17. CGA in Primary Care Settings: Weight loss and nutrition issues
Recognition of nutritional problems in older people is important as these are associated with poor prognosis but are potentially treatable. Any assessment of frailty should include some key questions about diet, appetite and weight, as these can indicate specific problems related to nutrition as well as being markers of other underlying medical conditions.
Nutritional status can be easily assessed using some basic tools such as the weight (or change in weight), BMI or MUST score (see below). These are non-specific but reasonably sensitive. The mini nutritional assessment (MNA) is useful in care homes as it includes hydration and allows for a care plan to be created.
Note that some patients will have a raised BMI due to excess body fat – this neither rules out frailty nor poor nutritional status – protein/energy deficiency and sarcopenia are common in older people including those with raised BMI (in fact body fat can make significant loss of muscle bulk difficult to spot). Unintentional weight loss is also an important marker of problems with nutrition or undiagnosed systemic illness such as malignancy or heart failure.
Frequently used risk factors for malnutrition are:
- Involuntary weight loss (more than 5% over the last month or more than 10% over the last six months).
- BMI less than 20 for elderly (≥ 65y).
- Decreased appetite or reduced food intake.
Other related issues include:
- Assessment of oral health (including dentures).
- Change in taste – older people can respond to a change in taste ‘everything tastes salty/sweet’ by not eating. Some drugs especially night sedation (the Z drugs) can alter taste sensation.
- Swallowing problems – asking about choking and things getting ‘stuck’ are often more productive than ‘difficulty in swallowing’ (Always refer swallowing issues for further investigation).
- Thyroid function.
- Alcohol intake.
- Bowel habit, as constipation can lead to reduced appetite.
- Older people are more likely to have B12 or folate deficiency due to diet or malabsorption which may be difficult to detect clinically.
- Also of value are assessment of mood (loss of appetite as a marker of depression) and cognition / function (inability to prepare or obtain adequate diet).
- Loss of appetite can also be a feature of dementia but generally only in the late stages – unless dementia is severe a change in appetite is more likely a marker of an acute illness, behavioural/psychological symptoms of dementia or undiagnosed systemic problem (eg constipation or malignancy).
Referral to the local dietetics service can be a cost-effective way of managing poor nutrition once secondary causes have been excluded. Oral protein and energy supplementation does result in weight gain and may also slightly improve survival in undernourished older people. Medications to stimulate appetite are unlikely to be effective. Decisions about supplemental feeding in patients unable to take this orally (ie by enteral tube feeding) are complex. The effects of increased nutrition may be negligible (and possibly harmful) in advanced frailty and dementia.
More about nutrition in general: Alibhai SMH, Greenwood C, Payette H. An approach to the management of unintentional weight loss in elderly people (Canadian Medical Association Journal. 2005;172(6):773-780. doi:10.1503/cmaj.1031527) NCBI.
To access the core tools:
BMI online calculator (weight(kg)/height2(m2)):
Mini Nutritional Assessment MNA.