The Foundation for the National Institutes of Health (FNIH) Sarcopenia Project aimed to develop clinically relevant criteria for diagnosing sarcopenia, a condition characterized by low muscle mass and weakness in older adults. The project utilized data from nine community-based studies involving 26,625 participants (57% women, mean age 75.2 years for men and 78.6 years for women). Key findings included: 1. **Grip Strength**: The final recommended cutpoints for weakness are grip strength <26 kg for men and <16 kg for women. 2. **Lean Mass**: The final recommended cutpoints for low lean mass are appendicular lean mass adjusted for body mass index <0.789 for men and <0.512 for women. 3. **Conference Recommendations**: Feedback from a conference in May 2012 guided additional analyses and refined the criteria. Recommendations emphasized the importance of evaluating the influence of body mass on cutpoints and the need to compare the FNIH criteria with other proposed definitions. 4. **Clinical Relevance**: The criteria are based on mobility impairment as a clinically relevant functional state and are intended to help identify participants for clinical trials and guide interventions. The project's comprehensive data set and large, diverse sample size provide robust evidence for the proposed criteria, which are expected to aid in the development of diagnostic criteria and clinical treatments for sarcopenia.The Foundation for the National Institutes of Health (FNIH) Sarcopenia Project aimed to develop clinically relevant criteria for diagnosing sarcopenia, a condition characterized by low muscle mass and weakness in older adults. The project utilized data from nine community-based studies involving 26,625 participants (57% women, mean age 75.2 years for men and 78.6 years for women). Key findings included: 1. **Grip Strength**: The final recommended cutpoints for weakness are grip strength <26 kg for men and <16 kg for women. 2. **Lean Mass**: The final recommended cutpoints for low lean mass are appendicular lean mass adjusted for body mass index <0.789 for men and <0.512 for women. 3. **Conference Recommendations**: Feedback from a conference in May 2012 guided additional analyses and refined the criteria. Recommendations emphasized the importance of evaluating the influence of body mass on cutpoints and the need to compare the FNIH criteria with other proposed definitions. 4. **Clinical Relevance**: The criteria are based on mobility impairment as a clinically relevant functional state and are intended to help identify participants for clinical trials and guide interventions. The project's comprehensive data set and large, diverse sample size provide robust evidence for the proposed criteria, which are expected to aid in the development of diagnostic criteria and clinical treatments for sarcopenia.