Challenges in defining successful adherence to calorie restriction goals in humans: Results from CALERIE™ 2.

Journal Article (Journal Article)

BACKGROUND: The Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy (CALERIE™) phase 2 trial tested the effects of two years of 25% calorie restriction (CR) on aging in humans. CALERIE 2 was one of the first studies to use a graph of predicted weight loss to: 1) provide a proxy of dietary adherence, and 2) promote dietary adherence. Assuming 25% CR, each participant's weight over time was predicted, with upper and lower bounds around predicted weights. Thus, the resulting weight graph included a zone or range of body weights that reflected adherence to 25% CR, and this was named the zone of adherence. Participants were considered adherent if their weight was in this zone. It is unlikely, however, that the entire zone reflects 25% CR. OBJECTIVES: To determine the level of CR associated with the zone of adherence and if the level of CR achieved by participants was within the zone. METHODS: Percent CR associated with the upper and lower bounds of the zone were determined via the Body Weight Planner ( for participants in the CALERIE 2 CR group (N = 143). Percent CR achieved by participants was estimated with the intake-balance method. RESULTS: At month 24, the zone of adherence ranged from 10.4(0.0)% to 19.4(0.0)% CR [Mean(SEM)], and participants achieved 11.9(0.7)% CR and were in the zone. CONCLUSION: The results highlight the challenges of: 1) setting a single CR goal vs. a range of acceptable values, and 2) obtaining real-time and valid measures of CR adherence to facilitate adherence.

Full Text

Duke Authors

Cited Authors

  • Martin, CK; Höchsmann, C; Dorling, JL; Bhapkar, M; Pieper, CF; Racette, SB; Das, SK; Redman, LM; Kraus, WE; Ravussin, E; CALERIE™ Phase 2 Study Group,

Published Date

  • June 1, 2022

Published In

Volume / Issue

  • 162 /

Start / End Page

  • 111757 -

PubMed ID

  • 35240264

Pubmed Central ID

  • PMC8976757

Electronic International Standard Serial Number (EISSN)

  • 1873-6815

Digital Object Identifier (DOI)

  • 10.1016/j.exger.2022.111757


  • eng

Conference Location

  • England