Neurobehavioural and Cognitive Changes in Cancer Cachexia (CANCOG)

Inclusion Criteria: General inclusion criteria for all groups: * Written informed consent * Aged 18 years or over * Willing and able to comply with study procedures and visits Additional inclusion criteria for participants with cancer: * Histological or cytological diagnosis of cancer or confirmed non-intracranial malignancy on imaging. * Unintended documented weight loss of \>5% body weight in 6 months which is felt to be cancer related, OR patient reported weight loss and/or change in appetite Exclusion Criteria: General exclusion criteria for all groups: * Non-fluent English speaker * Active infection, as determined by the investigator based on clinical symptoms and / or fever and / or requirement for antibiotics * Women, who are pregnant, plan to become pregnant or are lactating. * MRI contraindication * A significant acute, chronic or psychiatric condition which in the judgement of the investigator would place the volunteer at undue risk or interfere with the study * Metabolically or clinically unstable on day of study visit * Artificial nutrition * Taking medications which, as determined by the investigator, may affect appetite or cognition, or otherwise affect completion of study tasks. * Weight or body circumference above upper threshold for MRI scanner (220kg) * Unresolved obstructive gastrointestinal (GI) lesion Additional exclusion criteria for participants with cancer: • Intracranial cancer or metastatic intracranial involvement of cancer Additional exclusion criteria for healthy volunteers: * Have, or be recovering from, any form of cancer * Unintentional weight loss of \>5% body weight or unexplained loss of appetite