|Energy and Protein requirements, Proceedings of an IDECG workshop, November 1994, London, UK, Supplement of the European Journal of Clinical Nutrition (International Dietary Energy Consultative Group - IDECG, 1994, 198 pages)|
|Energy requirements: general principles|
Suggestions have been made, at different places in the text of this paper, for further analyses or studies on various aspects of energy requirements. The different items are as follows:
BMR: A critical re-assessment of all the data is highly desirable. Particular attention needs to be given to the extent of intra- and inter-individual variability.
Physical activities: There is a need for further analysis and for more investigation into the energy cost of different activities. The confusing effect of uncertainty with regard to whether or not rest-pauses have been taken into account in the estimate of the energy cost of the different activities is discussed.
Doubly-labelled water: Its role is discussed briefly and a specific proposal is made in relation to its potential use in the investigation of the 'maintenance' factor, specifically applied to BMR and the activity factor in physically inactive populations.
Maintenance factors: The validity of some of these to real life situations are discussed with specific examples of practical implications of the factors 1.4 (for 'maintenance') and 1.2 (for 'survival').
Body mass and composition: It is doubtful if, within a fairly wide range of 'fatness' (but excluding the grossly obese), there is any real benefit in field situations from taking body composition into account, bearing in mind the extent of the variability of both BMR and total daily energy expenditure. In this context, because total body mass clearly has a considerable influence on energy expenditure, further studies of the effect of actual or desirable body mass are needed.
Population sample size: Because of the considerable variability in many aspects of energy metabolism, it is critical to have a sample size which has an acceptable statistical power and is reasonably representative of the particular variables being analysed. It is not scientifically admissible to make other than highly qualified deductions from data obtained on only small sample sizes. It is particularly depressing to read statements with sweeping generalizations about energy expenditure, which contradict data obtained on very large numbers of individuals by many experienced investigators, when the statements are based on findings on nine individuals (Haggarty et al, 1994).