE was slightly higher in the sibutramine group than the placebo group after 8 weeks.…”

Section: Discussionsupporting

confidence: 82%

The effect of sibutramine on energy expenditure and appetite during chronic treatment without dietary restriction

Hansen¹,

Toubro²,

et al. 1999

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OBJECTIVE: To assess the contribution of a thermogenic effect to weight loss induced by eight weeks treatment with sibutramine (15mgad) vs placebo in obese subjects. DESIGN: Randomised, placebo controlled, double blind study. SUBJECTS: Thirty-two (7 male, 25 female) healthy obese body mass index (BMI) 33.9 AE 0.5 kgam 2 subjects completed the trial. MEASUREMENTS: Energy expenditure (EE) was measured by indirect calorimetry during a 32 h stay in a respiration chamber before and after 8 weeks treatment. Visual analogue scales were completed for assessment of appetite sensation. No dietary restriction was given. RESULTS: Sibutramine caused a signi®cant weight loss compared with placebo ( 7 2.4 kg vs 0.3 kg, P`0.001). Despite the larger weight loss after 8 weeks, 24-h EE did not decrease more in the sibutramine than in the placebo group ( 7 2.6% vs 7 2.5%, P ns). When the changes in 24-h EE were adjusted for changes in body weight, 24-h EE decreased signi®cantly less in the sibutramine group than in the placebo group (0.8% vs 3.8%, P`0.02). Sibutramine signi®cantly decreased both hunger and anticipated food consumption, and increased satiety scores. CONCLUSIONS: The weight reducing effect of sibutramine in humans is caused by a dual mechanism: reduction of energy intake by increasing satiety and decreasing hunger and prevention of the decline in EE that follows weight loss.

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Section: Discussionsupporting

confidence: 82%

The effect of sibutramine on energy expenditure and appetite during chronic treatment without dietary restriction

Hansen¹,

Toubro²,

et al. 1999

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“…Similar results were observed by others (Table 4; Murgatroyd et al 1987;Fredrix et al 1990;Rieper et al 1993;Figueroa-Colon et al 1996;Ventham & Reilly, 1999). Discrepancies could be due to differences in protocol, methodology and study population.…”

Section: Discussionsupporting

confidence: 77%

Intra-individual variation of basal metabolic rate and the influence of daily habitual physical activity before testing

2003

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The present study determined the intra-individual variation of BMR measurements, using a standard out-patient protocol, with the subjects transporting themselves to the laboratory for the BMR measurements after spending the night at home. The effect of a non-fasting state and variation in daily habitual physical activity the day before testing was evaluated. Eight male and eleven female subjects participated in three BMR measurements with 2-week intervals. Physical activity was estimated with a tri-axial accelerometer for movement registration, during the 3 d before each BMR measurement. There were no significant differences in estimated BMR (ANOVA repeated measures, P¼0·88) and in physical activity (ANOVA repeated measures, P¼0·21). Mean within-subject CV in BMR was found to be 3·3 (SD 2·1) %, ranging from 0·4 to 7·2 %. Differences between BMR measurements could not be explained by differences in physical activity the day before; however the mean within-subject CV in BMR changed from 5·7 to 5·2 % after correcting for within-machine variability and from 5·2 to 3·3 % after excluding five measurements because of non-compliance to the protocol including fasting. In conclusion, BMR values measured with a standard out-patient protocol are sufficiently reproducible for most practical purposes despite the within-subject variability in physical activity the day before the measurement. For this purpose, however, non-fasting subjects must be excluded and a regular function check of the ventilated-hood system is recommendable. Reproducibility: Calorimetry: Body composition: AccelerometerBMR is the main component of average daily metabolic rate. It is defined as the daily rate of energy metabolism an individual needs to maintain and preserve the integrity of vital functions. A measurement of BMR must meet certain conditions. The subject must be awake and the measurement must be performed in a thermoneutral environment to avoid heat production or heat loss for maintenance of body temperature. Furthermore the subject must be in a fasted state (absence of diet-induced thermogenesis) and in rest (absence of activity-induced energy expenditure).Diet-induced thermogenesis is an increase in energy expenditure (EE) above BMR after eating. A 10 -12 h fast before BMR measurements is the accepted procedure followed by investigators to eliminate the thermic effect of food on basal EE. However, the time interval required to eliminate any residual effect of physical activity on BMR has not yet been described in a similar way. Some studies have observed that moderate-intensity physical activity elevates metabolic rate for only a few minutes to a few hours (Bahr et al.

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“…1995), acute weight-loss (Jebb et al 1991) or pregnancy . Measurements of energy expenditure can be made with an accuracy of f 1 % over periods as short as 1 h, but potentially lasting for many days, to the limit of subject tolerance (Murgatroyd et al 1987).…”

Section: Metabolismmentioning

confidence: 99%

Obesity: from molecules to man

Jebb

1999

Proc. Nutr. Soc.

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Obesity is now a major public health problem in both developed and developing countries. In the UK over 16 % men and 17.5 % women are obese, an increase of more than 100 % since 1980. However, interventions to prevent and treat obesity are hampered by an inadequate understanding of the aetiology of this condition. The present paper considers the current state of knowledge regarding the causes of obesity, including some of the genetic, metabolic, behavioural and environmental factors which influence energy balance. The present paper comprises The Nutrition Society Medal Lecture and focuses in particular on the research carried out at the MRC Dunn Nutrition Centre in Cambridge. It argues that despite decades of intensive research there is relatively little evidence of genetic or metabolic defects to explain the majority of cases of human obesity. Instead we must look to behavioural and/or environmental factors which may be underpinning the current epidemic of obesity.

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Intra-individual variability and measurement noise in estimates of energy expenditure by whole body indirect calorimetry

Cited by 63 publications

References 4 publications

The effect of sibutramine on energy expenditure and appetite during chronic treatment without dietary restriction

The effect of sibutramine on energy expenditure and appetite during chronic treatment without dietary restriction

Intra-individual variation of basal metabolic rate and the influence of daily habitual physical activity before testing

Obesity: from molecules to man

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