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

Overview

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.

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.