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Active, Not Recruiting

NCT Number: NCT07726394

Effects of a Six-Day Whole-Diet Intervention on Taste Perception and Dietary Behaviour in Young Adults

This study aims to investigate the effects of a specific diet modification on the pleasantness, desire, and saltiness intensities of selected foods and an ad libitum breakfast buffet through a randomized controlled trial with three arms. Participants will be randomized to either increase, decrease, or make no change to their daily intake of foods with a specific taste for six consecutive days, and outcomes will be assessed at two time points, at baseline (Day 1) and after the intervention (Day 7), alongside measures of adherence to the assigned diet. Each participant will receive an instruction to modify specific aspects of their diets for six days. This study is crucial for addressing diet-related health issues such as obesity, diabetes, and hypertension in Malaysia. By providing robust evidence on the effectiveness of specific diet modifications, the study can inform public health policies, improve dietary recommendations tailored to Malaysian cultural preferences, and promote long-term benefits.

Active, Not Recruiting

This study is active but is not currently recruiting participants.

Key information

Conditions

Sodium Excess Cardiovascular Diseases Hypernatremia Hypertension Metabolic Diseases Nutritional and Metabolic Diseases Salty Taste Vascular Diseases Water-Electrolyte Imbalance

Age range

18 year–35 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Department of Biomedical Sciences, Sir Jeffrey Cheah Sunway Medical School, Faculty of Medical and Life Sciences, Sunway University,.

Subang Jaya, Selangor, 47500, Malaysia

About this study

Excess dietary sodium intake is a major modifiable risk factor for hypertension and cardiovascular disease. Public health strategies often assume that reducing exposure to salty foods will lower salt preference and encourage healthier food choices through sensory adaptation; however, evidence from whole-diet interventions conducted under real-world conditions remains limited and inconsistent. Dietary sodium consumption substantially exceeds recommended levels in many countries, including Malaysia, and contributes to the global burden of hypertension and cardiovascular disease. Public health sodium reduction programmes are based on the premise that lowering exposure to salty foods can gradually shift taste preferences towards less salty diets through sensory adaptation. However, evidence supporting this mechanism is mixed, and most previous studies have relied on controlled laboratory settings, single foods, or salt solutions rather than whole-diet interventions.

The study aims to determine whether short-term changes in dietary sodium exposure are sufficient to modify salt taste perception and related eating behaviors and to identify factors associated with individual variation in these responses. The primary objective is to determine whether increasing or decreasing exposure to salty foods over six days alters salt-related taste perception compared with maintaining usual dietary habits. Secondary objectives are to examine changes in sodium intake and appetite-related outcomes and to explore demographic and anthropometric factors associated with taste perception responses. The findings will improve understanding of short-term sensory adaptation to dietary sodium exposure and provide evidence relevant to sodium reduction policies, food reformulation efforts, and behavioral interventions aimed at reducing population sodium intake.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Being a student or staff member of Sunway University or Sunway College
  • Aged 18-35 years
  • Able to communicate in English
  • Regularly consuming breakfast
  • Being willing and able to comply with all study procedures.

Exclusion criteria

  • Vegan/smokers/with chronic medical conditions (e.g., hypertension or diabetes)
  • Food allergies
  • Pregnant or breastfeeding
  • Currently dieting or attempting to lose weight
  • History of smell or taste impairment
  • Use medications or supplements that could affect taste perception.

Treatment and study plan

Experimental: Increased Salty Food Intake

Other

Participants assigned to the increase group were instructed to increase their consumption of salty-tasting foods and beverages for six consecutive days (Days 1-6) while living in their usual environment. Participants selected their own foods and beverages but were encouraged to choose options consistent with a higher-salt dietary pattern. Written guidance and meal examples were provided to support implementation. Outcomes were assessed at baseline (Day 1) and after the intervention (Day 7).

Experimental: Decrease Salty Food Intake

Other

Participants assigned to the decrease group were instructed to reduce their consumption of salty-tasting foods and beverages for six consecutive days (Days 1-6). Participants selected their own foods and beverages while attempting to minimize intake of high-salt items according to written guidance and examples. Outcomes were assessed at baseline (Day 1) and after the intervention (Day 7).

A six-day, self-directed dietary intervention designed to reduce exposure to salty foods and beverages under free-living conditions. Participants modified their habitual diet without direct provision of foods by the investigators

Active Comparator: Maintain Usual Diet

Other

Participants assigned to the maintain group were instructed to continue their usual eating habits and dietary practices for six consecutive days without making deliberate changes to salty food consumption. Outcomes were assessed at baseline (Day 1) and after the intervention (Day 7).

A six-day control condition in which participants maintained their habitual dietary intake under free-living conditions.

Primary outcomes

  1. Pleasantness

    Time frame: Pleasantness ratings will be collected at baseline (Day 1) and Day 7

    Pleasantness ratings, indicated after tasting three salty foods (Foods 1-3) and three non-salty foods (Foods 4-6), will be measured on a 10-point Likert scale.

    The rating scores will be averaged across the six test foods to generate composite scores. The aggregated pleasantness score will be used to capture overall taste responses rather than food-specific effects, consistent with whole-diet taste exposure theory.

  2. Desire to eat

    Time frame: Desire to eat ratings will be collected at baseline (Day 1) and Day 7

    Desire to eat ratings, indicated after tasting three salty foods (Foods 1-3) and three non-salty foods (Foods 4-6), will be measured on a 10-point Likert scale.

    The rating scores will be averaged across the six test foods to generate composite scores. The aggregated pleasantness score will be used to capture overall taste responses rather than food-specific effects, consistent with whole-diet taste exposure theory.

  3. Saltiness intensity

    Time frame: Saltiness intensity ratings will be collected at baseline (Day 1) and Day 7

    Saltiness intensity ratings, indicated after tasting three salty foods (Foods 1-3) and three non-salty foods (Foods 4-6), will be measured on a 10-point Likert scale.

    The rating scores will be averaged across the six test foods to generate composite scores. The aggregated pleasantness score will be used to capture overall taste responses rather than food-specific effects, consistent with whole-diet taste exposure theory.

Secondary outcomes

  1. Dietary sodium intake

    Time frame: Dietary sodium intake is estimated at baseline (Day 1) and Day 7

    Dietary sodium intake will be estimated from pre- and post-foods consumed by each participant.

  2. Sodium Density

    Time frame: Sodium density will be assessed at baseline (Day 1) and Day 7

    Sodium density (mg/g) will be computed to distinguish compositional from volumetric changes in sodium intake.

  3. Appetite

    Time frame: Appetite will be assessed at the baseline (Day 1) and Day 7

    Appetite will be rated on 0-10 Likert scales at the start of each test session.

  4. Adherence

    Time frame: Adherence was assessed only on Day 7

    Adherence is a self-reported measure rated on a 10-point Likert scale.

Sponsors and collaborators

Lead sponsor

Sunway University

Other

Registry information

Official study title

Effects of a Six-Day Whole-Diet Intervention on Taste Perception, Dietary Behaviour, and Individual Differences in Young Adults

Important dates

Study start
2026
Primary completion
2026
Study completion
2026
First posted
Jul 24, 2026
Registry last updated
Jul 24, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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