DGA4ME: Metabolic and Bio-behavioral Effects of Following Recommendations in the Dietary Guidelines for Americans
Study Details
Study Description
Brief Summary
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.)
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
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N/A |
Detailed Description
This will be a 32-week study including baseline testing (week 0), increased physical activity in all groups, pre-diet testing (week 5), an 8-week controlled feeding period, post-diet testing (week 14), a follow-up period of dietary education and observation, and end of study testing (week 32). During the 8 week feeding, participants will be randomly assigned one of the following diets:
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DGA Mediterranean diet pattern at sufficient energy level to maintain body weight (energy balance)
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DGA Mediterranean diet pattern at a moderately reduced energy level (negative energy balance)
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TAD diet pattern at a moderately reduced energy level (negative energy balance)
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.
Study Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| Experimental: DGA Mediterranean diet pattern, energy balance 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
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.
|
| Experimental: DGA Mediterranean diet pattern, negative 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
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
|
| Experimental: TAD diet pattern 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 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.
|
Outcome Measures
Primary Outcome Measures
- Change in body weight [Measured weekly for weeks 0 through 14, and weeks 17, 21, 25, 29 and 32]
Body weight will be measured to the nearest 0.1 kg using a calibrated electronic scale.
Secondary Outcome Measures
- Height [Week 0]
Height will be measured to the nearest 0.1 cm using a wall-mounted stadiometer.
- Change in body mass index [Measured weekly for weeks 0 through 14, and weeks 17, 21, 25, 29 and 32]
Body weight and height will be used to calculate Body Mass Index (BMI) as kg/m2.
- Change in body water (via InBody) [Week 0, 5, 14 and 32]
Measured using bioelectrical impedance analysis (BIA) with an InBody 770® expressed as kg.
- Change in body fat (via DEXA scan) [Week 5, 14 and 32]
Fat mass (grams) will be measured using dual energy x-ray absorptiometry (DEXA).
- Change in waist circumference [Week 0, 5, 14 and 32]
Waist circumference is measured with an anthropometric tape. Measurements will be performed in duplicate and averages recorded to the nearest 0.1 cm.
- Change in hip circumference [Week 0, 5, 14 and 32]
Hip circumference is measured with an anthropometric tape. Measurements will be performed in duplicate and averages recorded to the nearest 0.1 cm.
- Change in waist to hip ratio [Week 0, 5, 14 and 32]
Waist and hip circumference will be expressed as a ratio.
- Change in resting systolic blood pressure [Week 0, 5, 14 and 32]
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.
- Change in resting diastolic blood pressure [Week 0, 5, 14 and 32]
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.
- Change in resting heart rate [Week 0, 5, 14 and 32]
Resting heart rate (pulse) will obtained via automated instrument in beats per minute.
- Genetic Risk of Obesity [Week 0]
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).
- Change in vascular health [Week 5, 9 and 14]
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.
- Change in liver fat [Week 0, 5 and 14]
Liver fat assessed from the Controlled Attenuation Parameter (CAP) computed from the liver stiffness measurement using the Fibroscan®
- Change in liver stiffness [Week 0, 5 and 14]
Liver stiffness assessed from the shear wave speed with pulse echo ultrasound using the Fibroscan®
- Change in blood metabolite profiles [Week 5 and 14]
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.
- Change in fasting blood glucose [Week 0, 5, 14 and 32]
This outcome will evaluate blood sugars levels in the fasted state.
- Change in hemoglobin A1C [Week 0, 5, 14 and 32]
This outcome will evaluate glycated hemoglobin as a reflection of the plasma glucose level during the past two to three months.
- Change in urinary sodium [Week 5, 9, 11 and 14]
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.
- Change in urinary potassium [Week 5, 9, 11 and 14]
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.
- Change in urinary nitrogen [Week 5, 9, 11 and 14]
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.
- Change in red blood cell fatty acids [Week 0, 5, 14 and 32]
Red blood cell fatty acids will be analyzed by mass spectrometry (MS).
- Change in C-reactive protein [Week 0, 5, 14 and 32]
C-Reactive Protein will be measured as a non-specific marker for inflammation.
- Change in carotenoid levels [Week 5 and 14]
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.
- Change in total cholesterol [Week 5 and 14]
Total cholesterol will be collected to evaluate cardiac risk expressed as milligrams per deciliter (mg/dL).
- Change in high density lipoprotein (HDL) cholesterol [Week 5 and 14]
HDL cholesterol will be collected to evaluate cardiac risk expressed as milligrams per deciliter (mg/dL).
- Change in low density lipoprotein (LDL) cholesterol [Week 5 and 14]
LDL cholesterol will be collected to evaluate cardiac risk expressed as milligrams per deciliter (mg/dL).
- Change in triglycerides in response to a meal [Baseline and 1, 2, 3, and 6 hours after a challenge meal]
Triglycerides will be measured in blood (mg/dL).
- Change in ghrelin in response to a meal [Baseline and 1, 2, 3, and 6 hours after a challenge meal]
Ghrelin will be evaluated as an indicator of hunger signaling.
- Change in leptin in response to a meal [Baseline and 1, 2, 3, and 6 hours after a challenge meal]
Leptin will be evaluated as an indicator of satiety signaling.
- Change in insulin in response to a meal [Baseline and 1, 2, 3, and 6 hours after a challenge meal]
Insulin measured in blood using an antibody based assay. Will also be expressed as the quantitative insulin sensitivity check index (QUICKI).
- Change in Matsuda Index [Baseline and 1, 2 hours after a challenge meal]
Matsuda index will be calculated from plasma glucose and insulin.
- Change in resting metabolic rate [Week 0, 5 and 14]
Respiratory gas exchange measurements (oxygen consumption-VO2 and carbon dioxide production-VCO2) will be made to determine metabolic rate using a metabolic cart system.
- Change in post-prandial metabolic rate [1, 2, 3 and 6 hours after a meal]
Post-prandial metabolic rate measured using indirect calorimetry.
- Change in metabolic flexibility [Week 5 and 14]
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.
- Change in predicted VO2 max [Week 5, 14 and 32]
Cardiorespiratory endurance will be evaluated by measuring heart rate (HR) and oxygen consumption (VO2) during a walking graded exercise test on a treadmill.
- Change in muscular strength output [Week 0, 5 and 14]
A calibrated back-leg-chest dynamometer (Baseline, New York) will be used to measure isometric muscle strength, recorded in kilograms (kg). Maximal strength (force) for the three trials will be used to determine muscular strength.
- Change in interstitial glucose levels [Week 0-1, 4-5 and 14-15]
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.
- Change in executive function [Week 5 and 14]
Assessed using Cambridge Gambling Task (CGT), from Cambridge Neuropsychological Test Automated Battery (CANTAB).
- Change in response speed [Week 5 and 14]
Assessed using Motor Screening Task (MOT), from Cambridge Neuropsychological Test Automated Battery (CANTAB).
- Change in verbal memory [Week 5 and 14]
Assessed using Verbal Recognition Memory (VRM) task from Cambridge Neuropsychological Test Automated Battery (CANTAB).
- Change in psycho-motor speed [Week 5 and 14]
Assessed using Reaction Time (RTI) task from Cambridge Neuropsychological Test Automated Battery (CANTAB).
- Change in spatial memory [Week 5 and 14]
Assessed using Spatial Working Memory (SWM) task from Cambridge Neuropsychological Test Automated Battery (CANTAB).
- Change in multitasking [Week 5 and 14]
Assessed using Multitasking Test (MTT) from Cambridge Neuropsychological Test Automated Battery (CANTAB).
- Change in social cognition [Week 5 and 14]
Assessed using Emotional Recognition (ERT) task from Cambridge Neuropsychological Test Automated Battery (CANTAB).
- Change in attentive function [Week 5 an 14]
Assessed using Stop Signal Task (STT) from Cambridge Neuropsychological Test Automated Battery (CANTAB).
- Change in allostatic load [Week 0, 5, 14 and 32]
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.
- Change in continuous systolic blood pressure [Week 0, 5 and 14]
Blood pressure measured using a Continuous Non-invasive Arterial Pressure (CNAP®) device in mmHg.
- Change in continuous diastolic blood pressure [Week 0, 5 and 14]
Blood pressure measured using a Continuous Non-invasive Arterial Pressure (CNAP®) device in mmHg.
- Change in mean arterial blood pressure [Week 0, 5 and 14]
Blood pressure measured using a Continuous Non-invasive Arterial Pressure (CNAP®) device in mmHg .
- Change in mood [Week 0, 5, 14]
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.
- Change in perceived stress [Week 0, 5, 10, 14, 23 and 32]
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.
- Change in self-efficacy [Week 0, 14, 23 and 32]
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.
- Change in diet satisfaction [Week 0, 23 and 32]
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.
- Change in appetite [Week 5 and 14]
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.
- Wheaton chronic stress scale [Week 0]
Participants will complete a questionnaire of 51 items about common life conditions and situations (e.g., financial issues, work, love and marriage, family and children, social life).
- Trier inventory of chronic stress [Week 0]
This measurement is a standardized questionnaire that measures six aspects of chronic stress: work overload, work discontent, social stress, lack of social recognition, worries, and intrusive memories.
- Three factor eating inventory [Week 0]
This 51 item questionnaire is used to examine three dimensions of human eating behavior including cognitive restraint (CR), uncontrolled eating (UE) and emotional eating (EE). Instrument has three subscales, combining likert scales and true/false questions. Subscales include cognitive restraint (score can range from 0 to 21), disinhibition (score can range from 0 to 16) and hunger (score can range from 0 to 14).
- Power of food scale [Week 0]
This measurement is a questionnaire used to assess the psychological influence of the mere presence or availability of food. Power of food questionnaire measured once on a 5 point likert scale.
- Barriers to physical activity [Week 0]
Participants will be asked to complete the Barriers to Being Active questionnaire.
- Usual physical activity [Week 0]
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.
- Eating behavior [Week 0]
Dutch eating behavior questionnaire measured once. Scale is a 5-point likert scale. Sub scales include restrained eating, emotional eating, and external eating. Scores will be reported separately for each subscale.
- Diet acceptability [Week 14]
This measurement is an evaluation of palatability, ease of preparation, satisfaction, and perceived benefits and adverse effects related to a prescribed controlled feeding diet.
- Food craving inventory [Week 5]
A 50 item self-report measure of general and specific food cravings. The food craving inventory consists of four factors or scales measuring cravings for high fats, carbohydrates/starches, sweets, and fast food fats.
- Yale Food Addiction Scale [Week 5]
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).
- Changes in dietary intake [Week 0, 23 and 32]
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.
- Change in stress reactivity [Week 0, 5 and 14]
Acute stress reactivity will be assessed by measuring salivary cortisol concentrations in response to a challenging task.
- Change in heart rate variability [Week 5 and 14]
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.
- Change in Food Choice [Week 5 and 14]
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.
- Change in oxygen consumption rate (OCR) [Week 5 and 14]
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.
- Change in extracellular acidification rate (ECAR) [Week 5 and 14]
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.
- Change in fecal microbiome [Week 0, 5, 14 an 32]
Assays will be performed on fecal samples to determine DNA representing the colonic microbiota.
- Focus group [Week 32]
Focus groups will be conducted in the form of a group discussion of six participants. The goal of the focus groups is to provide qualitative data about lifestyle and dietary behaviors. Focus groups will be audio recorded and transcribed.
Eligibility Criteria
Criteria
Inclusion Criteria:
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Body Mass Index (BMI) 27-39.9 kg/m2 or 32-50% body fat percentage
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Willingness to have blood drawn
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The criteria listed above and at least one of the following: Fasting glucose ≥100 mg/dL but <126 mg/dL or Fasting triglyceride ≥125 mg/dL or HDL-cholesterol ≤50 mg/dL or Blood Pressure (BP): Systolic BP ≥130 mmHg or Diastolic BP ≥85 mmHg or Hemoglobin A1C ≥ 5.7 and <6.5%
Exclusion Criteria:
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Active participation in another research study
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Tested positive for COVID-19 within the past 10 days
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Been in close contact with a COVID-19 positive person within the past 14 days
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Blood Pressure (BP): Systolic BP ≥140 mmHg or Diastolic BP ≥90 mmHg
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LDL cholesterol ≥190 mg/dL
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Triglycerides ≥500 mg/dL
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Current use of smoking or chewing tobacco, e-cigarettes, cigars, vaping, cannabis or other use of nicotine containing products (within the past 6 months)
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Current use of dietary supplements and/or unwillingness to cease intake of dietary supplements
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Vegan or vegetarian lifestyle or any other dietary restrictions that would interfere with consuming the intervention foods and beverages (including dietary intolerances, allergies and sensitivities)
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Unwillingness to consume intervention foods and beverages
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Engage in more than moderate drinking (> 1 drink serving per day) or binge drinking (4 drinks within two hours).
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Unwillingness to cease alcohol intake as required for specific duration of the study
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Excessive intake of caffeine containing products (excessive defined as ≥ 400 mg/day)
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Unwillingness to refrain from caffeine intake on lab visit days.
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Intentional weight change of ≥5% of body weight within 6 months of entry into the study
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Diagnosis of disordered eating or eating disorder
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Recent diagnosis of any of the following or measurement on screening lab tests: Anemia (hemoglobin <11.7 g/dL) or abnormal liver or thyroid function (defined as liver enzymes that are >200% of upper limit (ALT upper limit is 43 U/L or Aspartate transaminase (AST) upper limit is 54 U/L) and thyroid function tests: Thyroxine (T4, free) <0.56 or >1.64 ng/dL; Thyroid-stimulating hormone (TSH) <0.35 or >5.6 μIU/mL).
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History of any of the following: Gastric bypass surgery, inflammatory bowel disease (IBD) or other GI conditions that would interfere with consuming the intervention foods, active cancer in the past three years excluding squamous or basal cell carcinomas of the skin that have been handled medically by local excision and other serious medical conditions
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Recent dental work or have conditions of the oral cavity that would interfere with consuming the intervention foods and beverages
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Taking any medication in the class of antipsychotics
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Long term use of antibiotics
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Taking any over the counter or prescribed medication for any of the following: Elevated lipids, elevated glucose, high blood pressure, weight loss or conditions that require corticosteroids (e.g. asthma, arthritis or eczema).
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Are pregnant, planning to become pregnant within the duration of the study or breastfeeding.
Contacts and Locations
Locations
| Site | City | State | Country | Postal Code | |
|---|---|---|---|---|---|
| 1 | UC Davis, Western Human Nutrition Research Center | Davis | California | United States | 95616 |
Sponsors and Collaborators
- USDA, Western Human Nutrition Research Center
Investigators
- Principal Investigator: Kevin D Laugero, PhD, USDA, Western Human Nutrition Research Center
Study Documents (Full-Text)
None provided.More Information
Additional Information:
Publications
- FL111