An interventional study of DGA Mediterranean diet pattern, energy balance and DGA Mediterranean diet pattern, negative energy balance in Obesity and Body Weight, sponsored by USDA, Western Human Nutrition Research Center. Completed at 1 site in United States. Open to female participants aged 19 Years to 64 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-09-09.
Sponsored by USDA, Western Human Nutrition Research Center · Not applicable, Interventional, and Basic science
This study, at the Western Human Nutrition Research Center (WHNRC), will focus on whether or not achieving and maintaining a healthy body weight is the most important health promoting recommendation of the Dietary Guidelines for Americans (DGA).The investigators hypothesize that improvement in cardiometabolic risk factors resulting from eating a DGA style diet will be greater in people whose energy intake is restricted to result in weight loss compared to those who maintain their weight. The investigators further propose that during a state of energy restriction, a higher nutrient quality diet such as the DGA style diet pattern, will result in greater improvement in cardiometabolic risk factors compared to a typical American diet (TAD) pattern that tends to be lower nutrient quality (more energy-dense and less nutrient-rich.)
This will be a 28-week study including pre-diet testing (week 1), an 8-week controlled feeding period, post-diet testing (week 10), a follow-up period of dietary education and observation, and end of study testing (week 28). During the 8 week feeding, participants will be randomly assigned one of the following diets:
In the follow-up phase, the investigators will evaluate how multiple factors may influence body weight management, including previous dietary exposure, as well as the role of cognitive function, executive function, genetics, habitual diet, physical activity, eating behavior, stress and stress responsivity, metabolic flexibility and gut microbiome.
11,522 studies on the registry are indexed under Obesity; 2,033 are open to participants now.
This study's enrollment of 54 is below the median of 67 across 9,006 interventional studies indexed under Obesity.
Browse Obesity studies →USDA, Western Human Nutrition Research Center is the lead sponsor of 54 studies on the registry; 1 is 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.
A blood test of average blood sugar over the past two to three months, given as a percentage or in mmol/mol. 6.5% (48 mmol/mol) or more is the usual threshold for diabetes, normally confirmed by a second test.
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
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.
HbA1c
A blood test of average blood sugar over the past two to three months, given as a percentage or in mmol/mol. 6.5% (48 mmol/mol) or more is the usual threshold for diabetes, normally confirmed by a second test.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hemoglobin (Hb)
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Diet plan focused on energy balance (meets calorie needs), emphasizes fruits, vegetables and whole grains and limits calories from added sugars and saturated fats and reduces sodium intake per Dietary Guidelines for Americans (DGA) recommendations.
Other: DGA Mediterranean diet pattern, energy balance
Negative energy balance (\~25% calorie reduction compared to needs), emphasizes fruits, vegetables and whole grains and limits calories from added sugars and saturated fats and reduces sodium intake per Dietary Guidelines for Americans (DGA) recommendations.
Other: DGA Mediterranean diet pattern, negative energy balance
Typical American Diet (TAD) with negative energy balance (\~25% calorie reduction compared to needs) which mimics intake of fruits, vegetables, whole grains, added sugars, saturated fats and sodium based on data from What We Eat in America (WWEIA).
Other: TAD diet pattern, negative energy balance
Foods and beverages will be provided for participants for eight weeks. During the controlled feeding portion of the study the DGA Mediterranean diet pattern will be based on the Table A7-1 of the 2015 Dietary Guidelines for Americans which outlines daily nutritional goals for age-sex groups based on Dietary Reference Intakes (DRI) and dietary guidelines recommendations.
Foods and beverages will be provided for participants for eight weeks. During the controlled feeding portion of the study the DGA Mediterranean diet pattern will be based on the Table A7-1 of the 2015 Dietary Guidelines for Americans which outlines daily nutritional goals for age-sex groups based on Dietary Reference Intakes (DRI) and dietary guidelines recommendations
Foods and beverages will be provided for participants for eight weeks. During the controlled feeding portion of the study the be based on evidence collected from What We Eat in America (WWEIA) data. Based on this data the participants will be provided a diet that reflects American dietary trends.
Change in body weight
Body weight will be measured to the nearest 0.1 kg using a calibrated electronic scale.
Time frame: Measured weekly for weeks 1 through 10, and weeks 13, 17, 21, 24 and 28
Height
Height will be measured to the nearest 0.1 cm using a wall-mounted stadiometer.
Time frame: Week 1
Change in body mass index
Body weight and height will be used to calculate Body Mass Index (BMI) as kg/m2.
Time frame: Measured weekly for weeks 1 through 10, and weeks 13, 17, 21, 24 and 28
Change in body water (via InBody)
Measured using bioelectrical impedance analysis (BIA) with an InBody 770® expressed as kg.
Time frame: Week 1, 10, 28
Change in body fat (via DEXA scan)
Fat mass (grams) will be measured using dual energy x-ray absorptiometry (DEXA).
Time frame: Week 1, 10, 28
Change in waist circumference
Waist circumference is measured with an anthropometric tape. Measurements will be performed in duplicate and averages recorded to the nearest 0.1 cm.
Time frame: Week 1, 10, 28
Change in hip circumference
Hip circumference is measured with an anthropometric tape. Measurements will be performed in duplicate and averages recorded to the nearest 0.1 cm.
Time frame: Week 1, 10, 28
Change in waist to hip ratio
Waist and hip circumference will be expressed as a ratio.
Time frame: Week 1, 10, 28
Change in resting systolic blood pressure
Blood pressure will obtained via automated instrument and blood pressure cuff. At least two measurements will be made, expressed in mmHg, and the average value will be recorded.
Time frame: Week 1, 10, 28
Change in resting diastolic blood pressure
Blood pressure will obtained via automated instrument and blood pressure cuff. At least two measurements will be made, expressed in mmHg, and the average value will be recorded.
Time frame: Week 1, 10, 28
Change in resting heart rate
Resting heart rate (pulse) will obtained via automated instrument in beats per minute.
Time frame: Week 1, 10, 28
Genetic Risk of Obesity
Genomic DNA will be collected from white blood cells. A polygenic risk score (PRS) indexing genetic predisposition to obesity using known obesity single nucleotide polymorphisms (SNPs).
Time frame: Week 1
Change in vascular health
Peripheral Arterial Tone (PAT) technology will be used to measure vascular health. The EndoPAT test is a non-invasive measurement of the overall health of the endothelium.
Time frame: Week 1, 5, 10
Change in liver fat
Liver fat assessed from the Controlled Attenuation Parameter (CAP) computed from the liver stiffness measurement using the Fibroscan®
Time frame: Week 1 and 10
Change in liver stiffness
Liver stiffness assessed from the shear wave speed with pulse echo ultrasound using the Fibroscan®
Time frame: Week 1 and 10
Change in blood metabolite profiles
Analysis of metabolites, the small molecule substrates, intermediates and products of metabolism analyzed by mass spectrometry (MS). Includes branched chain amino acids, 2 hydroxybutyric acid, acylcarnitines, saturated, monounsaturated and polyunsaturated non-esterified fatty acids, triglyceride species, phospholipid species, bile acids and steroid hormones.
Time frame: Week 1 and 10
Change in fasting blood glucose
This outcome will evaluate blood sugars levels in the fasted state.
Time frame: Week 1, 10, 28
Change in hemoglobin A1C
This outcome will evaluate glycated hemoglobin as a reflection of the plasma glucose level during the past two to three months.
Time frame: Week 1, 10, 28
Change in urinary sodium
Urinary sodium will be measured as indicators of dietary compliance during the feeding intervention of the study. All urine passed for a 24 hour period will be collected.
Time frame: Week 1, 5, 7 and 10
Change in urinary potassium
Urinary potassium will be measured as indicators of dietary compliance during the feeding intervention of the study. All urine passed for a 24 hour period will be collected.
Time frame: Week 1, 5, 7 and 10
Change in urinary nitrogen
Urinary nitrogen will be measured as indicators of dietary compliance during the feeding intervention of the study. All urine passed for a 24 hour period will be collected.
Time frame: Week 1, 5, 7 and 10
Change in red blood cell fatty acids
Red blood cell fatty acids will be analyzed by mass spectrometry (MS).
Time frame: Week 1, 10, 28
Change in C-reactive protein
C-Reactive Protein will be measured as a non-specific marker for inflammation.
Time frame: Week 1, 10, 28
Change in carotenoid levels
Serum carotenoids, including vitamin A, alpha-carotene, and beta-carotene will be used to evaluate nutrient status and dietary intake of vegetables prior to feeding intervention and post feeding intervention.
Time frame: Week 1 and 10
Change in total cholesterol
Total cholesterol will be collected to evaluate cardiac risk expressed as milligrams per deciliter (mg/dL).
Time frame: Week 1 and 10
Change in high density lipoprotein (HDL) cholesterol
HDL cholesterol will be collected to evaluate cardiac risk expressed as milligrams per deciliter (mg/dL).
Time frame: Week 1 and 10
Change in low density lipoprotein (LDL) cholesterol
LDL cholesterol will be collected to evaluate cardiac risk expressed as milligrams per deciliter (mg/dL).
Time frame: Week 1 and 10
Change in triglycerides in response to a meal
Triglycerides will be measured in blood (mg/dL).
Time frame: Baseline and 1, 2, 3, and 6 hours after a challenge meal
Change in ghrelin in response to a meal
Ghrelin will be evaluated as an indicator of hunger signaling.
Time frame: Baseline and 1, 2, 3, and 6 hours after a challenge meal
Change in leptin in response to a meal
Leptin will be evaluated as an indicator of satiety signaling.
Time frame: Baseline and 1, 2, 3, and 6 hours after a challenge meal
Change in insulin in response to a meal
Insulin measured in blood using an antibody based assay. Will also be expressed as the quantitative insulin sensitivity check index (QUICKI).
Time frame: Baseline and 1, 2, 3, and 6 hours after a challenge meal
Change in Matsuda Index
Matsuda index will be calculated from plasma glucose and insulin.
Time frame: Baseline and 1, 2 hours after a challenge meal
Change in resting metabolic rate
Respiratory gas exchange measurements (oxygen consumption-VO2 and carbon dioxide production-VCO2) will be made to determine metabolic rate using a metabolic cart system.
Time frame: Week 1 and 10
Change in post-prandial metabolic rate
Post-prandial metabolic rate measured using indirect calorimetry.
Time frame: 1, 2, 3 and 6 hours after a meal
Change in metabolic flexibility
The formula is designed to deliver approximately 800 kcals total with 60% kcals from fat (approximately 55 g of fat), 25% kcals from carbohydrates, and 15% of kcals from protein.
Time frame: Week 1 and 10
Change in predicted VO2 max
Cardiorespiratory endurance will be evaluated by measuring heart rate (HR) and oxygen consumption (VO2) during a walking graded exercise test on a treadmill.
Time frame: Week 1, 10, 28
Change in interstitial glucose levels
A continuous glucose monitor (CGM) will be used to continuously assess interstitial glucose levels. The Abbott Freestyle Libre Pro Sensor is inserted under the skin on the back of the arm. The sensor will measure the interstitial glucose level every fifteen minutes. Participants will wear the monitors for fourteen days.
Time frame: Week 1 and 10
Change in executive function
Assessed using Cambridge Gambling Task (CGT), from Cambridge Neuropsychological Test Automated Battery (CANTAB).
Time frame: Week 1 and 10
Change in response speed
Assessed using Motor Screening Task (MOT), from Cambridge Neuropsychological Test Automated Battery (CANTAB).
Time frame: Week 1 and 10
Change in verbal memory
Assessed using Verbal Recognition Memory (VRM) task from Cambridge Neuropsychological Test Automated Battery (CANTAB).
Time frame: Week 1 and 10
Change in psycho-motor speed
Assessed using Reaction Time (RTI) task from Cambridge Neuropsychological Test Automated Battery (CANTAB).
Time frame: Week 1 and 10
Change in spatial memory
Assessed using Spatial Working Memory (SWM) task from Cambridge Neuropsychological Test Automated Battery (CANTAB).
Time frame: Week 1 and 10
Change in multitasking
Assessed using Multitasking Test (MTT) from Cambridge Neuropsychological Test Automated Battery (CANTAB).
Time frame: Week 1 and 10
Change in social cognition
Assessed using Emotional Recognition (ERT) task from Cambridge Neuropsychological Test Automated Battery (CANTAB).
Time frame: Week 1 and 10
Change in attentive function
Assessed using Stop Signal Task (STT) from Cambridge Neuropsychological Test Automated Battery (CANTAB).
Time frame: Week 1 and 10
Change in allostatic load
Allostatic load (AL) is an aggregate value derived from several parameters that assess physiologic adaptive response to neural or neuroendocrine stressors. The following measures are used to determine the AL score: Urinary cortisol and catecholamine levels, resting blood pressure, waist to hip ratio, blood levels of high sensitivity C-Reactive Protein, cholesterol, dehydroepiandrosterone sulfate and hemoglobin A1c, and urinary levels of epinephrine and norepinephrine.
Time frame: Week 1, 10, 28
Change in continuous systolic blood pressure
Blood pressure measured using a Continuous Non-invasive Arterial Pressure (CNAP®) device in mmHg.
Time frame: Week 1 and 10
Change in continuous diastolic blood pressure
Blood pressure measured using a Continuous Non-invasive Arterial Pressure (CNAP®) device in mmHg.
Time frame: Week 1 and 10
Change in mean arterial blood pressure
Blood pressure measured using a Continuous Non-invasive Arterial Pressure (CNAP®) device in mmHg .
Time frame: Week 1 and 10
Change in mood
Mood assessed using the Profile of Mood States (POMS). Total Mood Disturbance (TMD) score is found from the difference between "negative" subscales - "positive" subscales. Individual scores on the POMS range from -32 to 200 with higher scores indicating higher mood disturbance.
Time frame: Week 1 and 10
Change in perceived stress
Perceived stress measured using the Perceived stress scale (PSS). Scores on the PSS can range from 0 to 40 with higher scores indicating higher perceived stress. Responses for individual questions are summed to a total score.
Time frame: Week 1, 6, 10, 19 and 28
Change in self-efficacy
This 20 item questionnaire is a measurement of the capacity to execute behaviors necessary to change their weight and begin to implement exercise in their lives regularly.
Time frame: Week 10, 19 and 28
Change in diet satisfaction
This 28 item questionnaire acts as a valid instrument for assessing diet satisfaction in the context of weight-management. This measurement assesses diet satisfaction both within and outside the context of weight-loss treatment, as well as to assesses change in satisfaction as a result of treatment.
Time frame: Week 1, 19 and 28
Change in appetite
A computer tablet with stylus will be used to assess hunger and appetite, defined as perceived hunger, fullness, desire to eat, prospective consumption and other measures of food craving and perceived hypoglycemia. Questions will be presented one-by-one on the screen and participants will be asked to express their response using visual analog scales (VAS). This measurement will be evaluated during the meal challenge assessment.
Time frame: Week 1 and 10
Three factor eating questionnaire
This 18 item questionnaire is used to examine three dimensions of human eating behavior including cognitive restraint, disinhibition or uncontrolled eating and hunger.
Time frame: Week 1 and 10
Barriers to physical activity
Participants will be asked to complete the Barriers to Being Active questionnaire.
Time frame: Week 1
Usual physical activity
An accelerometer (Actical) will be continuously worn by participants during waking hours (excluding bathing and swimming) for a period of 7 days.The measure of usual physical activity is used to estimate total energy expenditure and energy requirements.
Time frame: Week 1
Diet acceptability
This measurement is an evaluation of palatability, ease of preparation, satisfaction, and perceived benefits and adverse effects related to a prescribed controlled feeding diet.
Time frame: Week 10
Yale Food Addiction Scale
Measures markers of substance dependence with the consumption of high fat/high sugar foods. This is a 25-item self-report measure that includes mixed response categories (dichotomous and Likert-type format).
Time frame: Week 1
Changes in dietary intake
Three non-consecutive twenty-four hour dietary recalls will be collected when subjects are self-selecting their 'usual' diets. A three day average nutrient intake will be expressed.
Time frame: Week 1, 19, and 28
Change in stress reactivity
Acute stress reactivity will be assessed by measuring salivary cortisol concentrations in response to a challenging task.
Time frame: Week 1 and 10
Change in heart rate variability
Autonomic physiological functioning will be assessed using the MindWare Cardio/Galvanic Skin Response (GSR) system, a device that connects to the subject's torso with eight disposable electrodes and a heart rate monitor. Emotional arousal via skin conductance, a form of electrodermal activity (EDA) is also measured.
Time frame: Week 1 and 10
Change in Food Choice
Food choice computer-based tests from Leeds, United Kingdom, will be used to estimate explicit liking and implicit wanting for several different categories of foods.
Time frame: Week 1 and 10
Change in oxygen consumption rate (OCR)
Measured in peripheral blood mononuclear cells by use of Seahorse XF Analyzer, a tool for measuring glycolysis and oxidative phosphorylation (through oxygen consumption) simultaneously in the same cells.
Time frame: Week 1 and 10
Change in extracellular acidification rate (ECAR)
Measured in peripheral blood mononuclear cells by use of Seahorse XF Analyzer, a tool for measuring glycolysis and oxidative phosphorylation (through oxygen consumption) simultaneously in the same cells.
Time frame: Week 1 and 10
Change in fecal microbiome
Assays will be performed on fecal samples to determine DNA representing the colonic microbiota.
Time frame: Week 1, 10 an 28
PDFs hosted by the registry, ClinicalTrials.gov.
Plan to share: Yes — Anonymized metabolomics data will be deposited on Metabolomics Work Bench (https://www.metabolomicsworkbench.org/), a national and international repository for metabolomics data and metadata, developed in support of the National Institutes of Health (NIH) Common Fund Metabolomics Program and housed at the San Diego Supercomputer Center (SDSC), University of California, San Diego. Archived data will include raw data files, quality assurance data, final analytical data, and associated experimental metadata including experimental group assignments, anthropometric, physiological and clinical measures.
Supporting information: Study protocol, Analytic code
Time frame: Immediately following publication. No end date.
Access criteria: Anyone who wishes to access the data.
Ran from Aug 2022 to primary completion in Jul 2026, 47 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 47 months is above 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 Sep 2026. You cannot join it, but the record below documents what was studied.
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USDA, Western Human Nutrition Research Center