The purpose of the screening visit is to assess whether the individual is eligible to take part in the NUTRIMAL Project. Information on who is eligible to take part in the study is shown on one of our previous posts.
To be eligible for the study the participant must have low muscle mass and/or low strength so this is the first thing we measure.
How we screen for low muscle strength
We screen for low muscle strength by asking the participant to squeeze a device (called a handgrip dynamometer) as hard as possible! If a man squeezes less than 30 kg or a women squeezes less than 20 kg this means their strength is low.
How we screen for low muscle mass
We measure how much muscle the person has in their body using bioelectrical impedance analysis (BIA).
How the BIA works
The participant stands on the BIA monitor in bare feet and holds on to a rail. A very low, safe (completely painless!!) electrical signal is sent through the body.
The electrical signal passes quickly through tissues that are high in water content (i.e. muscle) the signal but meets resistance when it hits fat tissue. This resistance is measured and is used to calculate how much muscle is in the body.
If the participant has low strength and/or muscle mass we go on to the next phase of the screening visit:
Medical history questionnaire
We ask about the person’s medical history. This helps us to ensure that it is safe for the participant to take part. In addition, some medical conditions are associated with muscle wasting (i.e. COPD, cancer, liver failure). The muscle wasting with these conditions may not respond to the NUTRIMAL drinks in the same way as age-related muscle loss, and because of this participants with these conditions are not eligible for the study.
We also ask what medications the participant is on. There are certain medications that can affect muscle and may prevent us from seeing a beneficial effects of the drinks so unfortunately participants on these medications cannot take part (i.e. steroids, hormone replacements and suppressants, some cholesterol medications).
We ask the participant what they eat in a usual day. We are particularly interested in how much protein the participant usually eats at breakfast. Previous research has shown that older adults need more protein than younger adults to maximize their rate of muscle building and should aim to consume ~30 g of protein at each meal.
However, dietary surveys show that older adults often consume less than this – especially at breakfast.
In the NUTRIMAL Project we are aiming to boost protein at breakfast using the supplemental drinks. However, if someone is already eating a sufficient amount of protein at breakfast then the drinks are unlikely to have a beneficial effect on muscle. Therefore people already eating high protein breakfasts are not eligible for the study.
This helps us to ensure each participant has the cognitive capacity to fully understand the study procedures and to make an informed and rationale decision about whether or not they want to take part in the study.
The screening visit takes about 1 hour in total.