ObesityNCT05545306
The Effects of Increasing Caloric Intake on Diet-Induced Thermogenesis and 24h Energy Expenditure
A study testing +200% of dietary requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat, fasting and -50% of energy balance requirements. 50% of calories from carbohydrates, 20% from protein, and 30% from fat in people with Obesity and Normal Physiology, run by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) at 1 site in United States.
Trial summary
Background: Diet-induced thermogenesis (DIT) is the amount of energy one's body uses to eat food, absorb the nutrients from the food, and process those nutrients. Researchers would like to understand more about how changing the balances of protein, fat, carbohydrates, and total calories in the diet can affect DIT. Read more about this study
- Who is it for?
- Ages 18 to 60 yearsHealthy volunteers can take part
- Conditions the study is for
- Obesity, Normal Physiology, Healthy Volunteers
- What is being tested?
- +200% of dietary requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat, fasting and -50% of energy balance requirements. 50% of calories from carbohydrates, 20% from protein, and 30% from fat
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 120 participants
- Where
- 1 siteUnited States
- Study dates
- 6 Jun 2023to 2 Feb 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 60 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- In order to be eligible to participate in this study, an individual must meet all of the following criteria:
- Male or female, aged 18-60 years old
- No episodes of intentional weight loss over previous 6 months
Who cannot join
- An individual who meets any of the following criteria will be excluded from participation in this study:
- Current use of tobacco products that exceed "Very Low Dependence" on the Fagerstrom Test for Nicotine Dependence Tool (score greater than 2)
- Diabetes
- Fasting glucose >= 126 mg/dl or hba1c >= 6.5% or
- history of type 1 or type 2 diabetes
- -Endocrine disorders, such as
Show all 40Show fewer
- History of Cushing s disease, pituitary disorders, or hypo- and hyperthyroidism
- TSH <0.1 or >= 10 uIU/mL
- Pulmonary disorders
- History of chronic obstructive pulmonary disease or other lung disease that which would limit ability to follow the protocol (investigator judgment)
- Cardiovascular diseases,
- Including history of coronary heart disease, heart failure, arrhythmias, and peripheral artery disease
- Hypertension,
- History of diagnosis and current treatment by an outside clinician
- or sitting blood pressure measurement, using an appropriate cuff, higher than
- 140/90 mmHg
- -Liver disease,
- including history of cirrhosis, active hepatitis B or C
- AST or ALT >=3 times upper limit of normal on screening labs
- Renal disease
- Serum creatinine >= 1.5 mg/dls
- Abnormal kidney function (eGFR <60 mL/min/1.73m^2)
- Central nervous system disease:
- including history of previous history of cerebrovascular accidents, dementia, and neurodegenerative disorders
- Cancer:
- History requiring treatment in the past five years, except for non-melanoma skin cancers or cancers that have clearly been cured or in the opinion of the investigator carry an excellent prognosis (e.g., Stage 1 cervical cancer).
- Infectious disease:
- History of active tuberculosis, HIV chronic coccidiomycosis or other chronic infections
- Conditions not specifically mentioned above may serve as criteria for exclusion at the discretion of the investigators
- Evidence of alcohol abuse as defined by > =8-point score on the Alcohol consumption screening AUDIT questionnaire in adults
- Current use of illegal drugs such as amphetamines, cocaine, opiates, or heroin; use of marijuana is permitted.
- For Females:
- i. Pregnancy or lactation by history and urine pregnancy test
- ii. Peri- or post-menopause by self-report or irregular menstrual cycle.
- Measured weight: greater than or equal to 450 lb. (maximum weight allowed on the DXA scanning tables by the manufacturer).
- Inability to speak or read English by self-report.
- Inability to provide informed consent
- History of psychological conditions including (but not limited to) claustrophobia, clinical depression, bipolar disorders, or forms of mental incapacity that would be incompatible with safe and successful participation in this study
- Current use of medications/dietary supplements/alternative therapies known to alter energy metabolism
- Inability to consume provided diets due to dietary concerns that will not allow them to consume >=95% of provided calories.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
NIDDK, Phoenix
Phoenix, Arizona, 85004
Office of Participant Recruitment-NIDDK, 602-200-5315, niddkphxcontact@mail.nih.gov
About this study
Background:
Diet-induced thermogenesis (DIT) is the amount of energy one's body uses to eat food, absorb the nutrients from the food, and process those nutrients. Researchers would like to understand more about how changing the balances of protein, fat, carbohydrates, and total calories in the diet can affect DIT.
Read more
Objective:
To learn how different diets can change a person's DIT.
Eligibility:
Healthy people aged 18 to 60 years who have not intentionally lost weight in the past 6 months.
Design:
Participants will stay in a clinic for about 35 days. They will eat only the food provided. They will receive 8 different diets during the study, including 7 test diets.
Participants will undergo multiple tests.
They will be screened with blood and urine tests and a test of their heart function.
During the first few days:
Their waist, thigh, and neck circumference will be measured.
They will have a DXA scan: They will lie on a padded table for about 20 minutes while an instrument measures the amount of fat in their body.
They will be tested for diabetes.
They will answer questionnaires about topics including eating behavior, hunger, and stress.
Throughout the study:
Their weight will be measured daily.
Blood tests will be repeated.
They will stay in a metabolic chamber a total of 9 times. They will remain in a closed room for 24 hours while researchers monitor the room temperature and levels of oxygen and carbon dioxide. Participants will collect all their urine for each 24-hour period.
...
Read the detailed description
Study Description:
Diet-Induced Thermogenesis (DIT) has been reported to increase as a function of the amount caloric intake. This study investigated this dose response between calorie intake and energy expenditure using a single liquid meal. By measuring EE over 24 hours in our respiratory chamber, we can capture the full extent of DIT at different caloric doses in relation to energy balance. Furthermore, we will investigate inter-individual differences in 24hEE response to different calorie loads. This is important as our previous studies demonstrated that individuals with greater EE during energy balance have 1) greater decrease in EE to fasting and 2) blunted EE response to higher calorie loads, in particular those with low protein content, respectively. Briefly, we will make multiple measurements of 24h EE in a whole-room indirect calorimeter, the gold standard measure of metabolism at multiple levels of energy intake relative to energy balance. These measures will be done at energy balance and in random order during fasting, 25, 50, 150 and 200% of energy balance requirements. Macronutrient balance for energy balance and lower calorie diets will be 50% carbohydrate, 30% fat, 20% protein; but for overfeeding will be 3% protein, 46% fat, 51% carbohydrate. The main goals of this research are to examine using state of the art measurement of DIT in a respiratory chamber whether there is indeed an association between caloric intake and energy expenditure and whether inter-individual response to calorie loads differs such that those with higher 24hEE during energy balance, have lower 24hEE during fasting and underfeeding 25 and 50% and lesser response to high calorie loads.
The primary goal of this study is to investigate the impact of relative calorie load on diet-induced thermogenesis.
Objectives:
Primary Objective:
- To determine whether an association exists between diet-induced thermogenesis, 24hEE and calorie load relative to energy balance.
Secondary Objectives:
- To determine if participants with higher energy balance 24hEE adjusted for body composition, age, and sex have lower adjusted 24hEE to lower calorie loads (fasting, 25 and 50% of energy needs)
- To determine if participants with higher energy balance 24h EE have lower adjusted 24hEE to high calorie loads with low protein overfeeding.
- To assess changes in hormones known to be associated with changes in 24hEE (e.g., FGF21, ghrelin)
- To assess changes in sympathetic nervous system activity based on changes in urinary catecholamines.
- To assess changes in substrate oxidation rates at various dietary loads.
Tertiary/Exploratory Objectives:
- To assess whether psychosocial differences are associated with 24hEE responses to calorie loads.
- Although our analytic plan and data collection procedure are meant to be all encompassing and comprehensive, our central exploratory, tertiary objective is to perform additional secondary data analyses in the future that answer additional research questions regarding diabetes and obesity risk that were not discussed in primary and secondary endpoints. These additional aims include, but are not limited to, associations of metabolic measures with psychosocial measures, hormonal endpoints, or future biomarker assayed at a later time point.
Endpoints:
Primary Endpoint:
- Diet induced thermogenesis, as calculated from 24h EE during feeding - 24h EE during fasting under different calorie loads
Secondary Endpoints:
- 24-hour energy expenditure during low calorie loads
- 24-hour energy expenditure at higher calorie loads with low protein calorie loads
- 24-hour energy expenditure during higher calorie loads with standard macronutrient mixed
- FGF-21, ghrelin, and other appetitive hormones
- Urinary catecholamines
- 24-hour respiratory quotient, protein, carbohydrate, and lipid oxidation.
Tertiary/Exploratory Endpoints:
- Psychosocial assessments, such as food insecurity and perceived stress
- Conditions
- Obesity, Normal Physiology, Healthy Volunteers
- Being tested
- +200% of dietary requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat, fasting, -50% of energy balance requirements. 50% of calories from carbohydrates, 20% from protein, and 30% from fat, +150% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat, +200% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from protein
- Keywords
- Weight Gain, Energy Expenditure, Low Protein Overfeeding, Fasting, Natural History
- Medical subject headings
- Obesity, Weight Gain, Fasting
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
+200% of dietary requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fatDietary supplement
+200% of energy balance requirements with standard macronutrient balance of 50% of calories from carbohydrates, 20% from protein, and 30% from fat
fastingDietary supplement
Fasting for at least 24 hours
-50% of energy balance requirements. 50% of calories from carbohydrates, 20% from protein, and 30% from fatDietary supplement
-50% of energy balance requirements with standard macronutrient balance of 50% of calories from carbohydrates, 20% from protein, and 30% from fat
+150% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fatDietary supplement
+150% of energy balance requirements with standard macronutrient balance of 50% of calories from carbohydrates, 20% from protein, and 30% from fat
+200% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from proteinDietary supplement
+200% of energy balance requirements with low protein macronutrient balance of 51% of the calories from carbohydrates, 46%, from fat and 3% from protein.
-25% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fatDietary supplement
-25% of energy balance (EB) requirements with standard macronutrient balance of 50% of calories from carbohydrates, 20% from protein, and 30% from fat
+150% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from proteinDietary supplement
+150% of energy balance requirements with low protein macronutrient balance of 51% of the calories from carbohydrates, 46%, from fat and 3% from protein.
| Study group | Role | What they receive |
|---|---|---|
| Set 1 | Active comparator | +150% LPF +150% SOF -50% +200% LPF +200% SOF Fasting -25% Receives: Dietary Supplement: +200% of dietary requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat; Dietary Supplement: fasting; Dietary Supplement: -50% of energy balance requirements. 50% of calories from carbohydrates, 20% from protein, and 30% from fat; Dietary Supplement: +150% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat; Dietary Supplement: +200% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from protein; Dietary Supplement: -25% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat; Dietary Supplement: +150% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from protein |
| Set 10 | Active comparator | +200% LPF -25% Fasting +200% SOF -50% +150% LPF +150% SOF Receives: Dietary Supplement: +200% of dietary requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat; Dietary Supplement: fasting; Dietary Supplement: -50% of energy balance requirements. 50% of calories from carbohydrates, 20% from protein, and 30% from fat; Dietary Supplement: +150% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat; Dietary Supplement: +200% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from protein; Dietary Supplement: -25% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat; Dietary Supplement: +150% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from protein |
| Set 2 | Active comparator | +150% LPF +200% LPF -50% +150% SOF Fasting -25% +200% SOF Receives: Dietary Supplement: +200% of dietary requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat; Dietary Supplement: fasting; Dietary Supplement: -50% of energy balance requirements. 50% of calories from carbohydrates, 20% from protein, and 30% from fat; Dietary Supplement: +150% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat; Dietary Supplement: +200% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from protein; Dietary Supplement: -25% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat; Dietary Supplement: +150% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from protein |
| Set 3 | Active comparator | +150% LPF Fasting +150% SOF -25% +200% SOF +200% LPF -50% Receives: Dietary Supplement: +200% of dietary requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat; Dietary Supplement: fasting; Dietary Supplement: -50% of energy balance requirements. 50% of calories from carbohydrates, 20% from protein, and 30% from fat; Dietary Supplement: +150% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat; Dietary Supplement: +200% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from protein; Dietary Supplement: -25% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat; Dietary Supplement: +150% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from protein |
| Set 4 | Active comparator | Fasting -25% +200% LPF -50% +200% SOF +150% SOF +150% LPF Receives: Dietary Supplement: +200% of dietary requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat; Dietary Supplement: fasting; Dietary Supplement: -50% of energy balance requirements. 50% of calories from carbohydrates, 20% from protein, and 30% from fat; Dietary Supplement: +150% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat; Dietary Supplement: +200% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from protein; Dietary Supplement: -25% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat; Dietary Supplement: +150% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from protein |
| Set 5 | Active comparator | -25% +150% SOF +200% LPF +150% LPF Fasting +200% SOF -50% Receives: Dietary Supplement: +200% of dietary requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat; Dietary Supplement: fasting; Dietary Supplement: -50% of energy balance requirements. 50% of calories from carbohydrates, 20% from protein, and 30% from fat; Dietary Supplement: +150% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat; Dietary Supplement: +200% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from protein; Dietary Supplement: -25% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat; Dietary Supplement: +150% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from protein |
| Set 6 | Active comparator | Fasting +200% LPF +200% SOF -50% +150% LPF -25% +150% SOF Receives: Dietary Supplement: +200% of dietary requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat; Dietary Supplement: fasting; Dietary Supplement: -50% of energy balance requirements. 50% of calories from carbohydrates, 20% from protein, and 30% from fat; Dietary Supplement: +150% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat; Dietary Supplement: +200% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from protein; Dietary Supplement: -25% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat; Dietary Supplement: +150% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from protein |
| Set 7 | Active comparator | -50% +200% SOF -25% +150% SOF Fasting +200% LPF +150% LPF Receives: Dietary Supplement: +200% of dietary requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat; Dietary Supplement: fasting; Dietary Supplement: -50% of energy balance requirements. 50% of calories from carbohydrates, 20% from protein, and 30% from fat; Dietary Supplement: +150% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat; Dietary Supplement: +200% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from protein; Dietary Supplement: -25% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat; Dietary Supplement: +150% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from protein |
| Set 8 | Active comparator | -50% +150% SOF +200% SOF +150% LPF -25% +200% LPF Fasting Receives: Dietary Supplement: +200% of dietary requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat; Dietary Supplement: fasting; Dietary Supplement: -50% of energy balance requirements. 50% of calories from carbohydrates, 20% from protein, and 30% from fat; Dietary Supplement: +150% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat; Dietary Supplement: +200% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from protein; Dietary Supplement: -25% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat; Dietary Supplement: +150% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from protein |
| Set 9 | Active comparator | +150% SOF -25% +150% LPF +200% SOF Fasting +200% LPF -50% Receives: Dietary Supplement: +200% of dietary requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat; Dietary Supplement: fasting; Dietary Supplement: -50% of energy balance requirements. 50% of calories from carbohydrates, 20% from protein, and 30% from fat; Dietary Supplement: +150% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat; Dietary Supplement: +200% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from protein; Dietary Supplement: -25% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat; Dietary Supplement: +150% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from protein |
What is being measured
The primary outcome is the main question the study is designed to answer.
Diet Induced Thermogenesis
DIT is calculated from 24h EE during feeding-24h EE during fasting under different caloric loads
Measured: 35 days
Secondary outcomes (6)
FGF 21
assessment of appetitive hormones before and after 24h in a whole room calorimeter with each intervention
Measured: 35 days
24 hour energy expenditure (24h EE)
24h EE is measured in a whole room calorimeter
Measured: 35 days
Substrate Oxidation
24h respiratory quotient measured in a whole room calorimeter
Measured: 35 days
Psychosocial Assessment
assessment of psychosocial state through assessment of food insecurity and perceived stress
Measured: 35 days
Ghrelin
assessment of appetitive hormones before and after 24h in a whole room calorimeter with each intervention
Measured: 35 days
Sympathetic nervous system activity
assessment of changes in urinary catecholamines with each intervention
Measured: 35 days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted19 Sep 2022
- Study start6 Jun 2023
- Primary completion2 Feb 2027 (estimated)
- Study completion2 Feb 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for ObesityStudies of the same condition, open and under way.
- More trials run by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)The sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Enrolment
- 120 participants (estimated)
Sponsor and investigators
- Sponsor type
- US National Institutes of Health
- Responsible party
- Sponsor
- Investigators
- Tomas Cabeza De Baca, Ph.D., Principal investigator, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05545306
- Sponsor's protocol ID
- 10000869
- Other IDs
- 000869-DK
- Status last verified
- 26 Aug 2026
- First submitted
- 16 Sep 2022
- Last updated
- 28 Aug 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Publications
Hollstein T, Ando T, Basolo A, Krakoff J, Votruba SB, Piaggi P. Metabolic response to fasting predicts weight gain during low-protein overfeeding in lean men: further evidence for spendthrift and thrifty metabolic phenotypes. Am J Clin Nutr. 2019 Sep 1;110(3):593-604. doi: 10.1093/ajcn/nqz062.
PubMed 31172178Li XY. [Clinical diagnosis of pulmonary solitary lesions: a correlative clinico-pathological review of 232 cases (author's transl)]. Zhonghua Jie He He Hu Xi Xi Ji Bing Za Zhi. 1981 Oct;4(5):285-7. No abstract available. Chinese.
PubMed 7341172
Study at a glance
From the registry record, last updated by the sponsor on 28 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effects of Increasing Caloric Intake on Diet-Induced Thermogenesis and 24h Energy Expenditure
- ClinicalTrials.gov ID
- NCT05545306
- Acronym / sponsor ID
- 10000869
- Conditions
- Obesity, Normal Physiology, Healthy Volunteers
- Keywords
- Weight Gain, Energy Expenditure, Low Protein Overfeeding, Fasting, Natural History
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 120 participants (estimated)
- Lead sponsor
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)US National Institutes of Health
- Study start
- 6 Jun 2023 (actual)
- Primary completion
- 2 Feb 2027 (estimated)
- Study completion
- 2 Feb 2027 (estimated)
- First posted
- 19 Sep 2022 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Background:
Diet-induced thermogenesis (DIT) is the amount of energy one's body uses to eat food, absorb the nutrients from the food, and process those nutrients. Researchers would like to understand more about how changing the balances of protein, fat, carbohydrates, and total calories in the diet can affect DIT.
Objective:
To learn how different diets can change a person's DIT.
Eligibility:
Healthy people aged 18 to 60 years who have not intentionally lost weight in the past 6 months.
Design:
Participants will stay in a clinic for about 35 days. They will eat only the food provided. They will receive 8 different diets during the study, including 7 test diets.
Participants will undergo multiple tests.
They will be screened with blood and urine tests and a test of their heart function.
During the first few days:
Their waist, thigh, and neck circumference will be measured.
They will have a DXA scan: They will lie on a padded table for about 20 minutes while an instrument measures the amount of fat in their body.
They will be tested for diabetes.
They will answer questionnaires about topics including eating behavior, hunger, and stress.
Throughout the study:
Their weight will be measured daily.
Blood tests will be repeated.
They will stay in a metabolic chamber a total of 9 times. They will remain in a closed room for 24 hours while researchers monitor the room temperature and levels of oxygen and carbon dioxide. Participants will collect all their urine for each 24-hour period.
...
Detailed description
Study Description:
Diet-Induced Thermogenesis (DIT) has been reported to increase as a function of the amount caloric intake. This study investigated this dose response between calorie intake and energy expenditure using a single liquid meal. By measuring EE over 24 hours in our respiratory chamber, we can capture the full extent of DIT at different caloric doses in relation to energy balance. Furthermore, we will investigate inter-individual differences in 24hEE response to different calorie loads. This is important as our previous studies demonstrated that individuals with greater EE during energy balance have 1) greater decrease in EE to fasting and 2) blunted EE response to higher calorie loads, in particular those with low protein content, respectively. Briefly, we will make multiple measurements of 24h EE in a whole-room indirect calorimeter, the gold standard measure of metabolism at multiple levels of energy intake relative to energy balance. These measures will be done at energy balance and in random order during fasting, 25, 50, 150 and 200% of energy balance requirements. Macronutrient balance for energy balance and lower calorie diets will be 50% carbohydrate, 30% fat, 20% protein; but for overfeeding will be 3% protein, 46% fat, 51% carbohydrate. The main goals of this research are to examine using state of the art measurement of DIT in a respiratory chamber whether there is indeed an association between caloric intake and energy expenditure and whether inter-individual response to calorie loads differs such that those with higher 24hEE during energy balance, have lower 24hEE during fasting and underfeeding 25 and 50% and lesser response to high calorie loads.
The primary goal of this study is to investigate the impact of relative calorie load on diet-induced thermogenesis.
Objectives:
Primary Objective:
- To determine whether an association exists between diet-induced thermogenesis, 24hEE and calorie load relative to energy balance.
Secondary Objectives:
- To determine if participants with higher energy balance 24hEE adjusted for body composition, age, and sex have lower adjusted 24hEE to lower calorie loads (fasting, 25 and 50% of energy needs)
- To determine if participants with higher energy balance 24h EE have lower adjusted 24hEE to high calorie loads with low protein overfeeding.
- To assess changes in hormones known to be associated with changes in 24hEE (e.g., FGF21, ghrelin)
- To assess changes in sympathetic nervous system activity based on changes in urinary catecholamines.
- To assess changes in substrate oxidation rates at various dietary loads.
Tertiary/Exploratory Objectives:
- To assess whether psychosocial differences are associated with 24hEE responses to calorie loads.
- Although our analytic plan and data collection procedure are meant to be all encompassing and comprehensive, our central exploratory, tertiary objective is to perform additional secondary data analyses in the future that answer additional research questions regarding diabetes and obesity risk that were not discussed in primary and secondary endpoints. These additional aims include, but are not limited to, associations of metabolic measures with psychosocial measures, hormonal endpoints, or future biomarker assayed at a later time point.
Endpoints:
Primary Endpoint:
- Diet induced thermogenesis, as calculated from 24h EE during feeding - 24h EE during fasting under different calorie loads
Secondary Endpoints:
- 24-hour energy expenditure during low calorie loads
- 24-hour energy expenditure at higher calorie loads with low protein calorie loads
- 24-hour energy expenditure during higher calorie loads with standard macronutrient mixed
- FGF-21, ghrelin, and other appetitive hormones
- Urinary catecholamines
- 24-hour respiratory quotient, protein, carbohydrate, and lipid oxidation.
Tertiary/Exploratory Endpoints:
- Psychosocial assessments, such as food insecurity and perceived stress
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 10
| Arm | Type | Receives |
|---|---|---|
| Set 1 | Active comparator | Dietary Supplement: +200% of dietary requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat, Dietary Supplement: fasting, Dietary Supplement: -50% of energy balance requirements. 50% of calories from carbohydrates, 20% from protein, and 30% from fat, Dietary Supplement: +150% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat, Dietary Supplement: +200% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from protein, Dietary Supplement: -25% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat, Dietary Supplement: +150% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from protein+150% LPF +150% SOF -50% +200% LPF +200% SOF Fasting -25% |
| Set 10 | Active comparator | Dietary Supplement: +200% of dietary requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat, Dietary Supplement: fasting, Dietary Supplement: -50% of energy balance requirements. 50% of calories from carbohydrates, 20% from protein, and 30% from fat, Dietary Supplement: +150% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat, Dietary Supplement: +200% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from protein, Dietary Supplement: -25% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat, Dietary Supplement: +150% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from protein+200% LPF -25% Fasting +200% SOF -50% +150% LPF +150% SOF |
| Set 2 | Active comparator | Dietary Supplement: +200% of dietary requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat, Dietary Supplement: fasting, Dietary Supplement: -50% of energy balance requirements. 50% of calories from carbohydrates, 20% from protein, and 30% from fat, Dietary Supplement: +150% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat, Dietary Supplement: +200% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from protein, Dietary Supplement: -25% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat, Dietary Supplement: +150% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from protein+150% LPF +200% LPF -50% +150% SOF Fasting -25% +200% SOF |
| Set 3 | Active comparator | Dietary Supplement: +200% of dietary requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat, Dietary Supplement: fasting, Dietary Supplement: -50% of energy balance requirements. 50% of calories from carbohydrates, 20% from protein, and 30% from fat, Dietary Supplement: +150% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat, Dietary Supplement: +200% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from protein, Dietary Supplement: -25% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat, Dietary Supplement: +150% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from protein+150% LPF Fasting +150% SOF -25% +200% SOF +200% LPF -50% |
| Set 4 | Active comparator | Dietary Supplement: +200% of dietary requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat, Dietary Supplement: fasting, Dietary Supplement: -50% of energy balance requirements. 50% of calories from carbohydrates, 20% from protein, and 30% from fat, Dietary Supplement: +150% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat, Dietary Supplement: +200% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from protein, Dietary Supplement: -25% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat, Dietary Supplement: +150% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from proteinFasting -25% +200% LPF -50% +200% SOF +150% SOF +150% LPF |
| Set 5 | Active comparator | Dietary Supplement: +200% of dietary requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat, Dietary Supplement: fasting, Dietary Supplement: -50% of energy balance requirements. 50% of calories from carbohydrates, 20% from protein, and 30% from fat, Dietary Supplement: +150% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat, Dietary Supplement: +200% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from protein, Dietary Supplement: -25% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat, Dietary Supplement: +150% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from protein-25% +150% SOF +200% LPF +150% LPF Fasting +200% SOF -50% |
| Set 6 | Active comparator | Dietary Supplement: +200% of dietary requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat, Dietary Supplement: fasting, Dietary Supplement: -50% of energy balance requirements. 50% of calories from carbohydrates, 20% from protein, and 30% from fat, Dietary Supplement: +150% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat, Dietary Supplement: +200% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from protein, Dietary Supplement: -25% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat, Dietary Supplement: +150% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from proteinFasting +200% LPF +200% SOF -50% +150% LPF -25% +150% SOF |
| Set 7 | Active comparator | Dietary Supplement: +200% of dietary requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat, Dietary Supplement: fasting, Dietary Supplement: -50% of energy balance requirements. 50% of calories from carbohydrates, 20% from protein, and 30% from fat, Dietary Supplement: +150% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat, Dietary Supplement: +200% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from protein, Dietary Supplement: -25% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat, Dietary Supplement: +150% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from protein-50% +200% SOF -25% +150% SOF Fasting +200% LPF +150% LPF |
| Set 8 | Active comparator | Dietary Supplement: +200% of dietary requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat, Dietary Supplement: fasting, Dietary Supplement: -50% of energy balance requirements. 50% of calories from carbohydrates, 20% from protein, and 30% from fat, Dietary Supplement: +150% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat, Dietary Supplement: +200% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from protein, Dietary Supplement: -25% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat, Dietary Supplement: +150% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from protein-50% +150% SOF +200% SOF +150% LPF -25% +200% LPF Fasting |
| Set 9 | Active comparator | Dietary Supplement: +200% of dietary requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat, Dietary Supplement: fasting, Dietary Supplement: -50% of energy balance requirements. 50% of calories from carbohydrates, 20% from protein, and 30% from fat, Dietary Supplement: +150% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat, Dietary Supplement: +200% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from protein, Dietary Supplement: -25% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat, Dietary Supplement: +150% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from protein+150% SOF -25% +150% LPF +200% SOF Fasting +200% LPF -50% |
Who may qualify
- Ages
- 18 to 60 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (3 listed)
- In order to be eligible to participate in this study, an individual must meet all of the following criteria:
- Male or female, aged 18-60 years old
- No episodes of intentional weight loss over previous 6 months
Key exclusion criteria (40 listed)
- An individual who meets any of the following criteria will be excluded from participation in this study:
- Current use of tobacco products that exceed "Very Low Dependence" on the Fagerstrom Test for Nicotine Dependence Tool (score greater than 2)
- Diabetes
- history of type 1 or type 2 diabetes
- -Endocrine disorders, such as
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| +200% of dietary requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat+200% of energy balance requirements with standard macronutrient balance of 50% of calories from carbohydrates, 20% from protein, and 30% from fat | Dietary supplement | Set 1, Set 10, Set 2, Set 3, Set 4, Set 5, Set 6, Set 7, Set 8, Set 9 |
| fastingFasting for at least 24 hours | Dietary supplement | Set 1, Set 10, Set 2, Set 3, Set 4, Set 5, Set 6, Set 7, Set 8, Set 9 |
| -50% of energy balance requirements. 50% of calories from carbohydrates, 20% from protein, and 30% from fat-50% of energy balance requirements with standard macronutrient balance of 50% of calories from carbohydrates, 20% from protein, and 30% from fat | Dietary supplement | Set 1, Set 10, Set 2, Set 3, Set 4, Set 5, Set 6, Set 7, Set 8, Set 9 |
| +150% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat+150% of energy balance requirements with standard macronutrient balance of 50% of calories from carbohydrates, 20% from protein, and 30% from fat | Dietary supplement | Set 1, Set 10, Set 2, Set 3, Set 4, Set 5, Set 6, Set 7, Set 8, Set 9 |
| +200% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from protein+200% of energy balance requirements with low protein macronutrient balance of 51% of the calories from carbohydrates, 46%, from fat and 3% from protein. | Dietary supplement | Set 1, Set 10, Set 2, Set 3, Set 4, Set 5, Set 6, Set 7, Set 8, Set 9 |
| -25% of energy balance requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat-25% of energy balance (EB) requirements with standard macronutrient balance of 50% of calories from carbohydrates, 20% from protein, and 30% from fat | Dietary supplement | Set 1, Set 10, Set 2, Set 3, Set 4, Set 5, Set 6, Set 7, Set 8, Set 9 |
| +150% of dietary requirements, 51% of the calories from carbohydrates, 46%, from fat and 3% from protein+150% of energy balance requirements with low protein macronutrient balance of 51% of the calories from carbohydrates, 46%, from fat and 3% from protein. | Dietary supplement | Set 1, Set 10, Set 2, Set 3, Set 4, Set 5, Set 6, Set 7, Set 8, Set 9 |
Primary outcome
Diet Induced Thermogenesis
Time frame: 35 days
DIT is calculated from 24h EE during feeding-24h EE during fasting under different caloric loads
6 secondary outcomes
FGF 21
Time frame: 35 days
24 hour energy expenditure (24h EE)
Time frame: 35 days
Substrate Oxidation
Time frame: 35 days
Psychosocial Assessment
Time frame: 35 days
Ghrelin
Time frame: 35 days
Sympathetic nervous system activity
Time frame: 35 days
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 28 Aug 2026.
- Background: PubMed 31172178Hollstein T, Ando T, Basolo A, Krakoff J, Votruba SB, Piaggi P. Metabolic response to fasting predicts weight gain during low-protein overfeeding in lean men: further evidence for spendthrift and thrifty metabolic phenotypes. Am J Clin Nutr. 2019 Sep 1;110(3):593-604. doi: 10.1093/ajcn/nqz062.
- Background: PubMed 7341172Li XY. [Clinical diagnosis of pulmonary solitary lesions: a correlative clinico-pathological review of 232 cases (author's transl)]. Zhonghua Jie He He Hu Xi Xi Ji Bing Za Zhi. 1981 Oct;4(5):285-7. No abstract available. Chinese.
- NIH Clinical Center Detailed Web PageLink provided by the sponsor.
- Individual participant dataSharing planned: Undecided
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Tomas Cabeza De Baca, Ph.D. principal investigator
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing +200% of dietary requirements, 50% of calories from carbohydrates, 20% from protein, and 30% from fat, fasting and -50% of energy balance requirements. 50% of calories from carbohydrates, 20% from protein, and 30% from fat in people with Obesity and Normal Physiology, run by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 40 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 28 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Office of Participant Recruitment (NIDDK ((602) 200-5315, niddkphxcontact@mail.nih.gov), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Diet Induced Thermogenesis (time frame: 35 days). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT05545306, which also lists 2 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 28 Aug 2026.