Water Intake and Weight Control in Older Adults

This study is a randomized controlled intervention trial in adults aged 50+ years with overweight or obesity, which will compare three groups with different diet prescriptions: 1) pre-meal water consumption (500 ml, before each main meal) with a hypocaloric diet; 2) 1500 ml water consumed throughout the day with a hypocaloric diet; 3) hypocaloric diet with no instructions regarding water consumption. Smart water bottles will objectively assess water intake timing and volume. Urine osmolality, urine volume, and serum osmolality will be used as objective indicators of compliance with the water intake prescription. We will investigate changes in perceived hunger and fullness and appetite-regulating hormones as potential mechanisms by which premeal water could improve appetite regulation. We will also investigate the impact of water consumption and hydration on executive function capabilities, which may influence intervention adherence. Although increasing water intake could be an effective weight management strategy, no evidence-based recommendations exist for the timing of water intake needed for this benefit.

Study Overview

• Status: Recruiting
• Conditions: Overweight and Obesity
• Intervention / Treatment: Behavioral: Water intake and weight control in older adults - Premeal Water + hypocaloric diet; Behavioral: Water intake and weight control in older adults - Total Daily Water + hypocaloric diet; Behavioral: Water Intake and weight control in older adults - hypocaloric diet alone

• Study Type: Interventional
• Enrollment (Estimated): 375
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Brenda Davy, PhD RDN; Phone Number: 540-231-6784; Email: bdavy@vt.edu
• Study Contact Backup: Name: Elaina Marinik, PhD; Phone Number: 540-231-0923; Email: emarinik@vt.edu

Study Locations

• United States
  • Virginia
    • Blacksburg, Virginia, United States, 24061
      • Recruiting
      • Virginia Tech
      • Contact: Brenda M Davy, PhD; Phone Number: 540-231-6784; Email: bdavy@vt.edu
      • Contact: Elaina L Marinik, PhD; Email: emarinik@vt.edu
      • Principal Investigator: Brenda M Davy, PhD, RD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• aged 50+ years
• BMI 25-40
• weight stable (+/- 2 kg) in past 6 months
• willing to provide consent and comply with study protocol

Exclusion Criteria:

• usual plain drinking water intake >1500 ml/d
• uncontrolled hypertension (>159/99 mmHg)
• medical condition requiring specialized diet prescription (eg, T2D, CHF wih fluid restriction)
• medical condition that precludes participating in a physical activity program (eg, orthopedic injury)
• current or history of GI disease (eg, Crohn's), GI surgery, or medications which impact GI function
• allergies or aversions to foods included in the test meals

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Pre-meal water + Hypocaloric diet; premeal water ( 500 ml) before each main meal, three times per day + hypocaloric diet	Behavioral: Water intake and weight control in older adults - Premeal Water + hypocaloric diet; Individuals will be randomly assigned to one of three groups. All individuals will receive counseling in a structured hypocaloric meal plan (1200-1500 kcal) that is consistent with a healthy dietary pattern as described by the Dietary Guidelines for Americans. This group will receive specific instructions for daily water intake timing and volume.
Experimental: Daily water + Hypocaloric diet; total daily water prescription (1500 ml/d) + hypocaloric diet	Behavioral: Water intake and weight control in older adults - Total Daily Water + hypocaloric diet; Individuals will be randomly assigned to one of three groups. All individuals will receive counseling in a structured hypocaloric meal plan (1200-1500 kcal) that is consistent with a healthy dietary pattern as described by the Dietary Guidelines for Americans. This group will receive specific instructions for total daily water intake.
Active Comparator: Hypocaloric Diet alone; hypocaloric diet with not instructions regarding water intake	Behavioral: Water Intake and weight control in older adults - hypocaloric diet alone; Individuals will be randomly assigned to one of three groups. All individuals will receive counseling in a structured hypocaloric meal plan (1200-1500 kcal) that is consistent with a healthy dietary pattern as described by the Dietary Guidelines for Americans. This group will receive instructions in the hypocaloric diet, without specific fluid intake recommendations.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Body weight change	Body weight change in weight loss and weight loss maintenance phases	weeks 0 to 12 in the weight loss phase, month 0 to 12 post weight loss phase

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in appetite sensations	Changes in hunger and fullness, assessed using 100mm Visual Analog Scales (VAS), in weight loss and weight loss maintenance phases. These changes may mediate adherence to the hypocaloric diet and weight loss outcomes.	weeks 0 to 12 in the weight loss phase, month 0 to 12 post weight loss phase
Change in hydration status	Changes in hydration status, assessed using urine and serum osmolality, urine specific gravity, and serum sodium, in weight loss and weight loss maintenance phases. These changes may mediate intervention adherence.	weeks 0 to 12 in the weight loss phase, month 0 to 12 post weight loss phase
Change in executive function (EF)	Changes in EF (attention, inhibition) assessed using ePRIME computerized tasks, in weight loss and weight loss maintenance phases. These changes may mediate intervention adherence.	weeks 0 to 12 in the weight loss phase, month 0 to 12 post weight loss phase

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes in appetite hormones	Changes in appetite hormones, specifically blood concentrations of ghrelin, PYY 3-36, leptin, and CCK in response to a standardized test meal with an energy content of 25% estimated energy requirements.	weeks 0 to 12 in the weight loss phase, month 0 to 12 post weight loss phase

Collaborators and Investigators

• Sponsor: Virginia Polytechnic Institute and State University
• Investigators: Principal Investigator: Brenda Davy, PhD RDN, Virginia Polytechnic Institute and State University

Study record dates

Study Major Dates

• Study Start (Actual): November 13, 2023
• Primary Completion (Estimated): June 30, 2027
• Study Completion (Estimated): March 31, 2028

Study Registration Dates

• First Submitted: April 12, 2023
• First Submitted That Met QC Criteria: April 24, 2023
• First Posted (Actual): May 6, 2023

Study Record Updates

• Last Update Posted (Actual): December 5, 2023
• Last Update Submitted That Met QC Criteria: December 1, 2023
• Last Verified: December 1, 2023

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Overnutrition; Nutrition Disorders; Body Weight; Overweight
• Other Study ID Numbers: 22-624

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No