Purpose of reviewEvaluation of an athlete's diet is important in both clinical practice and research. The main purpose of this review is to provide health professionals with guidance regarding the special issues that are likely to be encountered when assessing the dietary intake of sportspersons.Rec

Methodology of dietary assessment in athletes: concepts and pitfalls.

Purpose: The correct assessment of energy expenditure (EE) in athletes is important to ensure that dietary energy intake is sufficient. In general, athletes are individuals with especially high levels of total EE (TEE) and exercise-related EE (ExEE). The SenseWear Pro3 Armband (SWA) is a multisensor device for the individual assessment of EE, but data on the validity for higher exercise intensities are missing. The aim of the study was to validate the SWA for the assessment of TEE and ExEE in endurance athletes.

Methods: The SWA was worn by 14 male endurance athletes for 7 d during a regular training period, and TEE was measured in parallel with the doubly labeled water method. Two controlled exercise trials (treadmill running = 2.4-4.8 m·s-1, stationary bicycling = 140-380 W) were performed, during which indirect calorimetry was used to assess ExEE.

Results: TEE assessed with the SWA and TEE measured with the doubly labeled water method were significantly correlated (r = 0.73, P < 0.01), but there were a proportional bias and considerably wide limits of agreement (-1368 to 1238 kcal·d-1). The error of TEE assessed with the SWA was related to the athletes' individual lactate thresholds (P < 0.05). During running and bicycling, ExEE was significantly underestimated for most exercise intensities, and the underestimation increased with exercise intensity (P < 0.001).

Conclusions: According to our results, the SWA does not provide valid results of TEE and ExEE in endurance athletes because of the underestimation of EE at higher exercise intensities. It seems necessary to develop exercise-specific prediction equations to improve EE measurements in athletes

Assessing energy expenditure in male endurance athletes: validity of the SenseWear Armband.

To investigate whether aquatic athletes follow optimal dietary intake, 58 athletes, all members of the Greek national swimming and water polo teams, were tested. Dietary intake was assessed at the nutrient, food, and food group level using the 24-h recall method and a food frequency questionnaire. Mean energy intake for males and females was 14.3 and 8.5 MJ, respectively. Mean carbohydrate consumption for male and female athletes was 4.5 g/kg and 3.8 g/kg of body weight, respectively. Fat intake was 153 g for males and 79 g for females. A significant number of the athletes (71% of the males, 93% of the females) did not meet the Dietary Reference Intakes for at least one of the antioxidant vitamins. The data suggest that athletes of both genders consumed too much fat and too little carbohydrate. Insufficient fruit and vegetable intake was related to low intake of antioxidants.

Dietary Intake and Nutritional Practicesof Elite Greek Aquatic Athletes

Previous intervention studies suggest that leptin, insulin, insulin-like growth factor 1 (IGF-1), and triiodthyronine (T3) are sensitive markers of inadequate energy intake in relation to exercise expenditures. Because of limitations in metabolic hormone measurements, self-reported energy availability (EA) based on food and activity records may present an alternative for characterizing energy status in young athletes. The purpose of the current study was to assess whether self-reported EA is related to leptin, insulin, IGF-1, and T3 in 352 young athletes. Sex, body composition, sport participation, and acute weight changes were considered as confounding variables. Multiple linear regression revealed that EA was negatively associated with leptin (p 1 kg·week(-1)) had a lower EA (18.9 ± 7.4 kcal·kg(-1) FFM) than did weight-stable athletes (30.0 ± 11.2 kcal·kg(-1) FFM) or athletes reporting weight gain (>1 kg; 49.7 ± 13.1 kcal·kg(-1) FFM). IGF-1 and T3 were also reduced in athletes who lost weight (p < 0.01). This cross-sectional study reveals a lack of association between self-reported EA and metabolic hormones indicative of energy status in young athletes. Further studies are needed to investigate whether self-reported EA and metabolic hormones are in better agreement when measured repeatedly.

Comparison of self-reported energy availability and metabolic hormones to assess adequacy of dietary energy intake in young elite athletes.

Dietary intake and nutritional practices of elite Greek aquatic athletes.

Summary The different techniques for assessing energy and nutrient intakes are described. Work showing that energy intake is frequently underestimated is summarised. The validity of reported energy intake can be evaluated by comparing reported intake with expected energy expenditure. To do this, information on activity patterns must also be obtained.

Alison E. Black

Papers

Dietary assessment for sports dietetics.