Energy and macronutrient intake in adolescent sprint athletes: A follow-up study


Journal Title (Medline/Pubmed accepted abbreviation): Inl. J. Sport Nutr. Exerc. Metab.
Year: 2011
Volume: 2
Page numbers: 282-290
doi (if applicable):

Summary of Background and Research Design

Background:Young athletes require nutrients for growth as well as energy to fuel athletic performance. Sprinters, specifically, require the ability to generate high amounts of force for a short time period during their event and their nutrition can be tailored to optimize their performance. In general, adolescents consume more fat and less carbohydrates than is recommended. It has been noted that adolescent athletes often do not consume adequate calories and nutrients.

Research Question: What are the dietary habits of adolescent sprinters in Belgium? How does it change during the year? Can habits be improved with non-stringent advice?

Subjects:60 adolescent athletes, age 12-18 yrs old, male (31) and female (29).

Experimental design:One single cohort, no control

Treatments/Protocol:7-day food records were obtained in the summer and winter of 3 consecutive years. They reported all foods and beverages with portion sizes, absolute weights if possible. Energy requirements were estimated with anthropometric and activity measurements and data from athletes who likely under-reported dietary intake were not included in analysis. After analysis, general advice was provided to the athletes including appropriate macronutrient and fluid intake, replacement of refined foods with whole grains, and increasing intake of fruits and vegetables, when applicable.

Summary of research findings:
  • Both boys and girls increased in height and weight over the course of the 3 years, though body fat stayed consistent.
  • There was no significant change in macronutrient intake over the 3 years. In general, protein intake was adequate for > 95% of the athletes. Carbohydrate consumption was adequate for about half of the athletes; there were more girls who did not meet recommendations than boys. As time passed, the percentage of boys and girls who consumed less than 30% of their energy intake from fat increased from 21% to 56% of girls and 42% to 55% of boys. Most dramatic changes were observed the first year. There was also an increase in the number of athletes who consumed less than 10% of their energy from saturated fat in the second and third year compared to year 1. However, the number of athletes that consumed less than 10% of energy from saturated fat was about 1/3 or less.
  • Girls consumed more fiber during years 2 and 3 than in year 1 while there was no observed difference in boys’ intake of fiber with time.
  • A slight increase in vegetable intake was observed as the study progressed, particularly with the boys. Overall, vegetable intake was insufficient compared with recommendations.

Interpretation of findings/Key practice applications:

Athletes’ habits tend to remain consistent throughout the year as well as from year to year. Adolescents could probably benefit from an increase in the healthfulness of their diets, as many did not meet basic dietary recommendations. Subtle feedback and encouragement can improve their diet, so it is expected that more frequent encouragement and education on its importance could further improve the diet of teenagers.

Limitations:

The authors used t-tests for post-hoc analyses of statistical significances after their ANOVA analysis. This approach increases the potential for inflation of type I error rates due to repeated significance testing. Use of a multiple comparisons procedure or a Bonferroni correction can help to manage this problem.
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