Protein intake requirements increase with age (1.0–1.2 g/kg/day) due to anabolic resistance (blunted muscle protein synthesis response) and increased metabolism resulting from inflammatory conditions.
However, older adults can often struggle to consume adequate quantities of protein and this prevalence is relatively widespread given that 65–67% of community based older adults are below the suggested 1.2 g/kg/day threshold.
The authors of a recent study, which included a UK market review and consumer questionnaires, argue that more emphasis needs to be placed upon designing products to meet older adults’ requirements.
Previous studies have typically focused on understanding age-related differences or clinical outcomes rather than focusing on the product design perspective.
The current paper therefore aimed to: explore types of food matrices commonly fortified with protein with an initial literature and market review; determine consumers’ perceived ideal portion sizes for drinks and cakes; understand attitudes, consumption habits and preferences towards protein-fortified products; and provide practical solutions for future protein fortification of products.
The authors conclude: "Protein-fortified products are considered a well-tolerated and cost-effective approach, as well as falling within the food first remit. Therefore, it is important that next steps include research utilising ecological validity to understand better older adults’ preferences and behaviour in practice (e.g., in community and clinical settings) to determine whether these products can be incorporated easily into everyday lives.
"It is fundamental that the target audience (i.e., older adults) is involved in the design process to tailor such products to encourage interest and maximise trust."
The authors note their data reveals that products are typically more centred around animal derived protein sources than plant derived protein sources.
"However, with the increased demand to utilise plant derived protein sources; accordingly, it will be essential moving forwards to involve older adults in the design of such products. Additionally, understanding the impact of different protein sources on subsequent perception and acceptability as well as on nutritional and health outcomes."
Additionally, their findings confirm that older adults can have reduced appetite, modulated sensory sensitivity and oral impairments; therefore, products need to be developed and optimised accordingly.
"In terms of key design implications from a sensory perspective, products should avoid being mouthdrying and adhesive (such attributes/properties may intensify with age), should be optimised for sweetness, fat, viscosity, and mouthfeel (e.g., soft texture, minimal dryness and easy to chew) and utilise familiar or popular flavours," the report states.
"This should enable increased protein consumption (via familiar liquids, meals, or snacks) and a tailored and targeted approach could be key to promoting longevity and positive health outcomes in our ageing population."
The data reveals there are age-related differences relating to consumers’ ideal drink portion sizes, where older adults preferred a smaller portion size compared with younger adults. The authors say this is important as standard ONS portion sizes are typically around 125 to 220 mL and the older adults in the study preferred drink portion sizes of 180 ml. Therefore, optimising volume to improve compliance is a key aspect in ensuring widespread benefits of such products, the authors.
In contrast to drinks, there were no differences between age groups for the ideal cake portion sizes; older adults did not select smaller cake portion sizes than younger adults.
"This suggests such familiar snacks may be suitable for protein fortification and subsequently help promote protein consumption in our ageing population. It is likely that older adults would be willing to consume up to around 70 g of cake, or more in some cases, depending on the cake type," the report suggests.
The researchers give their suggestions as to why the older adults in their study consumed protein-fortified products infrequently.
"It is likely older adults are often confused by, lack knowledge of, and/or are unaware of, protein requirements.
"It should be noted that in some cases food neophobia could be a potential barrier to overcome for an ageing population, especially when consuming fortified products for the first time."
Consumers cited taste and flavour as key attributes for protein-fortified products and taste has been considered a driver for ONS dislike.
Therefore, the authors argue product designers need to ensure that fortified products deliver on both taste and flavour to help promote protein consumption.
The report adds: "A key finding from our study was that consumers considered cereals, pasta, porridge, biscuits, and cakes as products most preferred for protein fortification; such products can be regularly consumed at breakfast (cereals and porridge) or as snacks between meals (biscuits and cakes). These findings suggest that designing protein-fortified products based around the consumption moment (e.g., breakfast or snacks) could be a viable approach to encourage protein consumption for an ageing population."
This study involved an initial literature and market review coupled with two questionnaires. Seventy-three healthy (male (37%) and female (63%)) consumers from two age groups (41 younger adults: 18–30 years, 25.7 ± 3.2 years and 32 older adults: over 65 years, 74.6 ± 5.7 years) completed a series of questionnaires as part of a single blinded crossover trial (University of Reading Ethics Committee) involving two study visits.
The portion size questionnaire was designed to explore consumers’ ideal portion sizes relating to a series of popular and commonly consumed drinks and cakes in the UK. The protein fortification attitudes questionnaire aimed to understand consumption habits and preferences.
A literature and market review on protein-fortified products aimed to explore different food matrices regularly fortified with protein in three key areas: literature-based studies, Clinical settings, and the UK retail market.
14(23), 5083; https://doi.org/10.3390/nu14235083
"Promoting Protein Intake in an Ageing Population: Product Design Implications for Protein Fortification"
Norton. V., Lignou. S., and Methven. L.