Objective: Weight loss is a primary manifestation of dementia. This review aimed to systematically synthesise the literature on total energy expenditure (TEE) in people with dementia. Methods: The protocol, registered with PROSPERO, was reported against PRISMA guidelines. Eligible studies investigated TEE in people with dementia. Six electronic databases and a supplementary Internet search identified relevant publications.Results were synthesised narratively. Results: The final library considered the TEE of 358 participants. Two studies used the gold standard method of doubly labelled water (DLW); other studies used TEE measures validated against DLW. TEE varied considerably, from 6095 ± 1353 kJ to 9765 ± 2066 kJ. The TEE of community-dwelling people with dementia (range 8430 ± 2250 kJ-9765 ± 2066 kJ) was higher than in institutionalised groups (range 6095 ± 1353 kJ-7619 ± 1827 kJ). Conclusion: New technologies will enable future research in this patient population to be less burdensome than those reliant on DLW measures. In planning future research, avoidance of selection bias and considering disease stage and movement are important considerations.

Weight loss, a hallmark feature of dementia, is associated with higher mortality in older people. However, there is a lack of consensus in the literature as to whether the weight loss commonly observed in older people with dementia results from reduced energy intake and/or increased energy expenditure. Understanding the cause of energy imbalance in older people with dementia would allow more targeted interventions to avoid detrimental health effects in this vulnerable group. In this paper, we review studies that have considered weight change, energy intake, and energy expenditure in older people with and without dementia. We critically assess the studies’ methodology and outline the various factors which may decrease and increase energy intake and expenditure respectively in older people with and without dementia. Current available literature does not support the view that there is a lower energy intake and/or a higher energy expenditure in older people with dementia when compared to those without dementia. The need for more high-quality studies is also highlighted in order to shed more light towards this issue which continues to elude researchers and clinicians alike.