Chapter 2: Nutritional Assessment of Athletes: Research and Clinical Perspectives

INTRODUCTION

This chapter focuses on the applications, strengths and limitations of the main methods used for conducting a nutrition assessment and in particular assessing dietary intakes in clinical practice and in research, and their relevance to athletes. The chapter identifies the key differences in how diet is assessed in research and clinical practice and outlines how new technologies are improving the assessment of diet.

NUTRITIONAL ASSESSMENT PROCESS

A nutritional assessment of an individual athlete, as well as a medical check-up, a musculoskeletal assessment and a psychological assessment, is now routine in many sporting organisations. For dietitians, the nutritional assessment is the first of four steps in the Nutrition Care Process. The Nutrition Care Process is a structural framework for dietitians to provide nutrition care to patients, clients and groups or communities and is easily adapted for use in athletes (Academy of Nutrition & Dietetics 2018). A nutrition assessment is the basis for the four stages that complete the Nutrition Care Process:

1. nutrition assessment and reassessment

2. nutrition diagnosis

3. nutrition intervention

4. nutrition monitoring and evaluation.

The Academy of Nutrition and Dietetics has developed standards of professional performance as a resource for sports dietitians and includes documentation on specific indicators for nutrition assessment in athletes (Steinmuller et al. 2014).

Dietary assessment (also referred to as the food- and nutrition-related history) is a key component of the nutritional assessment of an individual athlete (see section 2.7). This information may be further supplemented with energy expenditure analysis (in training and competition), physique assessment, biochemical data and health history.

In a healthy athlete, symptoms of lethargy, fatigue, poor performance capacity, poor concentration and slow recovery from a hard training session can be nutrition-related. Increased incidence of injury or infection or large losses in body mass (BM) may also be linked to suboptimal nutrient intake or energy imbalance. Often, inconsistency in performance and during training is a signal for a coach to refer an individual athlete to a dietitian for a nutrition assessment. The domains of nutrition assessment data, also referred to as nutrition indicators, include:

• food- and nutrition-related history

• physique assessment (body composition and anthropometric measurements)

• biochemical data, medical tests and procedures

• nutrition-focused physical findings

• athlete history.

Sports nutrition practice requires skills and knowledge in all these areas and the ability to apply evidence-based research to assist athletes to work towards their performance-related goals (Thomas et al. 2016). A sports dietitian is trained to diagnose nutrition-related problems, taking into account the physiological, medical, social and psychological issues that affect performance and health, and to plan the nutritional intervention, monitoring and evaluation of the athlete accordingly.

The main goals of nutrition assessment, and the first step in the Nutrition Care Process, are to:

• identify athletes who require nutritional ...