Nutrition and Athletic Performance

Nancy R. Rodriguez, PhD, RD, CSSD, FACSM; Nancy M. DiMarco, PhD, RD, CSSD, FACSM; Susie Langley, MS, RD, CSSD


March 01, 2010

In This Article

Evidence-based Analysis

Studies used in the development of this position paper were identified from the PubMed database maintained by the National Library of Medicine and CENTRAL database, as well as through research articles and literature reviews. Five topic-specific questions were identified for evidence-based analysis (Fig. 1) and incorporated into this position, updating the prior position on nutrition and performance.[1] Search terms used were athlete, performance, power, strength, endurance, or competition and macronutrient, meal, carbohydrate, fat, protein, or energy. For the purpose of this analysis, inclusion criteria were adults aged 18-40 yr; all sport settings; and trained athletes, athletes in training, or individuals regularly exercising. Because the grading system used provides allowances for consideration of study design, the evidence-based analysis was not limited to randomized controlled trials. Study design preferences were randomized controlled trials or clinical controlled studies; large nonrandomized observational studies; and cohort, case-control studies. All sample sizes were included and study dropout rate could not exceed 20%. The publication range for the evidence-based analysis spanned 1995-2006. If an author was included in more than one review article or primary research articles that were similar in content, the most recent paper was accepted, and earlier versions were rejected. However, when an author was included in more than one review article or primary research article for which content differed, then both reviews could be accepted for analysis.

Figure 1.

Specific topics and the respective questions used for the evidence analysis sections of the nutrition and athletic performance project.

The following exclusion criteria were applied to all identified studies:

  • Adults older than 40 yr, adults younger than 18 yr, infants, children, and adolescents

  • Settings not related to sports

  • Nonathletes

  • Critical illness and other diseases and conditions

  • Drop out rates >20%

  • Publication before 1995

  • Studies by same author, which were similar in content

  • Articles not in English

Conclusion statements were formulated summarizing the strength of evidence with respect to each question (Fig. 1). The strength of the evidence was graded using the following elements: quality, consistency across studies, quantity, and generalizability. A more detailed description of the methodology used for this evidence-based analysis may be found on the American Dietetic Association's Web site at


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