Protein Intake for Healthy Subjects

Recruiting in Toronto (>99 mi)

Overseen By Mahroukh Rafii, BSc

Age: Any Age

Sex: Any

Trial Phase: Academic

Sponsor: The Hospital for Sick Children

Must not be taking: Acetaminophen, Steroids

Disqualifiers: HIV, Diabetes, Cancer, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: Unknown

55 Participants Needed

Trial Summary

What is the purpose of this trial?

To measure the fractional and absolute synthesis rates of GSH, an antioxidant that protects cells from damage, in the erythrocytes of healthy school-aged children, young adults and old adults in response to graded intakes of protein in order to determine if increasing the protein intake above the current recommended DRI produces increases in the GSH synthesis rates in erythrocytes of these individuals. Participants will consume specially formulated diets with varying protein levels.

Will I have to stop taking my current medications?

If you are taking medications that affect GSH (an antioxidant) or protein metabolism, like acetaminophen or steroids, you will need to stop taking them to participate in this trial.

What data supports the effectiveness of the treatment Varying protein intakes, Protein supplementation, Dietary protein intake for healthy subjects?

Research shows that increased protein intake can promote health and recovery from illness, as well as maintain functionality in older adults. A study found that a protein-enriched diet helped hospitalized older adults meet recommended protein intake levels, suggesting potential benefits for maintaining health. ^{1 2 3 4 5}

Is protein supplementation safe for healthy older adults?

Research shows that protein supplementation in older adults is generally safe and does not negatively affect regular dietary intake, hunger, or appetite. Studies indicate that increasing protein intake can be beneficial for maintaining muscle mass and strength without adverse effects on energy intake or other health outcomes. ^{6 7 8 9 10}

How does varying protein intake as a treatment differ from other treatments for healthy subjects?

Varying protein intake is unique because it focuses on adjusting the amount and quality of protein in the diet to improve health outcomes like muscle mass, strength, and weight management, rather than using medications or supplements. This approach is particularly beneficial for older adults and athletes, as it can help prevent muscle loss and enhance performance without the side effects associated with drugs. ^{7 10 11 12 13}

Research Team

Glenda Courtney-Martin, PhD

Principal Investigator

Academic &Clinical Specialist

Eligibility Criteria

This trial is for healthy children over 22 kg, young adults aged 19-40 with a BMI under 25, and older adults aged 60-90 in good health with normal blood markers. Participants must be willing to have their diet and protein intake controlled and provide consent. Those on weight loss diets, with recent significant weight loss, chronic diseases affecting metabolism or unwilling to have blood drawn are excluded.

Inclusion Criteria

Healthy school-aged children

Body weight ≥ 22 kg

No history of anemia

Exclusion Criteria

You have lost a lot of weight in the past month.

You have lost a lot of weight in the past month or are following a diet to intentionally lose weight.

You have a long-term illness or recent sickness that affects how your body processes certain substances. This includes conditions like HIV, diabetes, cancer, liver or kidney disease, and having a cold or flu.

Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Adaptation

Participants consume low protein foods plus a milkshake drink for adaptation

2-3 days for children and young adults, 3 days for old adults

In-person visits at SickKids

Study Day

Participants consume hourly protein drinks or milkshake diets and special cookies

1 day

In-person visit at SickKids

Follow-up

Participants are monitored for safety and effectiveness after treatment

up to 24 months

Treatment Details

Interventions

• Varying protein intakes

Trial Overview The study aims to understand how different levels of protein intake affect the production of Glutathione (GSH), an important antioxidant in our cells. Healthy participants will consume diets formulated with varying amounts of protein to see if higher intakes boost GSH synthesis rates in red blood cells across different age groups.

Participant Groups

Group I: Protein intake Experimental Treatment 1 Intervention

Varying protein intakes.

Who Is Running the Clinical Trial?

The Hospital for Sick Children

Lead Sponsor

Trials

724

Recruited

6,969,000+

Findings from Research

In a study of 62 hospitalized adults aged 65 and older, only 17 patients achieved the recommended protein intake of ≥1.2 g/kg, highlighting a significant gap in meeting nutritional guidelines for older adults.

The medium/high risk group, which received a protein-enriched diet, had an average intake of 1.2 g/kg, while the low-risk group only averaged 0.9 g/kg, suggesting that a protein-enriched diet may be beneficial for all older hospitalized patients, regardless of malnutrition risk.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Protein intake in hospitalized older people with and without increased risk of malnutrition. Vasse, E., Beelen, J., de Roos, NM., et al.[2019]

In a study involving 84 hospitalized patients at nutritional risk, a novel protein-supplemented food service significantly increased the percentage of patients meeting their protein requirements (66% in the intervention group vs. 30% in the control group).

The intervention group also had a higher mean intake of energy and protein per body weight compared to the control group, indicating that the protein-supplemented food service effectively improved nutritional intake in these patients.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Positive effect of protein-supplemented hospital food on protein intake in patients at nutritional risk: a randomised controlled trial. Munk, T., Beck, AM., Holst, M., et al.[2014]

In a study of hospitalized patients at nutrition risk, combining a protein-enriched menu with individualized dietary counseling led to 92% of patients meeting over 75% of their energy requirements, compared to 76% in the historical intervention group.

The intervention group also showed a significant increase in mean energy and protein intake, with 31 kcal/kg and 1.2 g protein/kg, respectively, indicating that this combined approach is more effective than using a protein-enriched menu alone.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

From Evidence to Clinical Practice: Positive Effect of Implementing a Protein-Enriched Hospital Menu in Conjunction With Individualized Dietary Counseling. Munk, T., Bruun, N., Nielsen, MA., et al.[2018]

In a study of 2,853 mechanically ventilated ICU patients, higher protein and energy intake significantly reduced mortality and shortened time to discharge for high-risk patients, indicating the importance of tailored nutritional support in critical care.

For patients assessed as low-risk, increased nutritional intake did not show a significant impact on mortality or discharge times, suggesting that nutritional needs may vary based on individual risk levels.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Greater Protein and Energy Intake May Be Associated With Improved Mortality in Higher Risk Critically Ill Patients: A Multicenter, Multinational Observational Study. Compher, C., Chittams, J., Sammarco, T., et al.[2017]

Short-term oral protein-energy supplementation in moderately malnourished elderly patients significantly increased dietary intake (energy by 32% and protein by 65%) and fat-free mass (FFM) by 1.3 kg, indicating its efficacy in improving nutritional status.

The study highlights the importance of using Dual energy X-ray absorptiometry (DXA) to assess changes in FFM, as other methods like bio-impedance analysis and anthropometry did not accurately reflect these changes, suggesting a need for larger studies to confirm these findings.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Nutritional status after short-term dietary supplementation in hospitalized malnourished geriatric patients. Bos, C., Benamouzig, R., Bruhat, A., et al.[2007]

A study involving 24 adults aged 50-75 found that short-term supplementation with 20 g of whey protein did not affect overall energy or nutrient intake, regardless of whether it was taken in the morning or evening.

The protein supplement also did not change self-reported hunger or appetite levels, suggesting that this approach could help older adults increase their protein intake without negatively impacting their overall diet.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Short-Term Protein Supplementation Does Not Alter Energy Intake, Macronutrient Intake and Appetite in 50-75 Year Old Adults. Tuttiett, ER., Green, DJ., Stevenson, EJ., et al.[2022]

Protein supplementation in healthy older adults can lead to suppressed appetite ratings in acute studies, but overall energy intake (EI) may actually increase when considering the energy content of the protein supplements.

Longitudinal studies showed that while protein intake increased significantly, there was no significant difference in daily energy intake between protein and control groups, suggesting that protein supplementation can help boost protein consumption without negatively affecting overall appetite.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The Impact of Protein Supplementation on Appetite and Energy Intake in Healthy Older Adults: A Systematic Review with Meta-Analysis. Ben-Harchache, S., Roche, HM., Corish, CA., et al.[2023]

In a study involving 51 older adults with sarcopenia, personalized protein supplementation significantly increased total protein intake to 1.55 g·kg-1·d-1 without negatively impacting regular dietary protein or energy intake.

The supplementation improved the distribution of leucine intake across meals, particularly at breakfast and dinner, ensuring that participants received adequate amounts of this important amino acid without altering their usual dietary habits.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Personalized Protein Supplementation Improves Total Protein, Leucine, and Energy Intake in (Pre)Sarcopenic Community-Dwelling Older Adults in the ENHANce RCT. Dedeyne, L., Dupont, J., Verschueren, S., et al.[2021]

Older adults need higher protein intake than currently recommended, specifically 1.0 to 1.3 g/kg/day, to help maintain muscle mass and strength, especially when combined with resistance exercise.

Research shows that increased dietary protein significantly benefits lean mass gain and leg strength in older individuals, highlighting the importance of tailored nutrition for improving physical function in this age group.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Protein Requirements and Recommendations for Older People: A Review. Nowson, C., O'Connell, S.[2023]

A systematic review of 18 randomized controlled trials involving over 1300 older adults found that increasing protein intake may positively affect lean body mass, with some benefits for muscle strength when combined with physical exercise.

However, the evidence is insufficient to support significant health benefits from increased protein intake in older adults already consuming ≥0.8 g/(kg BW · d), particularly for outcomes like physical performance and bone health.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Health Effects of Increasing Protein Intake Above the Current Population Reference Intake in Older Adults: A Systematic Review of the Health Council of the Netherlands. Hengeveld, LM., de Goede, J., Afman, LA., et al.[2023]

Higher protein intake, specifically between 1.2 to 1.6 g/(kg·day), is associated with better health outcomes, including prevention of age-related muscle loss (sarcopenia) and improved weight management.

Increased protein consumption enhances satiety and supports athletic performance by aiding muscle recovery, with no evidence linking high protein diets to kidney disease or negative effects on bone health.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Protein "requirements" beyond the RDA: implications for optimizing health. Phillips, SM., Chevalier, S., Leidy, HJ.[2022]

The Recommended Dietary Allowance for protein is 0.8 g per kg of body weight per day for healthy adults, but higher intakes of 1.0 to 1.6 g per kg are recommended for those with varying levels of physical activity to support muscle growth and strength.

While long-term protein intake of up to 2 g per kg per day is considered safe, exceeding this amount may lead to health issues such as digestive and renal problems, highlighting the importance of both the quantity and quality of protein in the diet.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Dietary protein intake and human health. Wu, G.[2016]

The Dietary Reference Intake (DRI) recommends a protein intake of 0.8 g/kg/day for adults, but athletes may require more due to their higher activity levels, although this is not officially recognized in the RDA.

Higher protein diets (30%-35% of total energy) have been shown to promote greater weight loss and fat loss while preserving lean muscle mass compared to lower protein diets, making them beneficial for both athletes and individuals aiming for weight reduction.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Dietary protein for athletes: from requirements to metabolic advantage. Phillips, SM.[2022]

References

1. England pubmed.ncbi.nlm.nih.gov

Protein intake in hospitalized older people with and without increased risk of malnutrition. [2019]

2. England pubmed.ncbi.nlm.nih.gov

Positive effect of protein-supplemented hospital food on protein intake in patients at nutritional risk: a randomised controlled trial. [2014]

3. United States pubmed.ncbi.nlm.nih.gov

From Evidence to Clinical Practice: Positive Effect of Implementing a Protein-Enriched Hospital Menu in Conjunction With Individualized Dietary Counseling. [2018]

4. United States pubmed.ncbi.nlm.nih.gov

Greater Protein and Energy Intake May Be Associated With Improved Mortality in Higher Risk Critically Ill Patients: A Multicenter, Multinational Observational Study. [2017]

5. England pubmed.ncbi.nlm.nih.gov

Nutritional status after short-term dietary supplementation in hospitalized malnourished geriatric patients. [2007]

6. Switzerland pubmed.ncbi.nlm.nih.gov

Short-Term Protein Supplementation Does Not Alter Energy Intake, Macronutrient Intake and Appetite in 50-75 Year Old Adults. [2022]

7. United States pubmed.ncbi.nlm.nih.gov

The Impact of Protein Supplementation on Appetite and Energy Intake in Healthy Older Adults: A Systematic Review with Meta-Analysis. [2023]

8. Switzerland pubmed.ncbi.nlm.nih.gov

Personalized Protein Supplementation Improves Total Protein, Leucine, and Energy Intake in (Pre)Sarcopenic Community-Dwelling Older Adults in the ENHANce RCT. [2021]

9. Switzerland pubmed.ncbi.nlm.nih.gov

Protein Requirements and Recommendations for Older People: A Review. [2023]

10. United States pubmed.ncbi.nlm.nih.gov

Health Effects of Increasing Protein Intake Above the Current Population Reference Intake in Older Adults: A Systematic Review of the Health Council of the Netherlands. [2023]

11. Canada pubmed.ncbi.nlm.nih.gov

Protein "requirements" beyond the RDA: implications for optimizing health. [2022]

12. England pubmed.ncbi.nlm.nih.gov

Dietary protein intake and human health. [2016]

13. Canada pubmed.ncbi.nlm.nih.gov

Dietary protein for athletes: from requirements to metabolic advantage. [2022]