The nutritional care and management of patients includes provision of adequate nutrition support to ensure that they attain and maintain a desirable body weight, improve nutritional status and avoid negative outcomes associated with over- or underfeeding. The success of nutrition support relies on accurately estimating energy requirements so that adequate energy and nutrients can be provided to the patient. Energy requirements are most accurately determined by measurement of energy expenditure. Most methods for doing so however are expensive, time-consuming, require trained technicians to perform them and are therefore impractical in the clinical setting. As such, prediction equations, which are easy to use, inexpensive and universally available, are commonly used to estimate the energy requirements of hospitalised patients. The accuracy of these equations however is questionable. Recently, a new portable hand-held indirect calorimeter (MedGem(tm), HealtheTech, USA), which has been promoted for its ease of use and relatively short measurement time, has been validated in healthy subjects but is yet to be validated in patients with illnesses. Weight loss and malnutrition occur commonly in patients with cancer and are often thought to be associated with disturbances in energy metabolism caused by the tumour. Minimising weight loss is an important goal for the nutritional care of patients with cancer. The ability to accurately determine the energy requirements of these patients is therefore essential for the provision of optimal nutrition support. This research project proceeded in two phases. Phase 1 aimed to determine current methods used by dietitians for estimating adult patients' energy requirements using a descriptive study. Results of this study informed phase 2, which aimed to investigate differences in energy expenditure of cancer patients compared to healthy control subjects and to compare different methods for determining energy requirements of people with cancer in the clinical setting. To address phase 1 a national cross-sectional survey of dietitians working in acute care adult hospitals was undertaken to determine their usual dietetic practice with respect to estimating patients' energy requirements. Responses to the survey (n=307, 66.2%) indicated a large variation in dietitians' practice for estimating energy requirements particularly with respect to the application of methods involving injury factors. When applied to a case study, these inconsistencies resulted in an extremely wide range for the calculated energy requirement, suggesting that there is error inherent in the use of prediction methods, which may be associated with negative consequences associated with under- or overfeeding. The types of patients for whom dietitians estimate energy requirements appears to be heavily influenced by feeding method. Initial dietetic education was identified as the main influencing factor in the choice of method for estimation of energy requirements. Phase 2 was addressed using four studies based on the same study population - a case-control study, two clinical validation studies and a measurement methods study. Patients had histologically proven solid tumours, excluding tumours of the breast, prostate and brain, and were undergoing anti-cancer therapy (n=18). Healthy control subjects were group matched to cancer patients by gender, age, height and weight from a purposive sample (n=17). Resting energy expenditure (REE) was measured by respiratory gas exchange using a traditional indirect calorimeter (VMax 229) and the MedGem indirect calorimeter. A measurement methods side-study established that steady state defined as a three-minute period compared to a five-minute period measured REE within clinically acceptable limits. REE was also predicted from a range of prediction equations. Analyses of available data found that REE in cancer patients was not significantly different from healthy subjects, with only a 10% higher REE observed in this sample of cancer patients when adjusted for fat free mass. For both cancer patients and healthy subjects the portable MedGem indirect calorimeter and all prediction equations did not measure or estimate individual REE within clinically acceptable limits compared to the VMax 229 (limits of agreement of approximately -40% to 30% for both the MedGem and prediction equations). Collectively, the results of this research project have indicated that current practical methods for determining patients' energy requirements in a clinical setting do not accurately predict the resting energy expenditure of individual subjects, healthy or with cancer. Greater emphasis should therefore be placed on ensuring intake meets requirements. For this to occur, dietetic practice should be focused on directly monitoring both patients' actual energy intake and patient outcomes, such as weight, body composition and nutritional status, to determine whether energy requirements are being met. This research has led to multiple recommendations for dietetic practice, focusing on the standardisation of education practices. Recommendations for future research address methodological improvements.

Problématique : Les enjeux sociétaux du 21e siècle exigent des professionnelles de la santé de s’adapter à des situations de plus en plus complexes et ambiguës en développant de nouvelles compétences. Le Département de nutrition de l’Université de Montréal a entrepris une démarche de refonte complète de son programme de premier cycle pour adopter une approche par compétences en assurant l’alignement et l’atteinte des compétences requises pour la pratique actuelle et future de la profession diététique. Objectif : Ce projet vise à explorer en profondeur les perceptions des diététistes quant aux compétences nécessaires aux pratiques d’avenir de la profession diététique au Québec. Méthodologie : Étude qualitative avec 22 diététistes, dont 11 exerçant la profession au Québec dans des secteurs traditionnels et détenant une expérience de supervision de stagiaires et 11 pratiquant dans des secteurs de la pratique considérés comme émergents. Quatre groupes de discussion focalisée ont eu lieu à l’automne 2021, dont deux regroupant les diététistes pratiquant dans les secteurs traditionnels et deux autres incluant les diététistes ayant une pratique émergente. Résultats : Huit compétences transversales et une compétence disciplinaire ont été identifiées par les personnes participantes, comme étant nécessaires à la pratique diététique au Québec. Les tendances sociétales façonnant la pratique au Québec ont aussi été repérées. L’interprétation des données a permis d’explorer la perception des diététistes quant au niveau de préparation des futures diététistes à la pratique au Québec. Conclusion : La formation diététique devrait inclure le développement de ces compétences au sein du programme pour former des diététistes compétentes et prêtes à l’entrée à la pratique de la profession, en alignement avec les tendances sociétales et les besoins du marché du travail. Cette intégration des compétences permettrait de réduire l’écart entre la formation et la pratique dans le domaine de la diététique. / Background: The societal challenges of the 21st century require healthcare professionals to adapt to increasingly complex and ambiguous situations by developing new skills. The Université de Montréal’s nutrition department has undertaken a complete overhaul of its undergraduate program, adopting a competency-based approach to ensure the alignment and attainment of the competencies required for current and future practice in the dietetics profession. Objective: This project aims to explore in depth dietitians’ perceptions of the competencies required for the future practice of the dietetics profession in Quebec. Methodology: Qualitative study with 22 dietitians, including 11 practising the profession in Quebec in traditional sectors and who participated in trainee training, and 11 practising in sectors considered to be emerging from practice. Four focused discussion groups were held in the fall of 2021, two with dietitians practising in traditional sectors, and two with dietitians with an emerging practice. Results: Eight transversal competencies and one disciplinary competency were identified by the participants as essentials for dietetic practice. Societal trends shaping practice in Quebec were also identified. The interpretation of the data also enabled us to assess dietitians’ perceptions of the level of preparation of future dietitians for practice in Quebec. Conclusion: Dietetic education should include the development of these competencies within the curriculum to prepare future dietitians who are competent and ready to enter the practice of the profession in alignment with societal trends and the needs of the job market. This integration of skills would reduce the gap between training and dietetic practice.