It is important to consume enough dietary protein each day to meet our essential protein requirements.
As we age we need to increase our daily protein intake
What is protein?
Protein is a macronutrient required by our bodies to function properly. 20 amino acids make up the building blocks of all proteins our body needs. They link together in different sequences to form a variety of proteins such as muscle, bone, collagen and compounds such as enzymes and hormones. There are 9 essential amino acids – meaning we must get these from our diet, and 11 non-essential amino acids – meaning our body can synthesise these on its own.
It is important to consume enough dietary protein each day to meet our essential protein requirements. Dietary protein comes from both animal and plant-based sources including meat, poultry, fish, eggs, dairy protein, nuts, seeds and legumes likes beans and lentils.
Why is it important to include protein in our diet?
Dietary proteins are vital for life. How much protein an individual may need depends on factors including their age, gender, health status and activity level. Protein does not just make up our muscle tissue, but any time our body is growing or repairing itself, protein is required.
Some key functions of protein in our body include:
- Forming enzymes that assist chemical reaction taking place within cells such as digestion and metabolism
- Forming cellular transporters that move nutrients into and out of cells
- Supporting the regulation and expression of DNA and RNA
- Creating neurotransmitters (chemical messengers within the body)
- Making and functioning as hormones
- Building lean muscle for improved strength and function
- Improving exercise performance
- Assist in weight management by affecting hunger levels – reducing the hunger hormone and increasing our satiety hormone.
Why it is important to have enough protein as we age and why we need to increase our daily protein intake?
The nutrient reference values (NRVs) for Australia and New Zealand recommended dietary intake (RDI) for protein is 0.84g/kg/day for men aged 19-70yrs of age and 0.75g/kg/day for a female aged 19-70yrs (1). This means any male aged 19-70yrs weighing 80kg requires 67g protein per day – about the amount of protein in 200g of chicken breast. A 60kg female of the same age would require 45g protein per day.
Several studies have shown that as people age, they consume less protein (3, 4, 5, 6) and this is closely linked with reduced muscle strength and function. Sarcopenia is the natural decline in skeletal muscle mass and strength seen with ageing and is a major contributor to increased mortality, morbidity and reduced quality of life in older people (7).
Healthy older people regardless of gender should consume at least 1.0-1.2g protein/kg/day to help limit the effects of sarcopenia and sustain muscle function and strength (3, 8). Consider spreading the protein meals thorough out the day or having your high protein meal at lunchtime (3).
References
1. Nutrient Reference Values for Australia and New Zealand. Australian Government, Department of Health and Ageing, National Health and Medical Research Council 2005 ISBN 1864962372https://www.nrv.gov.au/nutrients/protein
2. Australian Health Survey 4364.0.55.008 – Australian Health Survey: Usual Nutrient Intakes, 2011-12
https://www.abs.gov.au/ausstats/[email protected]/Lookup/by%20Subject/4364.0.55.008~2011-12~Main%20Features~Macronutrients~200
3. Bauer J et al. (2013). Evidence-Based Recommendations for Optimal Dietary Protein Intake in Older People: A Position Paper From the PROT-AGE Study Group. J Am Med Dir Assoc, 14(8), pp. 542-559
4. Rousset S, et al. (2003). Daily protein intakes and eating patterns in young and elderly French. Br J Nutr, 90, pp. 1107-1115
5. Fulgoni VL 3rd. (2008). Current protein intake in America: Analysis of the National Health and Nutrition Examination Survey, 2003-2004. Am J Clin Nutr, 87, pp. 1554S-1557S
6. Paddon-Jones D et al. (2008). Role of dietary protein in the sarcopenia of aging. Am J Clin Nutr, 87(suppl), pp. 1562S– 1566S
7. Nowson C, O’Connell, S, (2015). Protein requirements and recommendations for older people: a review” Nutrient, 14:7(8), pp. 6874-99.
8. Deutz et al, (2014). Protein intake and exercise for optimal muscle function with aging: recommendations from the ESPEN Expert Group. Clinical Nutrition, 33(6), pp. 929-36.
