The malnutrition wars: new recommendations for energy prediction equations for over 65-year-olds.

For decades health care professionals and the nutrition workforce have been using equations to predict energy requirements in older adults. New international research spearheaded by the Monash University Department of Nutrition, Dietetics and Food has found that these commonly used equations are often inaccurate in predicting energy needs. Their work has identified the equations that best predict energy needs in a bid to mitigate unwanted weight loss in our aging population.

We now live in a world where our parents retire, grow into old age, travel the world and possibly become grandparents - we’re living longer. The size of the “grey” army isn’t set to slow down either, with the United Nations forecasting that the number of over 60’s will double from 901 million to 1.4 billion between 2015 and 2030, exploding to 2.1 billion by 2050 [1]! But just because we’re living longer, doesn’t necessarily mean we’re healthier. One of the challenges we’re facing is how to plan for this change so that healthcare across the spectrum of policy development, prevention and treatment can be delivered to these large numbers of older adults. A growing challenge being faced by older adults is malnutrition.

The World Health Organisation recognises malnutrition (both under and over nutrition) as one of six contributing factors to the declining physical and mental capacity of older people [2], and for very good reason. It increases the risk of falls, osteoporosis and fractures, slow wound healing, morbidity, mortality and contributes to poor quality of life [3]. It’s even an accelerator to entry to residential aged care [4].

The number of older Australian’s experiencing malnutrition is heartbreaking. Approximately 8% of older Victorians receiving home nursing are malnourished, with a further 35% at risk of malnutrition [5]. Alarmingly, in residential care, we see the prevalence of malnutrition range from 22% up to a staggering  50% [4]. These statistics represent a failure of our current system in the prevention and management of malnutrition, with the recent Royal Commission into Aged Care uncovering harrowing tales of malnutrition, abuse and poor treatment of the older adults in our families and communities.

But why is it that in developed countries like Australia, with an abundance of fresh produce, access to safe and nutritious food, we seeing such staggering rates of malnutrition in this population group? This is a question that has plagued Monash University Department of Nutrition, Dietetics and Food researcher and Advanced Accredited Dietitian Associate Professor Judi Porter.

“One of the key issues that will underpin nutrition policy and practice into the future is the amount of energy from food needed by this group [older adults] to optimise their nutritional status” explained Judi. Currently, policy (eg. NHMRC Nutrient Reference Values), menus for hospitals/aged care residences, and individuals in clinical practice usually relies on the use of predictive equations.  These equations fit the populations on which they were developed, but of concern, few have used adults 65 years and over when the equations were established. For Judi, a key question emerged, how can we accurately predict the energy requirements of adults 65 years and over?  Judi explained that she has been “leading a large international team over the past few years to answer this question, and our results have been reported recently in the American Journal of Clinical Nutrition”.

“This collaboration was a multi-step process, where we developed a database of energy requirements (measured using gold standards - doubly-labelled water) of all research of free-living adults 65 years and over”.  Through this process, Judi identified that several data sets of gold standard data had been lost to research due to changes in personnel and missing records. To address this roadblock Judi and her team formed a collaboration with experts in the US to obtain data from the large Health ABC Study, and the Women’s Health Initiative. “Creating this team really expanded the database to over 1,000 participant data points” explained Judi. “This was important in being able to make even more meaningful conclusions, as many of the predictive equations have been formulated on what we would now consider being small participant sizes”.

Based on the findings, Judi and her team identified that when estimating the energy requirements of older adults that the Ikeda, Livingston and Mifflin equations most closely predict energy needs. Whereas the Schofield equation - one of the most widely used equations in practice - did not predict energy needs as well. It overestimates mean resting metabolic rate by 362kJ per day in adults 65 years and above - which becomes problematic when factoring in the physical activity level into the equation. She does urge caution, “while being the ‘best’ options available, these three equations still do not predict an individual's energy requirements as well as we would like - there is still large variability at an individual level per day”.

Judi also urges practitioners caution when estimating physical activity levels (PAL) - a key component in the prediction of energy requirements. “We also determined that PAL are far higher in free-living older adults than previously thought”.   Across adults 65 years and over, the mean PAL were 1.66 for females, and 1.69 for males.  These remained high into the free living adults 80 years and over, at 1.60 for females, and 1.65 for males. Therefore, physical activity should be considered within the context of the individual or group, and the appropriate level should be chosen.

More information

The systematic review identified a lack of Australian data. To address this data gap, Judi has received an Eastern Health Foundation grant to develop a study protocol and to pilot this with 20 older adults in Melbourne.  Data collection for this pilot study has been completed and the results are currently being analysed; we look forward to seeing the similarities and differences with participants in the international database.

Associate Professor Judi Porter is a researcher at the Monash University Department of Nutrition, Dietetics and Food. She specialises in systematic reviews, clinical nutrition and foodservice management.  Judi is an Accredited Practising Dietitian and a Fellow of the Dietitians Association of Australia. Click here to access Judi’s research profile. You can follow Judi on Twitter via @JudiPorter.

Stay up to date with the Monash University Department of Nutrition, Dietetics and Food on Twitter via @MonashNutrition.

This research was undertaken in collaboration with Professors Dale Schoeller (University of Wisconsin), Marian Neuhouser, Linda Snetselaar and Ross Prentice (Women's Health Initiative). All contributed large data sets to the analysis and the data interpretation process.

Publication information

Reference: Judi Porter, Kay Nguo, Jorja Collins, Nicole Kellow, Catherine E Huggins, Simone Gibson, Zoe Davidson, Dale Schoeller, Ross Prentice, Marian L Neuhouser, Linda Snetselaar, Helen Truby, Total energy expenditure measured using doubly labeled water compared with estimated energy requirements in older adults (≥65 y): analysis of primary data, The American Journal of Clinical Nutrition, , nqz200, https://doi.org/10.1093/ajcn/nqz200

Click here to access the paper published in the Americal Journal of Clinical Nutrition.

The Americal Journal of Clinical Nutrition is the highest ranked journal for original research within the field of Nutrition and Dietetics with an impact factor of 6.6.

Photo by Matteo Vistocco on Unsplash

References

1. United Nations, Department of Economic and Social Affairs, Population Division. World Population Ageing 2015 (ST/ESA/SER.A/390) [Internet]. New York: United Nations; 2015 [cited 12 September, 2019]. Available from: http://www.un.org/en/development/desa/population/publications/pdf/ageing/WPA2015_Report.pdf.
2. World Health Organization (WHO) Guidelines, 2017. Integrated Care for Older People - Guidelines on community-level interventions to manage declines in intrinsic capacity. Available from: https://www.who.int/ageing/publications/guidelines-icope/en/
3. Moreira NCF, Krausch-Hofmann S, Matthys C, Vereecken C, Vanhauwaert E, Declercq A, Bekkering GE & Duyck J. Risk factors for malnutrition in older adults: A systematic review of the literature based on longitudinal data. Advanced Nutrition. 2016; 7:507-22.
4. Dietitians Association of Australia. Royal Commission into Aged Care Quality and Safety. Canberra: Australia; 2019 [cited 12 September, 2019]. Available from: https://agedcare.royalcommission.gov.au/publications/Documents/background-paper-2.pdf
5. Rist G, Miles G, Karimi L. The presence of malnutrition in community-living older adults receiving home nursing services. Nutr Diet 2012; 69:46-50.