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Calorie RestrictionNCT05651620

The CALERIE™ Legacy Study

An observational study of Calorie Restriction, run by Tufts University at 3 sites in United States.

Active, not recruiting

Under way, not looking for participants. Everyone needed has enrolled. The study is still running.

Official record
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Trial summary

The purpose of the CALERIE Legacy Study is to follow up on the health and wellness of participants from phase 2 of the Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy (CALERIE) trial, which was conducted from 2007 to 2011. Read more about this study

Who is it for?
Ages 33 to 70 yearsHealthy volunteers can take part
Conditions the study is for
Calorie Restriction
How many people
216 participants
Where
3 sitesUnited States
Study dates
6 Apr 2023to 31 Jan 2028
Phase
Observational
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 33 to 70 years
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Study population: All CALERIE participants, except those who are deceased, are known not to qualify, or did not start their allocated group (CR intervention or ad libitum control) (n = 4), have been identified as potential subjects (n = 216) in the CALERIE Legacy Study. The demographic profile of this study is expected to be similar to that of the CALERIE trial, which was 70.4% female. Healthy individuals without obesity of either sex and all race and ethnic groups were eligible to participate in the CALERIE trial. However, due to safety concerns, pregnant women were excluded, and to avoid confounding from peri- and post-menopausal status, the upper age limit for women was 47 years. Upon enrollment, CALERIE participants were 21-50y, 77.3% White, 12% Black, and 10.7% other; ethnicity was 97% non-Hispanic.

Who may be able to join

  • Enrolled in the CALERIE trial and started their allocated group (CR intervention or ad libitum control condition)
  • Willing and able to attend one of the clinical sites for an in-person visit and provide informed consent

Who cannot join

  • Pregnant women
  • Women less than 12 months postpartum
  • Documented note from the CALERIE trial indicating that the subject should not be contacted or requested not to be contacted for future research
  • Diagnosed active cancer or terminal illness

Trial locations and contacts

3 sites in 1 country.

United States3 sites
  • Pennington Biomedical Research Center

    Baton Rouge, Louisiana, 70808

  • Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University

    Boston, Massachusetts, 02111

  • Washington University School of Medicine

    St Louis, Missouri, 63110-1010

Other trials in United States

About this study

Official title: Legacy Effects of CALERIE™, a 2-year Calorie Restriction Intervention, on Hallmarks of Healthspan and Aging

The purpose of the CALERIE Legacy Study is to follow up on the health and wellness of participants from phase 2 of the Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy (CALERIE) trial, which was conducted from 2007 to 2011.

Read the detailed description

The CALERIE Legacy Study is an observational follow-up study of participants from phase 2 the CALERIE trial, the first randomized controlled trial of calorie restriction (CR) in humans without obesity. The overarching goal of the CALERIE Legacy Study is to examine whether two years of CR results in sustained improvements in the biological, phenotypic, and functional hallmarks of human aging 10 to 15 years after the structured intervention. Participants will complete clinical assessments, dietary recalls, and questionnaires, and laboratory evaluations will be performed on blood and urine samples. The study also includes an optional biospecimen banking component.

Keywords
calorie restriction, dietary intervention, biological aging, behavioral data

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

Study groups in NCT05651620
Study groupRoleWhat they receive
Calorie Restriction (CR)Individuals in the CR group were prescribed a 25% reduction from their baseline energy intake during the two-year CALERIE trial.
Ad Libitum (AL)Individuals in the AL group were asked to continue their usual dietary intake during the two-year CALERIE trial.

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Biological age - Klemera-Doubal Method

    Biological age will be quantified by the Klemera-Doubal Method (KDM), an algorithm-based measure. Biological age is expressed in years.

    Measured: 11-16 years post CALERIE trial

  2. Healthspan

    Healthspan will be assessed by sex-specific metabolic syndrome z-score (MS z-score). MS z-score was developed using high density lipoprotein cholesterol (HDL), triglycerides (TG), waist circumference (WC), fasting blood glucose (FBG), and mean arterial pressure (MAP = [systolic blood pressure + 2 x diastolic blood pressure]/3). SDs for HDL and WC in the equations are sex specific.

    Women: MS z-score = [45-HDL]/SDHDLW+ [TG-150]/SDTG + [WC-88]/SDWCW + [FBG-100]/SDFBG + [MAP -100]/SDMAP

    Men: MS z-score = [40-HDL]/SDHDLM+ [TG-150]/SDTG + [WC-102]/SDWCM + [FBG-100]/SDFBG + [MAP -100]/SDMAP

    W = women M = men

    This score does not have a unit.

    Measured: 11-16 years post CALERIE trial

Secondary outcomes (108)
  1. Biological age - Homeostatic Dysregulation

    Biological age will be quantified by homeostatic dysregulation, an algorithm-based measure. Biological age is expressed in years.

    Measured: 11-16 years post CALERIE trial

  2. Biological age - Levine Phenotypic Age

    Biological age will be quantified by Levine Phenotypic Age, an algorithm-based measure. Biological age is expressed in years.

    Measured: 11-16 years post CALERIE trial

  3. Height

    Height will be measured in cm.

    Measured: 11-16 years post CALERIE trial

  4. Weight

    Weight will be measured in kg.

    Measured: 11-16 years post CALERIE trial

  5. Waist circumference

    Weight circumference will be measured in cm.

    Measured: 11-16 years post CALERIE trial

  6. Hip circumference

    Hip circumference will be measured in cm.

    Measured: 11-16 years post CALERIE trial

  7. Body mass index (BMI)

    BMI (kg/m2) will be calculated using height and weight measurements.

    Measured: 11-16 years post CALERIE trial

  8. Blood pressure

    Systolic and diastolic blood pressure will be measured in mmHg.

    Measured: 11-16 years post CALERIE trial

  9. Pulse rate at rest

    Pulse rate will be measured in beats/min.

    Measured: 11-16 years post CALERIE trial

  10. Respiration rate at rest

    Respiration rate will be measured in breaths/min.

    Measured: 11-16 years post CALERIE trial

  11. Fat mass

    Whole-body fat mass (kg, %) as measured by dual-energy X-ray absorptiometry.

    Measured: 11-16 years post CALERIE trial

  12. Fat-free mass

    Whole-body fat-free mass (kg, %) as measured by dual-energy X-ray absorptiometry.

    Measured: 11-16 years post CALERIE trial

  13. Bone mineral content

    Whole-body bone mineral content (g) as measured by dual-energy X-ray absorptiometry.

    Measured: 11-16 years post CALERIE trial

  14. Resting metabolic rate (RMR)

    RMR will be measured in kcal/d by indirect calorimetry using a ventilated hood system.

    Measured: 11-16 years post CALERIE trial

  15. Respiratory quotient (RQ)

    RQ will be measured by indirect calorimetry using a ventilated hood system. This is a ratio (V̇CO2/V̇O2) and does not have a unit.

    Measured: 11-16 years post CALERIE trial

  16. Maximal aerobic capacity (V̇O2max)

    Maximal aerobic capacity (V̇O2max) will be measured in mL/kg/min using the Cornell incremental treadmill test.

    Measured: 11-16 years post CALERIE trial

  17. Interleukin-6 (IL-6)

    IL-6, a blood-based biomarker of aging proposed by the Targeting Aging with MEtformin (TAME) Biomarkers Workgroup, will be measured in pg/mL.

    Measured: 11-16 years post CALERIE trial

  18. Insulin - TAME panel

    Insulin, a blood-based biomarker of aging proposed by the TAME Biomarkers Workgroup, will be measured in μIU/mL.

    Measured: 11-16 years post CALERIE trial

  19. Insulin - 0 min (OGTT)

    Insulin (μIU/mL) will be measured at 0 minutes (pre-dose) during an oral glucose tolerance test (OGTT) to evaluate glucoregulatory response.

    Measured: 11-16 years post CALERIE trial

  20. Insulin - 30 min (OGTT)

    Insulin (μIU/mL) will be measured at 30 minutes post dose during an OGTT to evaluate glucoregulatory response.

    Measured: 11-16 years post CALERIE trial

  21. Insulin - 60 min (OGTT)

    Insulin (μIU/mL) will be measured at 60 minutes post dose during an OGTT to evaluate glucoregulatory response.

    Measured: 11-16 years post CALERIE trial

  22. Insulin - 90 min (OGTT)

    Insulin (μIU/mL) will be measured at 90 minutes post dose during an OGTT to evaluate glucoregulatory response.

    Measured: 11-16 years post CALERIE trial

  23. Insulin - 120 min (OGTT)

    Insulin (μIU/mL) will be measured at 120 minutes post dose during an OGTT to evaluate glucoregulatory response.

    Measured: 11-16 years post CALERIE trial

  24. Insulin-like growth factor 1 (IGF-1)

    IGF-1, a blood-based biomarker of aging proposed by the TAME Biomarkers Workgroup, will be measured in ng/mL.

    Measured: 11-16 years post CALERIE trial

  25. Hemoglobin A1c (HbA1c)

    HbA1c, a blood-based biomarker of aging proposed by the TAME Biomarkers Workgroup, will be measured in mmol/mol.

    Measured: 11-16 years post CALERIE trial

  26. Tumor necrosis factor α receptor II (TNFRII)

    TNFRII, a blood-based biomarker of aging proposed by the TAME Biomarkers Workgroup, will be measured in ng/mL.

    Measured: 11-16 years post CALERIE trial

  27. High-sensitivity C-reactive protein (hsCRP)

    hsCRP, a blood-based biomarker of inflammation, will be measured in μg/mL.

    Measured: 11-16 years post CALERIE trial

  28. Growth/differentiation factor 15 (GDF15)

    GDF15, a blood-based biomarker of aging proposed by the TAME Biomarkers Workgroup, will be measured in pg/mL.

    Measured: 11-16 years post CALERIE trial

  29. Cystatin C

    Cystatin C, a blood-based biomarker of aging proposed by the TAME Biomarkers Workgroup, will be measured in mg/L.

    Measured: 11-16 years post CALERIE trial

  30. N-terminal B-type natriuretic peptide (NT-proBNP)

    NT-proBNP, a blood-based biomarker of aging proposed by the TAME Biomarkers Workgroup, will be measured in pg/mL.

    Measured: 11-16 years post CALERIE trial

  31. Senescence-associated secretory phenotype (SASP) proteins

    SASP proteins, blood-based biomarkers of cellular senescence, will be measured using a SASP panel.

    Measured: 11-16 years post CALERIE trial

  32. Urinary Isoprostanes - iPF(2α)-III

    Urinary iPF(2α)-III, a biomarker of systemic oxidative stress, will be measured in ng/mL.

    Measured: 11-16 years post CALERIE trial

  33. Urinary Isoprostanes - 2,3-dinor-iPF(2α)-III

    Urinary 2,3-dinor-iPF(2α)-III, a biomarker of systemic oxidative stress, will be measured in ng/mL.

    Measured: 11-16 years post CALERIE trial

  34. Urinary Isoprostanes - iPF(2α)-VI

    Urinary iPF(2α)-VI, a biomarker of systemic oxidative stress, will be measured in ng/mL.

    Measured: 11-16 years post CALERIE trial

  35. Urinary Isoprostanes - 8,12-iso-iPF(2α)-VI

    Urinary 8,12-iso-iPF(2α)-VI, a biomarker of systemic oxidative stress, will be measured in ng/mL.

    Measured: 11-16 years post CALERIE trial

  36. Creatinine

    Creatinine, a byproduct of routine activity in the muscle, will be measured in urine in mg/mL.

    Measured: 11-16 years post CALERIE trial

  37. Dehydroepiandrosterone (DHEA)

    DHEA, a blood-based steroid hormone, will be measured in μg/dL.

    Measured: 11-16 years post CALERIE trial

  38. Interleukin 1 beta (IL-1b)

    IL-1b, a blood-based marker of inflammation, will be measured in pg/mL.

    Measured: 11-16 years post CALERIE trial

  39. Interleukin 8 (IL-8)

    IL-8, a blood-based marker of inflammation, will be measured in pg/mL.

    Measured: 11-16 years post CALERIE trial

  40. Tumor necrosis factor α (TNF-α)

    TNF-α, a blood-based marker of inflammation, will be measured in pg/mL.

    Measured: 11-16 years post CALERIE trial

  41. Insulin-like growth factor-binding protein 1 (IGFBP-1)

    IGFBP-1, a blood-based transport protein, will be measured in ng/mL.

    Measured: 11-16 years post CALERIE trial

  42. Transforming growth factor beta 1 (TGFB1)

    TGFB1, a blood-based marker of immune function, will be measured in ng/mL.

    Measured: 11-16 years post CALERIE trial

  43. Insulin-like growth factor-binding protein 3 (IGFBP-3)

    IGFBP-3, a blood-based transport protein, will be measured in ng/mL.

    Measured: 11-16 years post CALERIE trial

  44. Platelet-derived growth factor-AB (PDGF-AB)

    PDGF-AB, a blood-based marker of cellular function, will be measured in ng/mL.

    Measured: 11-16 years post CALERIE trial

  45. Intercellular Adhesion Molecule 1 (ICAM-1)

    ICAM-1, a blood-based marker of inflammation, will be measured in ng/mL.

    Measured: 11-16 years post CALERIE trial

  46. Growth hormone

    Growth hormone, a blood-based bio-marker of cellular function, will be measured in ng/mL.

    Measured: 11-16 years post CALERIE trial

  47. Monocyte Chemoattractant Protein 1 (MCP1)

    MCP1, a blood-based marker of inflammation, will be measured in pg/mL.

    Measured: 11-16 years post CALERIE trial

  48. Leptin

    Leptin, a hormonal regulator of energy balance, will be measured in pg/mL.

    Measured: 11-16 years post CALERIE trial

  49. Total adiponectin

    Total adiponectin, a protein hormone that regulates several metabolic processes, including glucose regulation and fatty acid oxidation, will be measured in μg/mL.

    Measured: 11-16 years post CALERIE trial

  50. High molecular weight adiponectin

    High molecular weight adiponectin, a protein hormone that regulates several metabolic processes, including glucose regulation and fatty acid oxidation, will be measured in μg/mL.

    Measured: 11-16 years post CALERIE trial

  51. Muscle strength - Knee extension (60°)

    Knee extension at 60 degrees per second will be measured by isokinetic dynamometry and expressed in Nm.

    Measured: 11-16 years post CALERIE trial

  52. Muscle strength - Knee extension (180°)

    Knee extension at 180 degrees per second will be measured by isokinetic dynamometry and expressed in Nm.

    Measured: 11-16 years post CALERIE trial

  53. Muscle strength - Knee flexion (60°)

    Knee flexion at 60 degrees per second will be measured by isokinetic dynamometry and expressed in Nm.

    Measured: 11-16 years post CALERIE trial

  54. Muscle strength - Knee flexion (180°)

    Knee flexion at 180 degrees per second will be measured by isokinetic dynamometry and expressed in Nm.

    Measured: 11-16 years post CALERIE trial

  55. Handgrip Strength

    Handgrip strength will be measured via a hand dynamometer and expressed in kg.

    Measured: 11-16 years post CALERIE trial

  56. Physical functioning

    Physical functioning as measured by a physical performance battery. This physical performance battery provides a composite score ranging from 0 to 12 and includes results from the balance, gait and chair stand tests.

    Measured: 11-16 years post CALERIE trial

  57. Cognition

    Cognition as measured by the Cambridge Neuropsychological Test Automated Battery (CANTAB). The CANTAB evaluates six main areas of cognitive function: reaction time; verbal recognition memory; intra-extra dimensional set shift; rapid visual information processing; delayed matching to sample; and spatial working memory.

    Measured: 11-16 years post CALERIE trial

  58. Dietary intake - calories

    Dietary intake in calories (kcals/day), as measured by multiple-pass 24-hour dietary recalls and Nutrition Data System for Research (NDSR) software.

    Measured: 11-16 years post CALERIE trial

  59. Dietary intake - carbohydrates

    Dietary carbohydrates (grams and % of energy intake) will be measured by multiple-pass 24-hour dietary recalls and Nutrition Data System for Research (NDSR) software.

    Measured: 11-16 years post CALERIE trial

  60. Dietary intake - proteins

    Dietary proteins (grams and % of energy intake) will be measured by multiple-pass 24-hour dietary recalls and Nutrition Data System for Research (NDSR) software.

    Measured: 11-16 years post CALERIE trial

  61. Health-related quality of life

    Quality of life as measured by the RAND 36-Item Short Form Survey (SF-36). The RAND SF-36 measures eight aspects of health: physical functioning, role limitations due to physical health problems, role limitations due to personal or emotional problems, energy/fatigue, emotional well-being, social functioning, bodily pain, and general health perceptions. It also includes a single item that provides an indication of perceived change in health. Each item is on a 3- or 5-point Likert scale (1-3 or 1-5). Each response is transformed to a recoded value of 0-100, and the transformed scores of the 9 subscales are averaged to derive a composite score. Higher scores indicate more favorable health states.

    Measured: 11-16 years post CALERIE trial

  62. Depression status

    Depression status as measured by the Beck Depression Inventory II (BDI-II). The 21-item BDI-II measures depression severity. The score range is 0-63, with higher scores indicating greater depression severity. Nineteen items are on a 4-point Likert scale (0-3). Two items are on a 7-point Likert scale, and responses are scaled to 0-3. The values are summed to calculate the total score.

    Measured: 11-16 years post CALERIE trial

  63. Mood

    Mood as measured by the Profile of Mood States Second Edition (POMS 2). The POMS 2 assesses six mood subscales using 65 items, each on a 5-point Likert scale (0-4): tension-anxiety (9 items, score range 0-36), depression-dejection (15 items, range 0-60), anger-hostility (12 items, range 0-48), vigor-activity (8 items, range 0-32), fatigue-inertia (7 items, range 0-28), and confusion-bewilderment (7 items, range 0-28). High vigor-activity scores reflect a good mood or emotion, and low scores in the other subscales reflect a good mood or emotion. Total mood disturbance, which is calculated by subtracting the vigor subscale score from the total subscale score (range 0-200), also will be assessed.

    Measured: 11-16 years post CALERIE trial

  64. Sleep

    Sleep as measured by the Pittsburgh Sleep Quality Index (PSQI). The PSQI measures sleep quality and disturbance over the course of one month using seven subscales: subjective sleep quality; sleep latency; sleep duration; habitual sleep efficiency; sleep disturbances; use of sleeping medication; and daytime dysfunction. The scoring range of each subscale is 0-3. The scoring range of the Global PSQI (the composite score of the seven subscales) is 0-21. For both the subscales and Global PSQI, higher scores indicate greater difficulties with sleeping.

    Measured: 11-16 years post CALERIE trial

  65. Sexual function

    Sexual function as measured by the Derogatis Interview for Sexual Functioning - Self Report (DISF-SR). Both versions of the DISF-SR (male and female) are scored from 20 to 75, with higher scores indicating higher sexual functioning.

    Measured: 11-16 years post CALERIE trial

  66. Food cravings

    Food cravings as measured by the Food Cravings Questionnaire-Trait (FCQ-T). The FCQ-T measures frequency and intensity of food cravings. It has 39 items on a 6-point Likert scale (1-6) and a score range of 39-234. Higher scores indicate more frequent and intense food cravings. Scores on all items are summed for a total score.

    Measured: 11-16 years post CALERIE trial

  67. Dietary restraint, disinhibition, and hunger

    Dietary restraint, disinhibition, and hunger as measured by the Three-Factor Eating Questionnaire (TFEQ). The 51-item TFEQ will be used to measure dietary restraint (21 items), disinhibition (16 items), and hunger (14 items). Item responses are scored as 0 or 1 and summed. Higher scores indicate higher levels of restrained eating (range 0-21), disinhibited eating (range 0-16), and predisposition to hunger (range 0-14).

    Measured: 11-16 years post CALERIE trial

  68. Disordered eating

    Disordered eating as measured by the Multiaxial Assessment of Eating Disorder Symptoms (MAEDS). MAEDS will be used to assess six domains of disordered eating: binge eating (range 8-56), restrictive eating (range 9-63), purgative behavior (range 7-49), fear of fatness (range 11-77), avoidance of forbidden foods (range 10-70), and depression (range 11-77).

    Measured: 11-16 years post CALERIE trial

  69. Body shape perceptions

    Body shape perceptions as measured by the Body Shape Questionnaire (BSQ). Items on the BSQ are rated on a 6-point Likert-type scale. The score ranges from 34-204 points. Higher scores indicate increased concern regarding body shape.

    Measured: 11-16 years post CALERIE trial

  70. Physical activity

    Physical activity as measured by the 7-Day Stanford Physical Activity Recall (PAR). The PAR estimates an individual's time spent in sleep and physical activity for the 7 days prior to the interview. Energy expenditure based on time spent in sleep and physical activities can be estimated. Sub-scores of energy expenditure for each of the following activities are calculated, summed, and averaged to estimate energy expenditure as kilocalories per day: sleep, moderate physical activity, hard physical activity, and very hard physical activity. Higher scores indicate greater physical activity per day. Metabolic equivalent (MET) value for each activity is provided: 1 MET for sleep, 4 METs for moderate activity, 6 METs for hard activity, and 10 METs for very hard activity. Time spent in each activity over 7 days is multiplied by the appropriate MET value. The minimum value for each activity is zero; there is no maximum value.

    Measured: 11-16 years post CALERIE trial

  71. Resilience

    Resilience as measured by the 25-item Connor-Davidson Resilience Scale (CD-RISC-25). CD-RISC-25 is scored from 0 to 100, with higher scores indicating higher resilience.

    Measured: 11-16 years post CALERIE trial

  72. Total cholesterol

    Total cholesterol will be measured in mg/dL using a standard lipid panel.

    Measured: 11-16 years post CALERIE trial

  73. High-density lipoprotein cholesterol (HDL-C)

    HDL-C will be measured in mg/dL using a standard lipid panel.

    Measured: 11-16 years post CALERIE trial

  74. Triglycerides

    Triglycerides will be measured in mg/dL using a standard lipid panel.

    Measured: 11-16 years post CALERIE trial

  75. Low-density lipoprotein cholesterol (LDL-C)

    LDL-C will be calculated in mg/dL using measured values of total cholesterol, HDL-C, and triglycerides.

    Measured: 11-16 years post CALERIE trial

  76. Glucose - 0 min (OGTT)

    Glucose (mg/dL) will be measured at 0 minutes (pre-dose) during an OGTT to evaluate glucoregulatory response.

    Measured: 11-16 years post CALERIE trial

  77. Glucose - 30 min (OGTT)

    Glucose (mg/dL) will be measured at 30 minutes post dose during an OGTT to evaluate glucoregulatory response.

    Measured: 11-16 years post CALERIE trial

  78. Glucose - 60 min (OGTT)

    Glucose (mg/dL) will be measured at 60 minutes post dose during an OGTT to evaluate glucoregulatory response.

    Measured: 11-16 years post CALERIE trial

  79. Glucose - 90 min (OGTT)

    Glucose (mg/dL) will be measured at 90 minutes post dose during an OGTT to evaluate glucoregulatory response.

    Measured: 11-16 years post CALERIE trial

  80. Glucose - 120 min (OGTT)

    Glucose (mg/dL) will be measured at 120 minutes post dose during an OGTT to evaluate glucoregulatory response.

    Measured: 11-16 years post CALERIE trial

  81. Insulin resistance

    Insulin resistance will be calculated using the Homeostatic Model Assessment (HOMA) and measured values of fasting glucose (mmol/L) and fasting insulin (μ/L): (fasting glucose × fasting insulin) ∕ 22.5

    Measured: 11-16 years post CALERIE trial

  82. Beta-cell function

    Beta-cell function will be calculated using HOMA-β and measures of fasting insulin (μ/L) and fasting glucose (mg/dL): HOMA-β (%) = (360 × fasting insulin) ∕ (fasting glucose - 63)

    Measured: 11-16 years post CALERIE trial

  83. Insulinogenic Index

    Insulinogenic index will be calculated as the ratio of change in plasma insulin (I) from 0 to 30 min of the OGTT to the change in plasma glucose (G) over the same period (∆I0-30 min ∕ ∆G0-30 min).

    Measured: 11-16 years post CALERIE trial

  84. Insulin Sensitivity Index (ISI)

    Insulin sensitivity index will be calculated as 1 ∕ fasting insulin (μ/L).

    Measured: 11-16 years post CALERIE trial

  85. Oral Disposition Index

    The Oral Disposition Index will be calculated as the product of insulinogenic index and insulin sensitivity index.

    Measured: 11-16 years post CALERIE trial

  86. Triiodothyronine (T3)

    T3, a blood-based marker of thyroid function, will be measured in ng/dL.

    Measured: 11-16 years post CALERIE trial

  87. Thyroxine (T4)

    T4, a blood-based marker of thyroid function, will be measured in ng/dL.

    Measured: 11-16 years post CALERIE trial

  88. Thyroid stimulating hormone (TSH)

    TSH, a blood-based marker of thyroid function, will be measured in μIU/mL.

    Measured: 11-16 years post CALERIE trial

  89. Alkaline phosphatase (ALKP)

    ALKP, a blood-based marker of liver function, will be measured in IU/L.

    Measured: 11-16 years post CALERIE trial

  90. Alanine transaminase (ALT)

    ALT, a blood-based marker of liver function, will be measured in U/L.

    Measured: 11-16 years post CALERIE trial

  91. Aspartate aminotransferase (AST)

    AST, a blood-based marker of liver function, will be measured in U/L.

    Measured: 11-16 years post CALERIE trial

  92. Albumin

    Albumin, a blood-based marker of liver and kidney function, will be measured in g/dL.

    Measured: 11-16 years post CALERIE trial

  93. Blood Urea Nitrogen (BUN)

    BUN, a blood-based marker of kidney function, will be measured in mg/dL.

    Measured: 11-16 years post CALERIE trial

  94. Total Proteins

    Total proteins are computed as a sum of albumin and globulin. Total proteins are indicative of blood vessel and immune system function and will be measured in g/dL.

    Measured: 11-16 years post CALERIE trial

  95. Bilirubin

    Bilirubin, a blood-based marker of liver function, will be measured in mg/dL.

    Measured: 11-16 years post CALERIE trial

  96. Creatine Phosphokinase (CPK)

    CPK, an enzyme marker of energy homeostasis, will be measured in U/L.

    Measured: 11-16 years post CALERIE trial

  97. Lactate Dehydrogenase (LDH)

    LDH, an enzyme marker of liver function, will be measured in U/L.

    Measured: 11-16 years post CALERIE trial

  98. Globulin

    Globulin, a blood-based marker of liver function, will be measured in g/dL.

    Measured: 11-16 years post CALERIE trial

  99. Albumin/Globulin (A/G) ratio

    A/G ratio is a blood-based marker used to monitor nutritional status and immune system, kidney, and liver function. This marker is a ratio, and therefore does not have units.

    Measured: 11-16 years post CALERIE trial

  100. Uric Acid

    Uric acid, a blood-based marker of purine metabolism, will be measured in mg/dL.

    Measured: 11-16 years post CALERIE trial

  101. Calcium (Ca)

    Calcium, a blood-based mineral, will be measured in mg/dL.

    Measured: 11-16 years post CALERIE trial

  102. Phosphorus (P)

    Phosphorus, a blood-based mineral, will be measured in mg/dL.

    Measured: 11-16 years post CALERIE trial

  103. Magnesium (Mg)

    Magnesium, a blood-based mineral, will be measured in meq/L.

    Measured: 11-16 years post CALERIE trial

  104. Sodium (Na+)

    Sodium, an electrolyte that reflects the body's fluid balance, will be measured in meq/L.

    Measured: 11-16 years post CALERIE trial

  105. Potassium (K+)

    Potassium, an electrolyte that reflects the body's fluid balance, will be measured in meq/L.

    Measured: 11-16 years post CALERIE trial

  106. Chloride (Cl-)

    Chloride, an electrolyte that reflects the body's fluid balance, will be measured in meq/L.

    Measured: 11-16 years post CALERIE trial

  107. Apoprotein A1

    Apoprotein A1, a blood-based marker of lipid metabolism, will be measured in mg/dL.

    Measured: 11-16 years post CALERIE trial

  108. Apoprotein B

    Apoprotein B, a blood-based marker of lipid metabolism, will be measured in mg/dL.

    Measured: 11-16 years post CALERIE trial

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted15 Dec 2022
  2. Study start6 Apr 2023
  3. Primary completion31 Jan 2027 (estimated)
  4. Study completion31 Jan 2028 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Observational
Observational model
Case-control
Time perspective
Other
Enrolment
216 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05651620
Sponsor's protocol ID
STUDY00002577
Other IDs
1R01AG071717-01A1
Status last verified
Jun 2026
First submitted
1 Sep 2022
Last updated
9 Jun 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Yes: Per the NIH Data Public Access Policy, after study closure, the data coordinating center at Duke University will lock the electronic database and clean and deidentify the data prior to public posting. Biospecimens collected for banking will be deidentified and transferred to the NIA AgingResearchBiobank, which utilizes a state-of-the-art inventory system for the storage and distribution of study samples for future scientific research. The study protocol and informed consent form will be made available as well.

Questions about this trial

What is this clinical trial studying?

An observational study of Calorie Restriction, run by Tufts University at 3 sites 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 2 inclusion and 4 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: under way, not looking for participants, as of the sponsor's last update on 9 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 3 sites 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?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Biological age - Klemera-Doubal Method (time frame: 11-16 years post CALERIE trial). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?
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 9 Jun 2026.

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