Overweight and Obesity
Conditions
Brief summary
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.
Interventions
BEHAVIORALWater 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.
BEHAVIORALWater 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.
BEHAVIORALWater 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.
Sponsors
Virginia Polytechnic Institute and State University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
50 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
* aged 50+ years * BMI ≥25 kg/m2 * 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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Body weight change | weeks 0 to 12 in the weight loss phase, month 0 to 12 post weight loss phase | Body weight change in weight loss and weight loss maintenance phases |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in appetite sensations | weeks 0 to 12 in the weight loss phase, month 0 to 12 post weight loss phase | 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. |
| Change in hydration status | weeks 0 to 12 in the weight loss phase, month 0 to 12 post weight loss phase | 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. |
| Change in executive function (EF) | weeks 0 to 12 in the weight loss phase, month 0 to 12 post weight loss phase | Changes in EF (attention, inhibition) assessed using ePRIME computerized tasks, in weight loss and weight loss maintenance phases. These changes may mediate intervention adherence. |
Countries
United States
Contacts
PRINCIPAL_INVESTIGATORBrenda Davy, PhD RDN
Virginia Polytechnic Institute and State University
Outcome results
None listed