The goal of this randomized clinical trial is to study the effectiveness of protein supplements in frailty improvement, muscle strength, physical performance, energy intake and body composition of pre-frail elderly people. in Selangor, Malaysia.

The main question[s] it aims to answer are:

Does PS intervention significantly affect in frailty improvement, muscle strength, physical performance, energy intake and body composition of elderly people? For the interventional group, Participants will receive 30g of SUSTINEX Hydrolyzed Whey Protein. The participants will be asked to add it to their food or drinks to reach the goal of consuming 30g daily. For control group, participants will receive no intervention- usual care, will receive the standard care of the clinic without supplemented with PS.

Several studies stated that an increase in dietary protein consumption may help to prevent muscle loss and stimulate muscle protein synthesis. This study aims to study the effectiveness of protein supplements in frailty improvement, muscle strength, physical performance, energy intake and body composition of pre-frail elderly people. This study is a 3-months (12 weeks), single blind, parallel randomized controlled experiment with two arms in which outpatient persons in Serdang hospitals, Malaysia, are randomly assigned to one of two arms: a) control group (CG), and b) protein (PSG) supplementation in two of Selangor hospital's outpatients (Serdang Hospital, Hospital Pengajar UPM) Serdang, Malaysia. Study population are men or women elderlies who 60 years or more and classified (according to Fried criteria) as pre-frail older adults.

Sample size was calculated based on the findings of (Shahar et al., 2019), considering a mean ± SD of BMI in protein supplement study as 25.91 ± 2.96 kg/m2 in the placebo group and 23.82 ± 4.16 kg in protein supplement group, with a power of 80% and an α level (2-tailed) of 5%. This process conducted using G Software. This gave a sample size of 17 participants/group and total 34 participants. With an expected dropout rate of 20%, a sample size of 20 participants/group is considered adequate.

• Participants will be recruited from outpatient and Dietetics clinics patients who will be screened by the site investigators in both Serdang and HPUPM hospital using FRAIL Screen and demographic and health-related information will be collected.
• An information papers will be given and discussed following the invitation procedure. Individuals who agree to participate will be asked to submit written informed permission and will then be screened to determine their eligibility to participate. Individuals who have been assessed as eligible to participate will be invited to a pre-intervention data collection session (baseline assessment).
• After testing the eligibility, a random sequence will be generated for the patients' numbers which results in a sequence of random numbers divided in two groups.
• The allocation ratio is 1:1. To guarantee allocation concealment, the randomization will be carried out by an independent third party. The envelope will be opened on the spot, deciding which group the participant would be allocated to either Group 1 (PSG): Intervention Group or Group 2 (CG): Control Group.

Protein Supplement Group:

Participants will receive 30g of SUSTINEX Hydrolysed Whey Protein. The participants will be asked to add it to their soft food or their beverages to reach the goal of consuming 30g daily.

Control Group (CG) Receive no intervention- usual care, will receive the standard care of the clinic without supplemented with PS.

• Before entering the run-in period, the participants will be interviewed using a structured questionnaire to obtain information: Demographic data of participants, anthropometric measurements, practice function/performance, muscle strength activities, dietary intake (3-day food record) will all be done one week prior to the intervention period in order to get the baseline data.

Interventional group:

• All participants will be instructed on how to prepare and consume the protein supplements and how to record them in the provided compliance diaries.
• The supplement will be in powder form in individual sachets (15g per sachet) and subjects will be asked to mix 2 sachets daily in their soft foods or beverages (1 sachet in the morning & 1 sachet in the evening).

Supplements Supplying:

• Supplements will be handed to the participants in the dietetic clinic at the beginning of the trial and in the middle (6th week) of the trial and they will be asked to return the previous can in order to check the retain sachets.

Monitoring Process:

• Compliance diaries will be handed out to participants with instructions provided on how to complete them; specifically, they will be asked to record the timing and number of supplements consumed per day.
• The researcher will check compliance with the supplements prescription on a weekly- basis message reminder sent to each participant.
• According to the remained sachets and the dairies, if the study team identify that a participant's compliance to the planned number of protein sachets, is less than 70%, the researcher will respectively interview the participant to assess any difficulties and identify strategies that could facilitate compliance.

Follow-up Process:

• Participants should not take any over-the-counter medications without informing the researcher. They can continue taking the prescribed medications by their respective physicians.
• Adverse events (AEs), that is, any untoward medical occurrences will be investigated during all visits, whether or not they are related to the study product. The events will be reviewed by the study's investigator and participants will be referred to the research physician as required.

Data analysis The research design is structured on two assessments which involves the baseline and after the intervention. The characteristics of the baseline respondents (CG, PSG) will be reported. Missing data at random (MAR) method will be used treat data that are missing during intervention by way of intention to treat (ITT) as recommended by Dziura, Post, Zhao, Fu, & Peduzzi (2013).

Categorical variables will be summarized by frequencies and percentages, continuous variables will be summarized by means and standard deviation. Additionally, cross tabulation of the categorical variables will be done to verify the independency of some required variables targeted in the research objectives which will be verify via chi-square test or Fisher's exact test.

The continuous data will further be examined for conformity to normality distribution assumptions, the continuous data with non-normality characteristics will be summarized by the median (IQR). Non-parametric statistical methodology such as Mann Whitney, Wilcoxon signed rank test among other statistical methodologies will be adopted accordingly for non normal continuous variables.

Analysis of variance (ANOVA) on repeated measures for the second factor will be used to assess variability in weight loss, exhaustion, weakness, slowness and low activity between the baseline and intervention. Analysis of covariance (ANCOVA) via generalized linear model will be adopted for the post-intervention analysis. The sensitivity analysis will be examined through receiver operating characteristics (ROC) curves especially on variables that has missing data.

Inclusion Criteria:

• Pre-frail men or women aged 60 years and above (Fried criteria: score ≥1 but <3 out of 5).
• Willing to give informed consent to be randomized to either the protein supplement or control group
• Willing to follow the study protocol.

Exclusion Criteria:

• Non or Frail elderlies (Fried criteria)
• Diagnosed with chronic diseases include: (heart-related disease, COPD, stroke, cancer, asthma, renal dysfunction, terminally ill), bedridden.
• Already involved or still participating in any health interventional studies.
• Participants who consume protein supplements
• Any sustained fracture (hip, vertebrata) in past six month, any surgery (hip, abdominal area) in past six month