What to eat when off treatment and living with involuntary weight loss and cancer: a systematic search and narrative review

The aim of this study was to report a systematic search and narrative review of the evidence base that can inform dietary advice for patients off treatment living with cancer cachexia syndrome (CCS). Searches were conducted in MEDLINE, EMBASE, PsycINFO and CINAHL databases for publications about diet and cancer patients off treatment with symptoms of CCS. The following limits were applied: English language, from September 1998 to September 2008 and adults. In addition, a hand search included the reference lists of papers identified. Seven hundred and eighteen abstracts were assessed against inclusion/exclusion criteria and 88 were selected for full text independent examination by two researchers. Information from 48 papers was extracted, quality assessed, thematically analyzed and presented as a narrative synthesis. Two dominant perspectives emerged on what should be eaten by weight-losing cancer patients. The majority of authors advocated a nutrient-dense diet, facilitated by nutritional counselling. The alternative approach was to advise the patient to 'eat what they want'. There is little robust evidence to justify either approach as able to deliver on the range of physical and psychosocial objectives that they aim to achieve. A new model for the delivery of nutritional care may benefit cancer patients (off treatment) living with weight loss. The proposed model integrates the two identified perspectives to facilitate optimal food intake taking into account the patient's (1) disease symptoms and treatment side effects (2) emotional adaptation to illness and (3) social circumstances. Research is needed to establish which of these obstacles to eating can be changed for which patient groups to improve patient outcomes.