|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)|
|Report of the working group on general principles of assessing energy requirements|
Working Group: M Buyckx,1 JL Dupont,2 JVGA Durnin,3 A Ferro-Luzzi,4 SB Roberts,5 B Schürch6 and PS Shetty7
1Food Policy and Nutrition Division, FAO, Via delle Terme di Caracalla, 00100 Rome, Italy; 2Agricultural Research Service, United States Department of Agriculture, Beltsville, MD 20705, USA; 3Department of Human Nutrition, Yorkhill Hospitals, Glasgow G3 8SJ, Scotland, UK; 4Istituto Nazionale della Nutrizione, Via Ardreatina 546, 00179 Rome, Italy; 5The Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, 711 Washington Street, Boston, MA 02111, USA;6International Dietary Energy Consultative Group (IDECG), c/o Nestlé Foundation. P.O. Box 581,1001 Lausanne, Switzerland; 7Centre for Human Nutrition, London School of Hygiene and Tropical Medicine, 2 Taviton Street, London WC1H OBT, UK
Descriptors: energy requirements, energy expenditure, methodology, research needs
1. Requirements for energy should continue to be defined in the terms used in the 1985 Expert Consultation, ie 'The energy requirement of an individual is the level of energy intake from food that will balance energy expenditure when the individual has a body size and composition, and level of physical activity, consistent with long-term good health; and that will allow for the maintenance of economically necessary and socially desirable physical activity'.
2. Estimates of energy requirements should be based on measures or estimates of energy expenditure, whether actual or desirable. This principle should be extended to all age groups, including children below 10 years of age. All currently available information on total energy expenditure should be taken into consideration for this purpose.
3. Intra-individual variation in BMR is small and negligible (with the possible exception of women in the reproductive age group), whereas inter-individual variation in BMR is relatively large and may reflect variations in body mass, body composition (in particular differences in the relative proportion of components of the fat-free mass), and physical activity related to lifestyle.
4. The BMR factorial approach should continue to be used as the basis for estimating the energy requirements of population groups worldwide.
5. The BMR factorial approach should also continue to be used to estimate energy requirements of light, moderate and heavy physical activity. The Group was of the opinion that 1.4 × BMR was the minimum acceptable maintenance level. More data are needed before considering any revision of the current factors for light, moderate and heavy physical activity for either sex.
6. More information is needed on the types, durations, patterns and energy cost of physical activities (as well as on integrated activities including rest pauses) for all ages and both sexes. This information is essential to assess the need for minimal levels of desirable activities and their long-term health implications.
The need to develop effective methods for delineating patterns of physical activity and for categorizing levels of activities in population groups was emphasized.
It was thought that there was a need for more investigations into concepts of 'desirable' body mass and 'desirable' levels of physical activity and their impact on long-term good health. Even though the relationship between lifestyle, body composition, energy expenditure and energy requirements needs to be explored further, the Group endorsed the desirability of short periods of activity to maintain physical fitness and promote cardiovascular health.
7. While being aware of some evidence of metabolic adaptation to under- and over-feeding, it was judged that no allowances needed to be made to account for this when estimating energy requirements of healthy populations.
8. Concern was expressed for methodological issues related to the validity of energy expenditure measurements. The group advocated the use of multiple approaches to the estimation of energy expenditure, with awareness of their advantages and limitations. It emphasized the need for quality control and the importance of representative population sampling in all efforts at obtaining more data.
Correspondence to: B. Schürch
1. More total energy expenditure measurements are needed in the age ranges from 6 to 12 months, from 1 to 7 or 8 years and over 60 years, to provide a more robust database.
2. More BMR measurements using strict criteria are needed in order to generate predictive equations based on anthropometric indices, particularly in children < 10 years of age and in the 60+ years age group.
3. Aware of the limitations of the Schofield BMR predictive equations, the Group endorses the IDECG's role in the re-analysis of BMR predictive equations from a wider database and using stricter criteria.
4. There is a need to investigate the causes of the relatively large inter-individual variations in BMR. Issues that need attention are the contribution of variations in body composition (in particular those related to the components of fat-free mass), as well as other anthropometric parameters (specifically stature) and their relation to lifestyle, ethnic variations and the range of ambient environmental temperatures.
5. More information is needed on PALs for different levels of activities in all age groups.
6. Minimal levels of physical activity and their impact on long-term health need to be assessed.
7. There is an urgent need to develop new and more precise methods for the rapid, qualitative appraisal of patterns and levels of physical activities of population groups worldwide.