Appetite Regulation, Circadian Rhythm, Meal Timing, Metabolic Health, Obesity, Overweight
Conditions
Keywords
circadian rhythm, appetite, Meal Timing, obesity, Glucose Metabolism
Brief summary
This study investigates whether the timing of energy intake during the day-specifically consuming more calories at breakfast or at dinner-affects body measurements, blood sugar levels, cholesterol, and feelings of hunger in women who are overweight or obese. A total of 28 women participated in the study and were randomly assigned to one of two diet plans: one group consumed half of their daily calories at breakfast, while the other consumed them at dinner. Both groups followed a calorie-restricted diet for six weeks. The goal of this research is to understand whether eating more in the morning rather than in the evening leads to better outcomes for weight control and metabolic health. Findings from this study may help health professionals make more effective meal timing recommendations for weight loss and improving blood sugar regulation.
Interventions
BEHAVIORALBreakfast-Loaded Hypocaloric Diet
Participants in this group consumed a hypocaloric diet in which 50% of daily energy intake was provided at breakfast, 35% at lunch, and 15% at dinner. Meal times were standardized as follows: breakfast (7:00-9:00), lunch (12:00-14:00), and dinner (18:00-20:00). The diet was individually tailored and provided 20% fewer calories than the participants' total energy expenditure. Macronutrient distribution followed recommended guidelines: 45-60% carbohydrates, 10-20% protein, and 20-35% fat.
BEHAVIORALDinner-Loaded Hypocaloric Diet
Participants in this group consumed a hypocaloric diet in which 15% of daily energy intake was provided at breakfast, 35% at lunch, and 50% at dinner. Meal times were standardized as follows: breakfast (7:00-9:00), lunch (12:00-14:00), and dinner (18:00-20:00). The diet was individually tailored and provided 20% fewer calories than the participants' total energy expenditure. Macronutrient distribution followed recommended guidelines: 45-60% carbohydrates, 10-20% protein, and 20-35% fat.
Sponsors
Melike Nur Eroğlu
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
FEMALE
Age
20 Years to 45 Years
Healthy volunteers
Yes
Inclusion criteria
* Women aged 20-45 * BMI ≥25 kg/m² * Regular menstrual cycle * No chronic disease or medication use * PSQI ≤5 (Good sleep quality)
Exclusion criteria
* Pregnancy or lactation * Gastrointestinal or metabolic disorders * Shift workers, sleep disorders * Medication affecting metabolism * Weight change \>4.5 kg in last 6 months
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Change in fasting blood glucose | Baseline to Week 6 |
Secondary
| Measure | Time frame |
|---|---|
| Change in hip circumference | Baseline to Week 6 |
| Change in HDL cholesterol | Baseline to Week 6 |
| Change in HbA1c | Baseline to Week 6 |
Countries
Turkey (Türkiye)
Outcome results
None listed