May 12, 2023
National Institute on Aging (NIA)
The National Institute on Aging (NIA) is issuing this Notice of Special Interest (NOSI) to encourage analyses of the unique research resources generated by the CALERIE (Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy) trial to improve our understanding of the effects of sustained caloric restriction (CR) in humans and its underlying mechanisms. NIA invites applications for innovative research (R01) projects and exploratory research (R21) projects which leverage the CALERIE Phase 2: 1) biological datasets and biospecimens and/or 2) the CALERIE Tracking System (CTS) behavioral database to address novel hypotheses on the following areas:
The CALERIE research resources are broadly accessible to investigators through the NIA Aging Research Biobank. Prior to any submission of an application for the analysis of CALERIE biospecimens, a request to access the CALERIE biospecimens must be submitted to the NIA Aging Research Biobank and approved by the NIA Biobank Scientific Review Committee. Prospective applicants are strongly advised to seek the necessary permissions well in advance of the anticipated submission date for their applications.
Caloric restriction (CR), defined here as a reduction in caloric intake with preserved optimal nutrition, is the only non-pharmacological intervention that has been shown to extend both mean and maximal lifespan across a variety of species, and to delay, or slow, the progression of a wide variety of aging changes and age-related pathologies. The CALERIE trial was the first study to specifically focus on the effects of sustained CR in humans. CALERIE demonstrated the feasibility of sustained CR (for at least two years) and its favorable effects on predictors of longevity and cardiometabolic risk factors.
The CALERIE trial was conducted in two phases. Phase 1 supported pilot/feasibility studies, the results of which informed the design of the full-scale CALERIE Phase 2 trial. The CALERIE Phase 2 trial was a two-year, three-site, randomized controlled trial in young and middle-aged (age range 21-50 years) non-obese (BMI between 22 and 28 kg/m2) healthy men and women. It compared outcomes in a group assigned a target of 25% CR (i.e., a 25% reduction in energy intake below baseline levels) to an ad libitum diet control group. A unique feature of the CALERIE Phase 2 trial design was the objective measurement of caloric intake through the intake-balance method. This was used to calculate energy intake from the difference between changes in energy stores (assessed by dual-energy X-ray absorptiometry (DXA)) and total energy expenditure (TEE) assessed by the doubly labeled water method (DLW). The CALERIE datasets include these measures made at baseline and intervals after the start of the study.
Noteworthy features of the CALERIE trial are the substantial size of the study; the sustained weight loss achieved (not previously attained in any clinical study in non-obese individuals); the comprehensive physiologic, psychologic, quality-of-life, and cognitive assessments conducted; and the extensive collection of biological samples. In addition, to enhance adherence to CR, the CALERIE trial used a Computerized Tracking System (CTS) that included intensive behavioral strategies combined with dietary modifications (i.e., toolbox methodology). Further details on the CALERIE trial can be found on the CALERIE Research Network website. The CALERIE Research Network was established to facilitate outreach to and engagement of the broader scientific community to analyze the CALERIE research resources. Access to the CALERIE datasets and biospecimens is available through the NIA Aging Research Biobank.
Data and Biospecimens:
Several outcome measures related to the following broad categories were assessed at different time points in the CALERIE Phase 2 trial:
In addition, the CALERIE biorepository contains serum, plasma, urine, skeletal muscle (vastus lateralis), and adipose tissue (subcutaneous abdominal) biopsies collected during the course of the trial.
Computerized Tracking System (CTS) adherence strategies and dataset:
The CALERIE intervention employed a Computerized Tracking System (CTS), an intensive behavioral approach coupled with dietary modifications (i.e., toolbox methodology – see below) anticipated to enhance adherence to CR. Specifically, the CALERIE trial used a combination of individualized and group counseling sessions to enhance CR adherence. Individual counseling sessions were used as the primary means of promoting CR adherence, and the group counseling sessions were used to disseminate information to complement the individualized sessions and to provide social support. The CTS was established to track adherence to CR (change in body weight was used as a proxy measure) and to guide individualized counseling sessions in the form of toolbox options (based on an individual's needs and preferences). The toolbox methodology included a series of intervention options and behavioral strategies specifically designed to increase adherence to the intervention; toolbox algorithms allowed tailoring of the treatment to address the unique needs of each participant. Examples of toolbox options included cognitive behavioral strategies, problem-solving strategies, increased training in portion size and caloric estimation skills, and use of structured meal plans. Examples of CTS data include information on the use of toolbox options (e.g., cognitive behavioral strategies, modification of meal patterns), appetite ratings, and individual energy intake targets.
Public Availability of Research Resources generated by the CALERIE Phase 2 trial:
The CALERIE Research Network has instituted two multi-institutional collaborative CALERIE working groups, namely, the Behavioral Working Group and the Molecular Physiology Working Group. The main role of these Working Groups is to promote topic-specific ancillary projects that make use of the CALERIE biospecimens and datasets. Broad participation in the CALERIE Working Groups is welcomed and encouraged. Individuals interested in participating in the CALERIE Working Groups may contact Dr. Kim Huffman (Kim.Huffman@duke.edu) and/or Dr. Cliff Rosen (RosenC@mmc.org). While involvement in the CALERIE Working Groups is welcomed to further and synergize novel research ideas and create new scientific collaborations, participating in the CALERIE Working Groups is not a pre-requisite for applying to the related notices of funding opportunities (NOFOs).
CALERIE biospecimens and related phenotypic and clinical data are available from the Aging Research Biobank. Applications requesting access to these biospecimens/data must follow the steps described in the NIA Biobank User's Guide . Applications will be reviewed by the Biobank Scientific Review Committee. For dates when reviews are conducted and further detailed instructions on requesting access to the biospecimens/data, please also refer to https://agingresearchbiobank.nia.nih.gov/how-to-make-a-request/.
Costs for archiving data that will be made publicly available should be included in the budget. Plans for the creation of a publicly archived database must include adequate dataset documentation and instructions for use by investigators not affiliated with the original study. Provision for easy accessibility of archived datasets is required. Applications requesting inclusion/archival of datasets in the Aging Research Biobank must follow the steps outlined at https://agingresearchbiobank.nia.nih.gov/submit-datasets/. Failure to follow this guidance may negatively impact the funding potential of an application even if the application receives a scientifically meritorious score.
The overarching objective of this NOSI is to incentivize the investigation of key aging biology questions that advance our understanding of the effects of CR on biological, phenotypic, and functional aging and on risk factors for chronic diseases, as well as its underlying cellular and molecular mechanisms. The use of transdisciplinary approaches and new methodologies, such as integrative system technologies, complex data modeling, and analyses of the dynamic pattern of genetic and environmental influences, is of particular relevance and is highly encouraged. Innovative methodologies and integrative analyses that explore multifaceted aspects of aging can ultimately lead to the development of novel therapeutic targets for intervention, CR mimetics, and/or pharmacological approaches that may help to promote healthy aging. Examples of potential research topics guiding analyses of the CALERIE resources that are relevant to this NOSI include the following:
In addition, this NOSI supports secondary data analyses of the CALERIE Computerized Tracking System (CTS) adherence strategies and dataset to explore behavioral aspects of sustained CR in humans.
Examples of potential research topics to explore include but are not limited to:
Applicants are required to include plans for sharing data and results, as well as innovative data analytics approaches (see Goal 3, NIH Strategic Plan For Data Science).
Application and Submission Information
This notice applies to due dates on or after June 5, 2023 and subsequent receipt dates through May 8, 2024.
Submit applications for this initiative using one of the following notices of funding opportunities (NOFOs) or any reissues of these NOFOs through the expiration date of this notice.
All instructions in the SF424 (R&R) Application Guide and the NOFO used for submission must be followed, with the following additions:
Applications nonresponsive to terms of this NOSI will not be considered for the NOSI initiative.
Please direct all inquiries to the contacts in Section VII of the listed notice of funding opportunity with the following additions/substitutions:
We encourage inquiries concerning this NOSI and welcome the opportunity to answer questions from potential applicants.
Chhanda Dutta, Ph.D.
National Institute on Aging (NIA)
Inquiries related to the availability of CALERIE resources from the AgingResearchBiobank, the process to be followed to be granted access to these resources, or the inclusion/archiving of datasets resultant from studies conducted under this NOSI should be directed to:
Rosaly Correa-de-Araujo, MD, M.Sc., Ph.D.
National Institute on Aging
Peer Review Contact(s)
Examine your eRA Commons account for review assignment and contact information (information appears two weeks after the submission due date).
Financial/Grants Management Contact(s)
National Institute on Aging (NIA)