Impact of Different Types of Higher Dietary Protein Intake on Sleep Quality in Singapore Older Adults

NCT05400005 | Active Not Recruiting

• 1 other identifier: S19
• Study Type: interventional
• Target: 54
• Locations: 1 country
• Sites: 1

Brief Summary

Today, insufficient sleep has become a growing global problem. Sleep is essential to health and changes in sleep patterns are a part of the aging process. Inadequate and low-quality sleep also increases the risk for age-related cognitive decline and disease conditions. More importantly, due to COVID-19 health emergency, there is a significant increase of psychological distress and symptoms of mental illness and a worsening of quality of sleep. Therefore, there is an urgent need to investigate the way of improving sleep quality, in particular during and post COVID-19 period, in older adults. One of the possible strategies in improving sleep quality with lifestyle modification is having higher-protein diet. However, this effect has not been fully elucidated in older adults. In addition, the effect of type of dietary protein on sleep quality is inconclusive and there is no clinical trial which assessed the differential response in sleep quality between animal-sourced protein vs. plant-sourced protein. Therefore, the purpose of this research project is to assess the impact of different types of higher dietary protein intake on sleep quality in Singapore older adults. Findings from the proposed research will provide the scientific evidence of the beneficial effects of regularly consuming higher-protein diet on sleep quality in Singapore older adults. In addition, this research may validate the differential effect of different type of dietary protein on sleep quality. The results from the proposed research will also assist a practical guidance of nutritional behaviour changes providing sleep promoting effects to a large proportion of the Singapore population.

Conditions

Sleep; Gut Microbiome; Cardiometabolic Risk

Keywords

Dietary protein

Outcome Measures

Primary Outcomes (5)

• Change in sleep quality assessed by validated sleep questionnaires

  Pittsburgh Sleep Quality Index Questionnaire (PSQI) will be used to assess the sleep quality. Overall score ranging from 0 to 21 points, where lower scores denote a healthier sleep quality.

  Every 4 weeks (week 0, week 4, week 8, week 12 and week 16)

• Change in sleep quality assessed by electronic equipment

  An electronic equipment, actigraphy, will be used to assess the sleep quality, including sleep timing and wake up timing.

  Every 4 weeks (week 0, week 4, week 8, week 12 and week 16)

• Change in blood amino acid concentration

  Amino acid concentration in the blood will be measured

  Every 8 weeks (week 0 , week 8 and week 16)

• Change in blood serotonin concentration

  Serotonin concentration in the blood will be measured

  Every 8 weeks (week 0 , week 8 and week 16)

• Change in urinary 6-sulfatoxymelatonin (aMT6s) concentration

  6-sulfatoxymelatonin (aMT6s) concentration in the urine samples will be measured

  Every 8 weeks (week 0 , week 8 and week 16)

Secondary Outcomes (27)

• Change in fecal microbiome composition

  Every 8 weeks (week 0 , week 8 and week 16)

• Change in fecal short chain fatty acid (SCFA) concentration

  Every 8 weeks (week 0 , week 8 and week 16)

• Change in serum lipopolysaccharide binding protein (LBP) concentration

  Every 8 weeks (week 0 , week 8 and week 16)

• Change in blood short chain fatty acid (SCFA) concentration

  Every 8 weeks (week 0 , week 8 and week 16)

• Change in fecal bile acids

  Every 8 weeks (week 0 , week 8 and week 16)

Study Arms (3)

Normal protein diet (control)

NO INTERVENTION

Subjects are to consume normal-protein diet based on the "My Healthy Plate" diet (launched by Health Promotion Board of Singapore) for the duration of the 16-week study.

High protein diet (soy)

EXPERIMENTAL

Subjects are to consume higher-protein diet by following the "My Healthy Plate" diet (launched by Health Promotion Board of Singapore) and 20g of soy protein isolate for the duration of the 16-week study.

Other: Dietary protein

High protein diet (Micellar Casein)

EXPERIMENTAL

Subjects are to consume higher-protein diet by following the "My Healthy Plate" diet (launched by Health Promotion Board of Singapore) and 20g of micellar casein isolate for the duration of the 16-week study.

Other: Dietary protein

Interventions

Dietary protein OTHER

Intervention of the study include consuming a higher protein diet. Depending on the group allocation, this is done by asking the subjects to follow "My Healthy Plate" diet and consumption of 20g of protein isolates (casein or soy).

High protein diet (Micellar Casein); High protein diet (soy)

Eligibility Criteria

• Age: 60 Years - 85 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Adults 60-85 years old
• Not following HPB diet

You may not qualify if:

• Weight change \> 3kg in the past 3 months
• Exercise vigorously over the past 3 months
• Drinking more than 2 alcoholic drinks per day
• (if applicable) Pre-menopausal women
• Taking dietary supplements or medications which may impact sleep outcomes (e.g. Nutritional Shakes (e.g. Ensure), Trp, 5-HTP or melatonin supplementations) the past 1 month
• Taking dietary supplements which may impact the gut microbiota (e.g. antibiotics, prebiotics, probiotics) the past 2 months (a list of fermented foods)
• Impaired renal function (normal values: estimated glomerular filtration rate ≥ 90 mL/min/1.73 m2 calculated by chronic kidney disease epidemiology collaboration equation; CKD EPI)
• Soy intolerance and/or allergy or any medical conditions that may be affected by consumption of soy products (e.g. gout)
• Prescribed and taking antihypertensive/cholesterol-lowering/ type-2 diabetic medication or Chinese medicine herb which started less than 3 years prior to the intervention participation
• Diagnosed with gut/gastrointestinal issues such as lactose intolerance and irritable bowel syndrome (IBS)

Sponsors & Collaborators

• National University of Singapore: lead

Study Sites (1)

National University of Singapore

Singapore, 117546, Singapore

Location

Related Publications (6)

• Cappuccio FP, D'Elia L, Strazzullo P, Miller MA. Sleep duration and all-cause mortality: a systematic review and meta-analysis of prospective studies. Sleep. 2010 May;33(5):585-92. doi: 10.1093/sleep/33.5.585.

  PMID: 20469800 BACKGROUND

• Sutanto CN, Wang MX, Tan D, Kim JE. Association of Sleep Quality and Macronutrient Distribution: A Systematic Review and Meta-Regression. Nutrients. 2020 Jan 2;12(1):126. doi: 10.3390/nu12010126.

  PMID: 31906452 BACKGROUND

• Zhou J, Kim JE, Armstrong CL, Chen N, Campbell WW. Higher-protein diets improve indexes of sleep in energy-restricted overweight and obese adults: results from 2 randomized controlled trials. Am J Clin Nutr. 2016 Mar;103(3):766-74. doi: 10.3945/ajcn.115.124669. Epub 2016 Feb 10.

  PMID: 26864362 BACKGROUND

• Rosenfield AT, Zeman RK, Cronan JJ, Kay CJ. Ultrasound in the evaluation of renal masses. Conn Med. 1980 Jan;44(1):1-5. No abstract available.

  PMID: 7353359 BACKGROUND

• St-Onge MP, Crawford A, Aggarwal B. Plant-based diets: Reducing cardiovascular risk by improving sleep quality? Curr Sleep Med Rep. 2018 Mar;4(1):74-78. Epub 2018 Feb 5.

  PMID: 29910998 BACKGROUND

• Yao Y, Mak IE, Sutanto CN, Leong ZN, He Q, Pahwa U, Ling LH, Khoo CM, Ackers-Johnson MA, Foo RS, Kim JE. Impact of quantity and source of dietary protein intake within a healthy dietary pattern on cardiovascular disease risk factors in Singapore older adults: a randomized controlled trial. Food Funct. 2025 Dec 8;16(24):9533-9544. doi: 10.1039/d5fo03817k.

  PMID: 41284351 DERIVED

MeSH Terms

Interventions

Dietary Proteins

Intervention Hierarchy (Ancestors)

Proteins; Amino Acids, Peptides, and Proteins; Food; Diet, Food, and Nutrition; Physiological Phenomena; Food and Beverages

Study Officials

• Jung Eun Kim, PhD

  National University of Singapore

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: BASIC SCIENCE
• Intervention Model: FACTORIAL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Professor

Model Details: This is a 16-week factorial study design with subjects randomly assigned to consume normal-protein diet, higher-protein diet with micellar casein protein isolates or higher-protein diet with soy protein isolates. Subjects' sleep quality will also be evaluated and screened using the PSQI questionnaire (GSS ≤5 \[good sleepers\] vs. GSS \>5 \[poor sleepers\]). Sixty-eight older men and women (aged 60-85y, approximately half men and half women) will be recruited with the expectation that ≥ 54 subjects (≥ 18 subjects per group) will complete the study (≤ 20% dropout rate). The 18 subjects recruited for each of the intervention group were further classified into poor (n=9) and good sleepers (n=9).

Study Record Dates

• First Submitted: May 27, 2022
• First Posted: June 1, 2022
• Study Start: February 1, 2023
• Primary Completion: October 22, 2024
• Study Completion: December 1, 2025
• Last Updated: September 10, 2025

Record last verified: 2025-09

Data Sharing

• IPD Sharing: Will not share

Locations

SG (1)