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Older muscles have specific nutrition needs

As the body ages, it becomes much less efficient at restoring tissue; maintaining body weight whilst exercising requires a diet that compensates.

The words ‘first, do no harm’ do not appear as such in the Hippocratic Oath, as many people believe, but they are quoted often anyway. When it comes to concerns about obesity or being overweight in older people, these words certainly need to underpin care.

Carrying excess weight may cause difficulties with mobility for older people and can contribute to manual handling problems for staff in aged-care facilities. However, instigating a diet plan designed to reduce body weight in an elderly person can do more harm than good. In fact, those who are at the higher end of the weight tables in later life fare better on average than those who are at the lower end.

The difference in risk comes down to muscle mass. Age-related changes in physiology cause a loss of muscle mass in older people. This loss of muscle tissue is accelerated by weight loss and this is where damage is done.

Muscle provides mobility, however it is also the body’s reserve of protein for a wide range of vital processes – immune function, organ maintenance and wound repair, to name a few. It is typical for protein to be moved in and out of muscle throughout life in response to supply and demand; and in the young, any removed is efficiently replaced. Unfortunately, this is not the case in later life, as replacement is incomplete from middle age, leading to a gradual net loss of body muscle mass.

As decades progress, the age-related decline in mass becomes compounded by acute and chronic illnesses, periods of immobilisation, reduced activity levels and even the effect of some medications. Weight loss at later age just accelerates muscle wastage.

Even a seemingly insignificant loss of muscle mass (maybe 5kg body weight depending on the individual) can start to affect vital functions, resulting in a reduced immune response, slower wound repair and a hampering of body organ maintenance. Cognition may be affected as well as mobility, leading to the more obvious physical consequences, such as falls. These effects rapidly progress with further muscle mass losses.

When people in their later years reduce kilojoule intake, either intentionally in order to reduce body weight or unintentionally, muscle protein is disproportionately used to supply energy to the body and brain. This is in contrast to the situation in younger people, where body fat makes a far higher contribution and thus preserves muscle. So, in older people, rather than eliciting a loss of fat tissue, weight loss generally means a loss of muscle tissue and can quickly have a negative impact on the body.

Exercise is the key to avoiding the worst damage from weight loss. Muscles can be preserved and strengthened by doing the right exercise, even at advanced age. The type of exercise required is consistent, regular and quite intense resistance activity. Those who are able to do the necessary exercise should combine a professionally designed program (under the guidance of an exercise physiologist and/or a physiotherapist) with the assistance of an accredited practising dietitian (APD) who will design an eating plan with enough protein for muscles to recover after the workout.

Unfortunately, many older people will struggle to complete an exercise regimen like this. However, even if an older person is considered obese or overweight, a diet plan aimed at weight reduction is still not recommended, for reasons mentioned above.

There is no substitute for individual assessment by an APD and the wishes of elderly residents themselves must also be considered. One possible strategy might be to minimise the weight gain that occurs for some people when they move into assisted care and have them consume additional kilojoules by having all meals and snacks supplied. Screening tools, used to alert facilities to malnutrition, also need to highlight increases in residents’ weight so this can be managed early.

The importance of ensuring all people living in assisted care (whether in the community or in an aged-care facility) have access to exercise or physical activities that match their ability cannot be overstated. This is important for the sake of maintaining muscle, reducing falls risk, assisting food intake, keeping bowels active and maintaining bodyweight. This exercise must be combined with the provision of foods that support the unique nutritional needs of ageing bodies.

Neither will do harm, both will do some good.

Ngaire Hobbins is an accredited practising dietitian, a clinical practitioner, a clinical lecturer in dementia studies at the University of Tasmania, an aged-care consultant, a seniors’ advocate, and author of the book Eat To Cheat Ageing.

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