DIETFITS Study (Diet Intervention Examining the Factors Interacting With Treatment Success
NCT ID: NCT01826591
Last Updated: 2023-02-21
Study Results
The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.
Basic Information
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COMPLETED
NA
609 participants
INTERVENTIONAL
2013-01-31
2016-05-31
Brief Summary
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Detailed Description
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Mobile App Sub-Study-For the purpose of augmenting adherence to high vegetable consumption in both diet groups, we will develop a theory-based mobile app to increase vegetable consumption through goal-setting, self-monitoring, and social comparison. Participants from both diet groups with iPhones will be re-randomized to receive the app at either months 4-5 or months 7-8. The first phase during months 4-7 will be used to compare the effect of a mobile app (intervention) vs. no mobile app (waiting-list control). The a priori hypothesis is that vegetable consumption will increase among those who receive the app in both diet arms. The investigator and outcomes assessor will be blinded to group assignment. Intention-to-treat analysis will be used.
Conditions
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Study Design
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RANDOMIZED
PARALLEL
TREATMENT
DOUBLE
Study Groups
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Experimental: Low-Carbohydrate Diet
Healthy, Low-Carbohydrate Diet
Low-Carbohydrate Diet
Counseling/instruction on how to follow a low-carbohydrate diet.
Mobile App
Mobile app to increase vegetable consumption. Participants with iPhones will be re-randomized to receive a mobile app beginning at either months 4-5 or months 7-8. The first phase during months 4-7 will be used to compare the effect of a mobile app (intervention) vs. no mobile app (waiting-list control). The a priori hypothesis is that vegetable consumption will increase among those who receive the app in both diet groups.
Experimental: Low-Fat Diet
Healthy, Low-Fat Diet
Low-Fat Diet
Counseling/instruction on how to follow a low-fat diet.
Mobile App
Mobile app to increase vegetable consumption. Participants with iPhones will be re-randomized to receive a mobile app beginning at either months 4-5 or months 7-8. The first phase during months 4-7 will be used to compare the effect of a mobile app (intervention) vs. no mobile app (waiting-list control). The a priori hypothesis is that vegetable consumption will increase among those who receive the app in both diet groups.
Interventions
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Low-Carbohydrate Diet
Counseling/instruction on how to follow a low-carbohydrate diet.
Low-Fat Diet
Counseling/instruction on how to follow a low-fat diet.
Mobile App
Mobile app to increase vegetable consumption. Participants with iPhones will be re-randomized to receive a mobile app beginning at either months 4-5 or months 7-8. The first phase during months 4-7 will be used to compare the effect of a mobile app (intervention) vs. no mobile app (waiting-list control). The a priori hypothesis is that vegetable consumption will increase among those who receive the app in both diet groups.
Eligibility Criteria
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Inclusion Criteria
* Women: Pre-menopausal (self-report) and \<50 years of age
* Men: \<50 years of age
* BMI (body mass index): 27-40 kg/m2 (need to lose \>10% body weight to achieve healthy BMI)
* Body weight stable for the last two months, and not actively on a weight loss plan
* No plans to move from the area over the next two years
* Available and able to participate in the evaluations and intervention for the study period
* Willing to accept random assignment
* To enhance study generalizability, people on medications not noted below as specific exclusions can
* participate if they have been stable on such medications for at least three months
* Ability and willingness to give written informed
* No known active psychiatric illness
Exclusion Criteria
* Pregnant, lactating, within 6 months post-partum, or planning to become pregnant in the next 2 years
* Diabetes (type 1 and 2) or history of gestational diabetes or on hypoglycemic medications for any other indication
* Prevalent diseases: Malabsorption, renal or liver disease, active neoplasms, recent myocardial infarction (\<6 months)(patient self-report and, if available, review of labs from primary care provider)
* Smokers (because of effect on weight and lipids)
* History of serious arrhythmias, or cerebrovascular disease
* Uncontrolled hyper- or hypothyroidism (TSH not within normal limits)
* Medications: Lipid lowering, antihypertensive medications, and those known to affect weight/energy expenditure
* Excessive alcohol intake (self-reported, \>3 drinks/day)
* Musculoskeletal disorders precluding regular physical activity
* Unable to follow either of the two study diets for reasons of food allergies or other (e.g., vegan)
* Currently under psychiatric care, or taking psychiatric medications
* Inability to communicate effectively with study personnel
18 Years
50 Years
ALL
Yes
Sponsors
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Nutrition Science Initiative
OTHER
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
NIH
National Heart, Lung, and Blood Institute (NHLBI)
NIH
National Center for Advancing Translational Sciences (NCATS)
NIH
Stanford University
OTHER
Responsible Party
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Christopher Gardner
Professor of Medicine
Principal Investigators
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Christopher D Gardner, PhD
Role: PRINCIPAL_INVESTIGATOR
Stanford University
Locations
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Stanford University School of Medicine
Stanford, California, United States
Countries
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References
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Mummah SA, Robinson TN, King AC, Gardner CD, Sutton S. IDEAS (Integrate, Design, Assess, and Share): A Framework and Toolkit of Strategies for the Development of More Effective Digital Interventions to Change Health Behavior. J Med Internet Res. 2016 Dec 16;18(12):e317. doi: 10.2196/jmir.5927.
Mummah SA, Mathur M, King AC, Gardner CD, Sutton S. Mobile Technology for Vegetable Consumption: A Randomized Controlled Pilot Study in Overweight Adults. JMIR Mhealth Uhealth. 2016 May 18;4(2):e51. doi: 10.2196/mhealth.5146.
Mummah SA, King AC, Gardner CD, Sutton S. Iterative development of Vegethon: a theory-based mobile app intervention to increase vegetable consumption. Int J Behav Nutr Phys Act. 2016 Aug 8;13:90. doi: 10.1186/s12966-016-0400-z.
Stanton MV, Robinson JL, Kirkpatrick SM, Farzinkhou S, Avery EC, Rigdon J, Offringa LC, Trepanowski JF, Hauser ME, Hartle JC, Cherin RJ, King AC, Ioannidis JP, Desai M, Gardner CD. DIETFITS study (diet intervention examining the factors interacting with treatment success) - Study design and methods. Contemp Clin Trials. 2017 Feb;53:151-161. doi: 10.1016/j.cct.2016.12.021. Epub 2016 Dec 24.
Gardner CD, Trepanowski JF, Del Gobbo LC, Hauser ME, Rigdon J, Ioannidis JPA, Desai M, King AC. Effect of Low-Fat vs Low-Carbohydrate Diet on 12-Month Weight Loss in Overweight Adults and the Association With Genotype Pattern or Insulin Secretion: The DIETFITS Randomized Clinical Trial. JAMA. 2018 Feb 20;319(7):667-679. doi: 10.1001/jama.2018.0245.
Shih CW, Hauser ME, Aronica L, Rigdon J, Gardner CD. Changes in blood lipid concentrations associated with changes in intake of dietary saturated fat in the context of a healthy low-carbohydrate weight-loss diet: a secondary analysis of the Diet Intervention Examining The Factors Interacting with Treatment Success (DIETFITS) trial. Am J Clin Nutr. 2019 Feb 1;109(2):433-441. doi: 10.1093/ajcn/nqy305.
Fielding-Singh P, Patel ML, King AC, Gardner CD. Baseline Psychosocial and Demographic Factors Associated with Study Attrition and 12-Month Weight Gain in the DIETFITS Trial. Obesity (Silver Spring). 2019 Dec;27(12):1997-2004. doi: 10.1002/oby.22650. Epub 2019 Oct 21.
Grembi JA, Nguyen LH, Haggerty TD, Gardner CD, Holmes SP, Parsonnet J. Gut microbiota plasticity is correlated with sustained weight loss on a low-carb or low-fat dietary intervention. Sci Rep. 2020 Jan 29;10(1):1405. doi: 10.1038/s41598-020-58000-y.
Figarska SM, Rigdon J, Ganna A, Elmstahl S, Lind L, Gardner CD, Ingelsson E. Proteomic profiles before and during weight loss: Results from randomized trial of dietary intervention. Sci Rep. 2020 May 13;10(1):7913. doi: 10.1038/s41598-020-64636-7.
Lai CQ, Parnell LD, Das SK, Gardner CD, Ordovas JM. Differential weight-loss responses of APOA2 genotype carriers to low-carbohydrate and low-fat diets: the DIETFITS trial. Obesity (Silver Spring). 2025 Jun;33(6):1048-1057. doi: 10.1002/oby.24288. Epub 2025 May 1.
Krauss RM, Fisher LM, King SM, Gardner CD. Changes in soluble LDL receptor and lipoprotein fractions in response to diet in the DIETFITS weight loss study. J Lipid Res. 2024 Mar;65(3):100503. doi: 10.1016/j.jlr.2024.100503. Epub 2024 Jan 19.
Hauser ME, Hartle JC, Landry MJ, Fielding-Singh P, Shih CW, Qin F, Rigdon J, Gardner CD. Association of dietary adherence and dietary quality with weight loss success among those following low-carbohydrate and low-fat diets: a secondary analysis of the DIETFITS randomized clinical trial. Am J Clin Nutr. 2024 Jan;119(1):174-184. doi: 10.1016/j.ajcnut.2023.10.028. Epub 2023 Nov 4.
Soto-Mota A, Pereira MA, Ebbeling CB, Aronica L, Ludwig DS. Evidence for the carbohydrate-insulin model in a reanalysis of the Diet Intervention Examining The Factors Interacting with Treatment Success (DIETFITS) trial. Am J Clin Nutr. 2023 Mar;117(3):599-606. doi: 10.1016/j.ajcnut.2022.12.014. Epub 2023 Jan 6.
Hartle JC, Zawadzki RS, Rigdon J, Lam J, Gardner CD. Development and evaluation of a novel dietary bisphenol A (BPA) exposure risk tool. BMC Nutr. 2022 Dec 6;8(1):143. doi: 10.1186/s40795-022-00634-4.
Cauwenberghs N, Prunicki M, Sabovcik F, Perelman D, Contrepois K, Li X, Snyder MP, Nadeau KC, Kuznetsova T, Haddad F, Gardner CD. Temporal changes in soluble angiotensin-converting enzyme 2 associated with metabolic health, body composition, and proteome dynamics during a weight loss diet intervention: a randomized trial with implications for the COVID-19 pandemic. Am J Clin Nutr. 2021 Nov 8;114(5):1655-1665. doi: 10.1093/ajcn/nqab243.
Fragiadakis GK, Wastyk HC, Robinson JL, Sonnenburg ED, Sonnenburg JL, Gardner CD. Long-term dietary intervention reveals resilience of the gut microbiota despite changes in diet and weight. Am J Clin Nutr. 2020 Jun 1;111(6):1127-1136. doi: 10.1093/ajcn/nqaa046.
Oppezzo MA, Stanton MV, Garcia A, Rigdon J, Berman JR, Gardner CD. To Text or Not to Text: Electronic Message Intervention to Improve Treatment Adherence Versus Matched Historical Controls. JMIR Mhealth Uhealth. 2019 Apr 9;7(4):e11720. doi: 10.2196/11720.
Guo J, Robinson JL, Gardner CD, Hall KD. Objective versus Self-Reported Energy Intake Changes During Low-Carbohydrate and Low-Fat Diets. Obesity (Silver Spring). 2019 Mar;27(3):420-426. doi: 10.1002/oby.22389. Epub 2019 Jan 22.
Mummah S, Robinson TN, Mathur M, Farzinkhou S, Sutton S, Gardner CD. Effect of a mobile app intervention on vegetable consumption in overweight adults: a randomized controlled trial. Int J Behav Nutr Phys Act. 2017 Sep 15;14(1):125. doi: 10.1186/s12966-017-0563-2.
Related Links
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Study description and results summary
Other Identifiers
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