Effect of Meal Frequency on Diet Self-Efficacy and Perceived Stress in Women With Weight Cycling

NCT07582952 | Completed

• 2 other identifiers: AMU-EC143-2026EC-2026-143
• Study Type: interventional
• Target: 72
• Locations: 1 country
• Sites: 1

Brief Summary

The World Health Organization (WHO) defines obesity as abnormal or excessive fat accumulation in the body that may adversely affect health. In 2022, 1 in 8 people worldwide lived with obesity, while the adult obesity rate has more than doubled since 1990, and the adolescent obesity rate has quadrupled. Obesity is a risk factor for noncommunicable diseases such as type 2 diabetes, hypertension, cardiovascular diseases, cancer, and sleep apnea, and is associated with an increased risk of death. The treatment of obesity-related comorbidities, along with indirect costs resulting from lost productivity and premature death, contributes to the economic burden caused by obesity. Therefore, effective management of obesity is of critical importance for improving overall health outcomes and reducing the burden on healthcare systems. It has been demonstrated that a 5% reduction in body weight in individuals diagnosed with obesity can improve health outcomes, and this value has been established as a target standard for weight loss interventions. However, while dietary interventions can achieve clinically meaningful weight loss, weight regain is common due to a combination of low adherence to dietary strategies and compensatory physiological mechanisms that influence weight regain. Consequently, individuals may find themselves in a "weight cycle," losing weight and then regaining it. Weight maintenance is defined as intentional weight loss followed by the preservation of that loss for at least six months. It has been noted that the weight cycle complicates this process. The weight cycle defined as repeated periods of intentional weight loss followed by regain is considered a common yet poorly understood factor among obese individuals. The weight cycle is viewed as one of the major challenges in clinical obesity care. For this reason, it is emphasized that strategies aimed at preventing weight cycling or promoting weight maintenance have gained importance. Additionally, attention is drawn to psychological factors in eating behavior, with particular emphasis on the individual's self-confidence and stress levels being crucial for sustaining healthy eating behaviors. Individuals experiencing weight cycling often face challenges with diet adherence, sustainability, and stress management. Meal frequency strategies applied to these individuals can influence not only weight loss but also diet adherence and the psychological experience of the dietary process. Given the rise in obesity and obesity-related disorders, understanding the relationship between stress, self-efficacy, and food choice in young adulthood may offer insights into preventing adverse health outcomes in later life stemming from poor dietary habits. An appropriate meal schedule can help an individual adapt better to the diet and manage the process with less stress; thereby facilitating weight maintenance success and making healthy eating a lifestyle. However, in the treatment of obesity, data regarding different meal frequency approaches in dietary interventions remain controversial. The aim of this study is to examine the factors influencing the sustainability of the diet and the long-term maintenance of weight loss in individuals experiencing weight cycling. In this context, the effects of different meal frequencies on this process were evaluated; the study addressed not only physical outcomes but also psychological factors such as how individuals felt during the dietary process, their stress levels, and their self-confidence. Thus, the aim was to present a more comprehensive perspective by examining the relationship between meal frequency and weight management from both physiological and psychological dimensions.

Conditions

Weight Cycling; Obesity & Overweight; Dietary Self-efficiacy; Perceived Stress; Meal Frequency

Keywords

Meal Frequency; Dietary Intervention; Weight Management; weight cycle

Outcome Measures

Primary Outcomes (30)

• Body weight (kg)

  Body weight measured using a calibrated digital scale

  Baseline, Weeks 2, 4, 6, and 8, and 6 months post-intervention

• Body mass index (kg/m²)

  Calculated as body weight in kilograms divided by height in metres squared

  Baseline, Weeks 2, 4, 6, and 8, and 6 months post-intervention

• Height (cm)

  Height measured using a stadiometer with participants standing upright, feet together, in Frankfurt plane position.

  Baseline, Weeks 2, 4, 6, and 8, and 6 months post-intervention

• Waist circumference (cm)

  Waist circumference was measured using a non-stretch tape measure along the midline between the lowest rib and the iliac crest, with the individual standing with their feet together and arms at their sides in a relaxed position.

  Baseline, Weeks 2, 4, 6, and 8, and 6 months post-intervention

• Hip circumference (cm)

  Hip circumference was measured using a non-stretchable tape measure across the widest part of the hips, with the individual standing upright, feet together and arms at their sides

  Baseline, Weeks 2, 4, 6, and 8, and 6 months post-intervention

• Neck circumference (cm)

  During neck circumference measurements, participants were positioned upright with their arms at their sides and their feet together. The measurements were taken by the researcher, who stood opposite the participant, using a non-stretchable tape measure around the neck near the shoulder.

  Baseline, Weeks 2, 4, 6, and 8, and 6 months post-intervention

• waist-to-height ratio

  Waist-to-height ratio calculated by dividing waist circumference (cm) by height (cm).

  Baseline, Weeks 2, 4, 6, and 8, and 6 months post-intervention

• waist-to-hip ratio

  Waist-to-hip ratio calculated by dividing waist circumference (cm) by hip circumference (cm).

  Baseline, Weeks 2, 4, 6, and 8, and 6 months post-intervention

• basal metabolic rate (kcal)

  The measurements were taken using bioelectrical impedance analysis (BIA) with the INBODY 270 device.

  Baseline, Weeks 2, 4, 6, and 8, and 6 months post-intervention

• Body Fat mass (kg)

  The measurements were taken using bioelectrical impedance analysis (BIA) with the INBODY 270 device.

  Baseline, Weeks 2, 4, 6, and 8, and 6 months post-intervention

• Lean body mass (kg)

  The measurements were taken using bioelectrical impedance analysis (BIA) with the INBODY 270 device.

  Baseline, Weeks 2, 4, 6, and 8, and 6 months post-intervention

• Percentage of lean body mass(%)

  The measurements were taken using bioelectrical impedance analysis (BIA) with the INBODY 270 device.

  Baseline, Weeks 2, 4, 6, and 8, and 6 months post-intervention

• Body fat percentage (%)

  The measurements were taken using bioelectrical impedance analysis (BIA) with the INBODY 270 device.

  Baseline, Weeks 2, 4, 6, and 8, and 6 months post-intervention

• Total body water (L)

  The measurements were taken using bioelectrical impedance analysis (BIA) with the INBODY 270 device.

  Baseline, Weeks 2, 4, 6, and 8, and 6 months post-intervention

• Lipid accumulation product index-LAP

  Calculated using validated formulas based on anthropometric measurements and relevant biochemical parameters (waist circumference(cm) and triglycerides (mmol/L))

  Baseline, Week 8 and 6 months post-intervention

• Visceral adiposity index-VAI

  Calculated using validated formulas based on anthropometric measurements and relevant biochemical parameters (waist circumference (cm), body mass index(kg/m²),HDL-C (mmol/L) and triglycerides (mmol/L)).

  Baseline, Week 8 and 6 months post-intervention

• Conicity index - CI

  Calculated using validated formulas based on anthropometric measurements and relevant biochemical parameters (waist circumference (m),Body weight (kg), Height (m) )

  Baseline, Week 8 and 6 months post-intervention

• A body shape index-ABSI

  Calculated using validated formulas based on anthropometric measurements and relevant biochemical parameters (waist circumference (m), BMI(kg/m²) and heigh(m))

  Baseline, Week 8 and 6 months post-intervention

• Abdominal volume index-AVI

  Calculated using validated formulas based on anthropometric measurements and relevant biochemical parameters (waist circumference (cm), hip circumference (cm)).

  Baseline, Week 8 and 6 months post-intervention

• Body adiposity index-BAI

  Calculated using validated formulas based on anthropometric measurements and relevant biochemical parameters (Hip circumference (cm), Height (m)).

  Baseline, Week 8 and 6 months post-intervention

• Body roundness index-BRI

  Calculated using validated formulas based on anthropometric measurements and relevant biochemical parameters (Waist circumference (m), Height (m)).

  Baseline, Week 8 and 6 months post-intervention

• Anthropometric risk index-ARI

  Anthropometric Risk Score (ARS) is a composite score calculated by scoring each anthropometric parameter (BMI, waist circumference, waist-to-hip ratio, and waist-to-height ratio) based on established reference cutoff values and summing the individual scores.

  Baseline, Week 8 and 6 months post-intervention

• Fasting blood glucose (mg/dL)

  No additional blood samples were collected from participants. Biochemical data were obtained from existing health records, reflecting results from the previous 3 months, measured after a minimum 8-hour fasting period using standard laboratory methods.

  Baseline, Week 8 and 6 months post-intervention

• Triglycerides (mg/dL)

  No additional blood samples were collected from participants. Biochemical data were obtained from existing health records, reflecting results from the previous 3 months, measured after a minimum 8-hour fasting period using standard laboratory methods.

  Baseline, Week 8 and 6 months post-intervention

• Total cholesterol (mg/dL)

  No additional blood samples were collected from participants. Biochemical data were obtained from existing health records, reflecting results from the previous 3 months, measured after a minimum 8-hour fasting period using standard laboratory methods.

  Baseline, Week 8 and 6 months post-intervention

• HDL cholesterol (mg/dL)

  No additional blood samples were collected from participants. Biochemical data were obtained from existing health records, reflecting results from the previous 3 months, measured after a minimum 8-hour fasting period using standard laboratory methods.

  Baseline, Week 8 and 6 months post-intervention

• LDL cholesterol (mg/dL)

  No additional blood samples were collected from participants. Biochemical data were obtained from existing health records, reflecting results from the previous 3 months, measured after a minimum 8-hour fasting period using standard laboratory methods.

  Baseline, Week 8 and 6 months post-intervention

• Thyroid stimulating hormone (TSH) (µIU/mL)

  No additional blood samples were collected from participants. Biochemical data were obtained from existing health records, reflecting results from the previous 3 months, measured after a minimum 8-hour fasting period using standard laboratory methods.

  Baseline, Week 8 and 6 months post-intervention

• Alanine aminotransferase (ALT) (U/L)

  No additional blood samples were collected from participants. Biochemical data were obtained from existing health records, reflecting results from the previous 3 months, measured after a minimum 8-hour fasting period using standard laboratory methods.

  Baseline, Week 8 and 6 months post-intervention

• Aspartate aminotransferase (AST) (U/L)

  No additional blood samples were collected from participants. Biochemical data were obtained from existing health records, reflecting results from the previous 3 months, measured after a minimum 8-hour fasting period using standard laboratory methods.

  Baseline, Week 8 and 6 months post-intervention

Secondary Outcomes (3)

• perceived stress level

  Baseline, Week 8 and 6 months post-intervention

• dietary self-efficacy

  Baseline, Week 8 and 6 months post-intervention

• General Well-Being

  Baseline, Week 8 and 6 months post-intervention

Study Arms (2)

3 Meal Group

ACTIVE COMPARATOR

Participants followed a weight-loss diet consisting of 3 main meals per day.

Behavioral: 3-meal diet plan

6 Meal Group

EXPERIMENTAL

Participants followed a weight-loss diet consisting of 3 main meals and 3 snacks per day.

Behavioral: A dietary intervention comprising 3 main meals and 3 snacks

Interventions

3-meal diet plan BEHAVIORAL

A personalised weight-loss diet that reduces daily calorie intake by 500-700 kcal. Group 1 followed the diet for 8 weeks, consisting of 3 main meals a day.

3 Meal Group

A dietary intervention comprising 3 main meals and 3 snacks BEHAVIORAL

A personalised weight-loss diet that reduces daily calorie intake by 500-700 kcal. Group 1 followed the diet for 8 weeks, consisting of 3 main meals and 3 snacks per day.

6 Meal Group

Eligibility Criteria

• Age: 25 Years - 55 Years
• Sex: female
• Healthy Volunteers: No
• Age Groups: Adult (18-64)

You may qualify if:

• Female participants aged 25-55 years
• Body mass index (BMI) between 25 and 35 kg/m²
• having a history of weight fluctuations
• Willingness to participate and provide informed consent

You may not qualify if:

• Presence of cardiovascular disease
• Chronic kidney disease
• Hypertension
• Diagnosis of Type 1 or Type 2 diabetes mellitus
• Pregnancy or breastfeeding
• Use of any medication or dietary supplement for weight loss or fat reduction
• Engagement in intense physical activity
• No having a history of weight fluctuations
• Menopausal status
• Failure to attend scheduled follow-up visits
• Non-adherence to the intervention protocol for three consecutive days

Sponsors & Collaborators

• Ankara Medipol University: lead

Study Sites (1)

Ankara Medipol University

Ankara, Altındağ, Turkey (Türkiye)

Location

MeSH Terms

Conditions

Weight Cycling; Obesity; Overweight

Condition Hierarchy (Ancestors)

Weight Gain; Body Weight Changes; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Weight Loss; Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases

Study Officials

• Elif Dadak Yıldırım, PhD(c)

  Ankara Medipol University

  STUDY DIRECTOR

• İlknur G Yıldırım, Asst. Prof.

  Ankara Medipol University

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Professor

Model Details: The intervention phase of the study lasted 8 weeks. During the intervention period, face-to-face interviews were conducted every 2 weeks, and measurements were repeated. After the intervention was completed, the ability to maintain weight loss was assessed through a single measurement taken 6 months later. Two groups were formed using a simple randomization method (Group 1: 3 main meals; Group 2: 3 main meals + 3 snacks). In accordance with the recommendations, a weight loss program was implemented for each participant. Anthropometric measurements and body composition analyses were performed at weeks 0, 2, 4, 6, and 8, and 6 months after the intervention ended. While anthropometric measurements were performed using standard measurement techniques, body composition analyses were conducted using the INBODY 270 device. The biochemical data used in the study were obtained from laboratory results from the participants' health records covering the previous 3 months.

Study Record Dates

• First Submitted: April 30, 2026
• First Posted: May 13, 2026
• Study Start: August 4, 2025
• Primary Completion: October 1, 2025
• Study Completion: May 1, 2026
• Last Updated: May 13, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will not share

Locations

TU (1)