Definition and Prevalence
Loss of weight (cachexia) and appetite (anorexia) are significant concerns for many palliative care patients, and independently predict a poorer prognosis. [1-3] The palliative conditions in which cachexia and anorexia occur most frequently are progressive malignancy, HIV/AIDS, end-stage cardiac failure, end-stage respiratory failure, chronic renal failure, chronic liver disease, and advanced dementia. A focus on weight gain on its own may not result in meaningful clinical changes for palliative care patients. 
Potentially reversible contributors to appetite problems should be sought and treated as appropriate. These may include:
- Mouth problems - mucositis, oral thrush
- Family, social and cultural expectations related to food, diet, and body weight
- Inappropriate presentation of food
- De-conditioning / reduced level of activity
- Dysgeusia - changed sense of taste and smell
- Medication effects.
Assessment and Treatment
The relationship between catabolic state, hyper-metabolism, anorexia and nutritional intake, is extremely variable, complex and unpredictable. Appetite is a subjective symptom. Simple validated assessment tools are available, such as the Patient Generated Subjective Global Assessment. [15,16] However, expert consensus does not recommend any one tool over others.  With better understanding of cachexia anorexia syndrome, future treatments are likely to be multidimensional and initiated earlier. They may include appetite stimulants, tailored nutritional support and exercise,  and treatments to reverse the inflammatory drive associated with the syndrome. 
Assessment and treatment issues related to Cachexia Anorexia Syndrome, Appetite Stimulants and Nutritional Support are covered in more detail in the respective sub-section pages.
See individual subsections for practice implications in Cachexia Anorexia Syndrome, Appetite Stimulants and Nutritional Support.
- The European Association for Palliative Care (EAPC) is refining definitions of cachexia for palliative care, reviewing the significance of secondary nutritional impact syndromes, and studying the psychosocial outcomes of cachexia and anorexia, and developing a decision tool. 
- Some screening tools for appetite require external validation, and specific Quality of Life assessment tools are needed. 
- Study of the differences between specific cachexia syndromes - cancer, chronic renal failure and cardiac failure - is evolving. 
- Many studies with weight gain as an outcome do not identify how weight is gained - whether as muscle, fat, or oedema. Skeletal muscle mass, rather than total weight, is most closely associated with functional status. Other relevant outcomes such as quality of life, performance state, exercise and activity levels are now being studied in addition to changes in weight. 
- Significant muscle wasting (sarcopenia) may occur in patients with maintained body weight due to fat; the possibility of assessing this with CT scanning is being studied in order to identify those patients with early stages of cachexia who might benefit from earlier intervention. 
- 'Early satiety' is when a person wants to eat but can only take small amounts due to a sense of fullness. It is common in cancer patients and may be separate from other appetite problems, or it may co-exist with anorexia or nausea. Autonomic neuropathy may be a contributing factor. Early satiety is not well understood, but has been identified as an area for further research. 
- Dysgeusia (abnormalities of the sense of taste) have been found to be common during cancer treatment (56 - 76% estimated prevalence). It is often associated with other oral symptoms, and with a worse quality of life. Treatments that have been studied include prophylaxis with zinc and amifostine, which have been shown to be of small benefit. Dietary and educational counselling may be of some assistance. 
- The benefits of NSAIDs may be enhanced when used in combination with other appetite stimulators, although evidence for particular combinations remains low. [6,11]
- Inflammatory markers, including C-reactive protein and others, are being studied for potential clinical use as screening and monitoring tools in the cachexia anorexia syndrome, and as a possible intervention target. [23,24] Genetic polymorphisms are being investigated in the search for susceptibility biomarkers.