An interventional study of MT1 and MT2 in Obesity, Meal Frequency and Appetite, sponsored by University of Aberdeen. Completed at 1 site in United Kingdom. Open to participants aged 18 Years to 65 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-09-04.
Sponsored by University of Aberdeen · Not applicable, Interventional, and Health services research
Obesity is one of the largest worldwide health problems. There are increasing rates of overweight and obesity, and in recent years, worldwide the percentage of overweight and obesity among adults now exceeds 1.9 billion and 650 million, respectively. Overweight and obesity are associated with an increase risk of type 2 diabetes (T2D), coronary heart disease, hypertension and other non-communicable diseases. There are multiple nutritional causes for obesity, including both the type and amount of food consumed. Other non-nutritional factors can be just as important to influence body mass, such as the number of meals eaten, which is termed meal frequency. The changing food environment influences calorie consumption, such as increased food variety, increased availability and food processing, a nocturnal lifestyle that disrupts the circadian clock, meal timing and frequency, irregular meal patterns, and prolonged duration of eating during the day. This results in increased food and beverage consumption throughout the day. Meal frequency is commonly defined as, 'the number of foods or drinks a person consumes in one day. Meals and snacks are less clearly defined. Meal is defined as any food providing≥ 50 kcal and separated by more than one hour. In most cultures, the name meal is given to the three eating episodes in a day: breakfast, lunch, and dinner; or breakfast, brunch, lunch, supper, and dinner. In this study, the investigators will use the definition of "breakfast, brunch, lunch, supper, and dinner", but it will be on restricted time: 10 hours eating and 14 hours fasting (from 7:00 to 17:00) and one type of diet (high protein diet). Other researchers have defined meals by the time of the day, such as early and late breakfast, lunch and dinner intake. These definitions differ according to culture. Other researchers have defined meals based on timing, such as (6:00 am -10:00 am), (12:00 pm - 3:00 pm), and (6:00 pm - 9:00 pm). Some studies have highlighted that there are factors that affect the number of meals which a person consumes. Eating a high amount of energy during breakfast helps to feel full for a longer period. Time of eating and duration of eating or not eating. The type of macronutrient intake; for example, high protein (HP) intake reduces ad libitum energy intake. The number of meals eaten per day; some studies have confirmed that consuming small frequent meals is better for healthy weight and appetite control in the general population, compared to consuming one huge meal a day. This can assist control of appetite and plasma glucose concentrations. On the other hand, recent research has indicated that consuming (≥6 meals/day) increases disease risk significantly more than consuming (1-2 meals/day). Some researchers believe that there is no relationship between meal frequency and body weight.
Number of Participants:
10 adults (males and females) who have expressed an interest in taking part and meet the inclusion criteria. Should there be any withdrawals, the investigators will continue to replace participants until 10 have completed the trial.
The primary objective of this study was to explore the efficacy and physiological responses to a controlled time-restricted eating regime and dietary interventions (2 or 5 meals per day) on the participant's appetite response, measured with visual analogue scales (VAS). VAS is completed on test days (recorded at time points 0, 30, 60, 90, 120, 150 and 180 minutes) and on all other study days (recorded hourly during waking hours). The secondary objective is to compare the influence of dietary interventions (2 or 5 meals per day) on the following: plasma fasting blood glucose and 3 hours post-prandially after a standardized test meal. Analysed by KONE for timepoints 0 and 180 mins. Plasma fasting insulin and 3 hours post-prandially after a standardized test meal. Analysed by ELISA for timepoints 0 and 180 mins. Continuous glucose monitoring System (CGMS) on all study days to assess free-living glycaemic control in response to diet. All components of energy expenditure and substrate utilization are monitored by ventilated hood (indirect calorimetry) as resting metabolic rate (RMR, 30 minutes before eating breakfast); thermic effect of food (TEF postprandial 3 hours, measured 10 minutes every 30 minutes by the ventilated hood). Moreover, to assess changes in physical activity, with accelerometry on all study days and the Baecke Physical Activity Questionnaire (BPAQ) completed on each test day. To assess if meal frequency influences sleep, a sleep diary will be completed on all study days and the Epworth Sleepiness questionnaire (ESQ) completed on each test day. Finally, to assess if meal frequency influences body mass and body composition (fasted body weight measured on all food collection and test days), and fasted waist and hip circumferences and fat mass by bio-impedance analysis (BIA) measured on all test days.
A randomized crossover trial (RCT). Each participant will complete a 21 day study design as follows:
Study Diets:
During the screening visit, RMR was measured for each participant, and based on the results, each participant received a different meal portion. After receiving the RMR results for each participant, the kitchen staff at the Human Intervention Studies Unit (HISU) were emailed the participant number, RMR results, and the randomised diet they would start (2MPD or 5MPD), allowing the dietitian to assign the closest diet on the diet scales (1250, 1500, 1750, 2000, 2250 kcal). For example, if the RMR result for a volunteer were 1800 kcal, it would be put in the closest diet, 1750 kcal.
All food will be prepared at the Human Intervention Studies Unit (HISU), Rowett Institute.
This study will include two types of diet:
Study Measurements:
In total there will be nine study visits to the Human Intervention Studies Unit (HISU), Rowett Institute: one screening visit, which last approximately 2 hours, 4 visits for Test Days representing pre and post dietary phases (day 3rd, 7th, 17th, and 21st), which last approximately 4-5 hours, and 6 visits to collect food (day 1st, 3rd, 6th, 15th, 17th, and 20th), two of them are at the same day of Test Day, which last approximately 30 mins, except 2 visits will be 4-5 hours because it is the day of Test Days too. All visits details are described in the protocol. Researcher(s) carrying out the procedure: The study will be co-ordinated by a Research Team, consisting of Professor Alexandra Johnstone (PI), Prof Justin Rochford (CI), Ms Nouf Alkhattabi (PhD student), Claire Fyfe (Research Technician), David Bremner (Research Assistant), Claire Kidd (Research Assistant), Christina Petkov (Honorary Research Nurse).
Screening Visit:
The participant should already have a copy of the PIS in advance of the consent and screening visit should already have a good understanding of the study and have sufficient time to read it before this visit. After discussion, the consent should always be obtained before the health status and eligibility. n=10 to complete.
All measurements will be conducted after a fast from 10:00 pm the night before. Breakfast will be provided at the end of the screening visit.
Screening will continue until study completion and involves.
The participants will then be given a 7-day weighed intake food diary and scales to take away with them to complete to establish their regular eating habits before the start of diet provision.
Test Day Visits (on Days 3, 7, 17 and 21):
All measurements will be conducted after a fast from 10pm the night before. On days 3 and 17 meals will be provided as breakfast, lunch, dinner, and snacks according to the intervention diet randomisation (2MPD or 5MPD), while on days 7 and 21 only breakfast will be provided.
Overnight fasted anthropometric measures
Venepuncture for fasted blood sampling (one 4ml LiHep tube):
The total volume of blood taken will be as follows:
The total blood taken for 4 visits will be 32ml for each participant.
Post-prandial measurement of participant appetite by VAS at T30, T60, T90, T120, T150 and T180mins.
T180mins LiHep Spare (2x300μl plasma in 1.5ml Eppendorf).
Other Measurements:
11,522 studies on the registry are indexed under Obesity; 2,033 are open to participants now.
This study's enrollment of 12 is below the median of 67 across 9,006 interventional studies indexed under Obesity.
Browse Obesity studies →University of Aberdeen is the lead sponsor of 176 studies on the registry; 24 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Intervention weight loss diet 1 (2MPD, 2 meals/day) for 4 days
Other: MT1 · Other: MT2
Intervention weight loss diet 2 (5MPD, 5 meals/day) for 4 days
Other: MT1 · Other: MT2
\- On days 1-2 (MT1) 15:30:55% of energy from protein, fat and carbohydrate respectively).
\- On days 16-17 (MT2) 15:30:55% of energy from protein, fat and carbohydrate respectively).
The participant's appetite response on the test day (day 3rd, 7th, 17th, and 21st)
Measured with visual analogue scales (VAS).
Time frame: On test days recorded at timepoints 0, 30, 60, 90, 120, 150 and 180 minutes. On all study days recorded hourly during waking hours. The straight line is 100 mm long, left side indicates low symptoms.
Plasma blood glucose on the test day (day 3rd, 7th, 17th, and 21st)
The plasma fasting blood glucose and 180 minutes post-prandially after a standardized test meal which is analysed by KONE system.
Time frame: The blood samples will be collected by multiple venepuncture before breakfast (T0 minutes) and post prandial (T180 minutes).
Plasma blood insulin on the test day (day 3rd, 7th, 17th, and 21st)
Plasma fasting blood insulin (T0 minutes) and (T180 minutes) post-prandially after a standardized test meal which analysed by ELISA.
Time frame: The blood samples will be collected by multiple venepuncture before breakfast (T0 minutes) and post prandial (T180 minutes).
Continuous glucose monitoring System (CGMS)
The device measures the glucose levels during day over 7 days when it is worn and will enable us to determine the volunteer body's responses to the meals. Two CGMS sensors will be fitted during the study: * on the 1st day of the study (removed on study day 7). * on the 15th day of the study (removed on study day 21).
Time frame: Day 1-7 and day 15-21 which correspond to weight loss diet periods.
Resting Metabolic Rate (RMR) on test day (day 3rd, 7th, 17th, and 21st)
All components of energy expenditure and substrate utilization are monitored by ventilated hood (indirect calorimetry).
Time frame: Resting metabolic rate (RMR, 30 minutes before eating breakfast) on screening visit and Test Day (3, 7, 17, and 21).
Thermic Effect of Food (TEF ) on test day (day 3rd, 7th, 17th, and 21st)
All components of energy expenditure and substrate utilization are monitored by ventilated hood (indirect calorimetry).
Time frame: Thermic effect of food (TEF post prandial 180 minutes, measured 10 minutes, every 30 minutes by ventilated hood; at 30, 60, 90, 10, 150, and 180 minutes) on Test Day 3, 7, 17, and 21.
Physical activity (Actigraphy)
To assess changes in physical activity with the accelerometery (Actigraphy).
Time frame: - accelerometery (Actigraphy) on all study days, measured on days 1-7 and days 15-21).
Physical activity (BPAQ)
To assess changes in physical activity with the Baecke Physical Activity Questionnaire (BPAQ).
Time frame: - the Baecke Physical Activity Questionnaire (BPAQ) completed tow times, on Day 3, 7, 17, and 21.
Sleep (Actigraphy)
To assess if meal frequency influences sleep using Actigraphy monitor.
Time frame: Actigraphy worn on all study days (day 1-7 and day 15-21).
Sleep
To assess if meal frequency influences sleep using a sleep diary
Time frame: A sleep diary completed on all study days (Day 1-7 and day 15-21).
Sleep (ESQ)
To assess if meal frequency influences sleep using the Epworth Sleepiness questionnaire (ESQ)
Time frame: The Epworth Sleepiness questionnaire (ESQ) on all test days (Day 3, 7, 17, and 21).
Body Weight
Our study for measured the body weight used the OHAUS CD-11 scale to the nearest 0.1 kg.
Time frame: Fasted body weight measured on all food collection (Day 1, 3, 6, 15, 17, and 20) and test days (Day 3, 7, 17, and 21).
Hight
The investigators used the Stadiometer (Seca 213) to the nearest 0.1 cm for height measurement.
Time frame: Hight measured once only at screening visit to calculate BMI.
Body Composition
To measure the fat mass (kg) and fat-free (kg) mass by bio-impedance analysis (BIA)
Time frame: BIA measure on test day (Day 3, 7, 17, and 21).
Waist and Hip Circumference
To assess waist and hip circumferences change measured using a tape measure, recorded in mm.
Time frame: On test day (Day 3, 7, 17, and 21).
PDFs hosted by the registry, ClinicalTrials.gov.
Plan to share: Undecided
Ran from Sep 2024 to primary completion in Apr 2025, 7 months.
Of 3,680 non-industry interventional studies with no phase under Obesity, half reached primary completion within 23 months of starting (the median), counting those still running; a quarter within 10 and three quarters within 43. This study's 7 months is below that.
Counting every sponsor, half of 3,843 studies reached it within 22 months; a quarter within 10 and three quarters within 42.
How these figures are worked out, and which studies are left out of them.
This study is completed, as verified in Feb 2025. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.