Investigation of the impact of two aerobic exercise intensities on fat taste sensitivity, appetite, food preference and energy intake in women with different body composition

To investigate the effect of exercise at two different intensities on oral sensitivity to oleic acid (C18:1), fat perception, appetite, and energy intake in women with normal weight and overweight.

The study design is a cross-over clinical trial with three conditions (control, intervention 1, and intervention 2) conducted on 20 eligible women. All participants received all three conditions in a randomized order, with at least seven days between sessions. Randomization of session order was performed using a lottery method. The total sample size was 20 participants. Single-blind blinding (regarding the samples) was applied in the taste test sections of this trial.

Setting: Exercise Physiology Laboratory, Faculty of Sport Sciences, University of Guilan, Rasht, Iran. Study population: Women aged 18–35 years with a body mass index (BMI) of 18–30 kg/m², who had not engaged in regular physical activity during the previous three months and met the study eligibility criteria. Blinding: Single-blind for sensory assessments. Blinding procedure: During the sensory assessments, participants will be blinded to the type of samples provided.

Inclusion criteria: Women 18–35yrs; BMI 18–30; WHR < 0.85. Exclusion criteria: Regular physical activity in last 3 months; acute/chronic diseases; use of glucose‑, BP‑, lipid‑lowering, or cardiac meds; supplements/medications (dietary or sports‑related) in last 3 months; tobacco/alcohol use; history of bariatric surgery or weight instability (≥2 kg change) in last 3 months; history of rhinoplasty.

Control: no exercise; Intervention 1: 50–55% HRmax, 45 min; Intervention 2: 70–75% HRR, 30 min;

Oral sensitivity to oleic acid (C18:1), Fat Taste Ranking, Appetite Perception, Energy and Macronutrient Intake, Food Preference

This study employs a randomized crossover clinical trial design with three interventional arms and a baseline assessment phase, in which the unit of randomization is the individual participant. Following verification of eligibility criteria and obtaining signed informed consent, each participant is randomly assigned to one of six possible sequences for receiving the three interventions (namely ABC, ACB, BAC, BCA, CAB, and CBA). To ensure balanced distribution of participants across these six sequences, a balanced block randomization method is utilized. The generation of random sequences is the responsibility of an independent researcher who has no involvement in participant recruitment, intervention administration, or outcome assessment. This process is carried out using IBM SPSS Statistics version 27 software, based on computer-generated random numbers. The final allocation list remains confidential within the research team, and to conceal the allocation process, the sequence assigned to each participant is placed in opaque, light-proof, sealed, and sequentially numbered envelopes. Once the baseline assessments are completed for each individual and they are formally enrolled in the study, the envelope containing their registration number is opened by the principal investigator, revealing the order in which the interventions are to be administered for that participant. It is worth noting that prior to the opening of the envelopes, all researchers involved in recruitment, baseline evaluations, and data analysis remain blinded to the sequence assigned to each participant.

Participants are aware of the exercise intensity they receive and cannot be blinded to the exercise intervention. However, in the C18:1 taste test, participants are blinded to the type of samples (control or containing oleic acid) and cannot identify which sample contains C18:1.