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results of the Ranger study. It met in executive sessions on days two and three to review the research results and develop its recommendations.


The Committee reviewed the Ranger assessment data provided by the Army scientists and the material covered during the oral presentations. A summary of the CMNR responses to the five questions posed by USARIEM are provided here.

  1. Was the nutrition intervention (increasing energy provision by 10-15 percent) effective in decreasing medical risk?

    There were several variations in the Ranger II study compared to Ranger I, but the significant intervention variable was the increase of approximately 15 percent in calories, along with additional protein. This change in intake appeared to reduce the severity of the weight loss of the groups and reduced the extremes of weight loss seen in the Ranger I study. A slightly reduced stress on immune function was also noted.

  2. Should an even greater increase in energy intake be recommended (assuming it is consistent with Ranger training goals)?

    Overall, the caloric supplement appeared compatible with Ranger goals. However, the value of additional increases in energy intake requires further study.

  3. Should any specific supplementation of vitamins, minerals, or protein be considered?

    No. Except for zinc, the data do not suggest any problems with regard to vitamin or mineral nutriture. (It was a rare, unusual, and unexplained finding that average plasma zinc concentrations were elevated in the trainees.) The more hypocaloric the state of the individual, the more protein will be required to minimize negative nitrogen balance.

  4. Are the immunological changes noted related to the plane of nutrition during Ranger training or to other (e.g., sleep deprivation) stressors?

    Some are clearly caused by the decreased plane of nutrition. Other concomitant stressors (e.g., loss of sleep and minor infections) could also contribute to the observed immune system derangements.

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