InternationalJournal of Sport Nutrition, 1991, 1,395-407
Seasonal Changes in Female Athletes' Diets June Nutter Wake Forest University Dietary intakes of 24 female athletes in various sports were compared inseason and postseason to those reported by 24 nonathletes during the same time period. Diets were analyzed for energy, carbohydrate, fat, protein, vitamins A and C, thiamin, riboflavin, niacin, folacin, calcium, and iron. During the study, the athletes' and nonathletes' diets were similar. Their energy intakes were lower than recommended while their iron and calcium intakes were marginal (less than 70% of the recommended dietary allowance). Although few dietary changes were observed, the nonathletes' diets changed more than those of the athletes during the study. Both groups reduced their energy intakes but only the nonathletes' reduction was significant. Initially many subjects were dieting. More subjects reported dieting during the second recording period. These results suggest that the desire to be thin may influence dietary intakes of female athletes more than changes in exercise training. Good nutrition is important in developing and maintaining athletic performance (7). With greater numbers of women participating in competitive sports, there has been an increased interest in the diet of the female athlete (1, 5, 10, 13, 14, 15, 16). It has generally been assumed that athletes increase their food consumption to meet the increased demand for energy imposed by increased physical activity, thus eating a nutritionally adequate diet. However, results of recent studies (5, 10, 15) suggest that many female athletes consume less than the recommended dietary allowance (RDA) for energy intake (7). Because low energy intake may result in a less than desirable intake of nutrients that are important for both health and athletic performance, nutritional inadequacy during competitive training would presumably have a detrimental effect on performance. 1 Previous investigations of female athletes' diets~whichhave typically been conducted preseason, have not been well controlled (13) or have compared the diets to data from large epidemiological studies (5, 10) that may have used different methods of data collection and analysis. There are little data comparing the dietary intake of similar noncompetitive populations with that of female athletes
June Nutter, who was with the Dept. of Health and Sport Science at Wake Forest University at the time of this study, is now with the Dept. of Health, Physical Education, Recreation and Dance at Rhode Island College, Providence, RI 02908.
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during the competitive season (14) when diet is likely to have a more direct influence on competitive performance. Given the increased energy demands of training and competition, it might be expected that the diet of female athletes differs inseason compared to postseason. Female athletes may limit their dietary intake to keep their body weight low to improve athleticperformance during their competitive season and increade their intake during the postseason. However, seasonal changes in dietary intakes of female athletes have not been studied. The purpose of this study was to compare the dietary intake of female college athletes during the competitive season with their dietary intake postseason. A secondary purpose of the study was to compare the athletes' diet with that of nonathlete female subjects during the same time period.
Methods and Materials Twenty-four female varsity athletes at a private liberal arts university volunteered as subjects. Nine were field hockey players, 6 were cross-country runners, 4 played tennis, and 5 were golfers. In addition, 24 female students who did not participate on an intercollegiate athletic team were randomly selected from the student directory to serve as a,control group. The athletes, were not given a training table for their meals. Informed consent was obtained prior to participation in the study. Subjects recorded the amounts of all foods and beverages ingested for 7 days. They were instructed in the use of the dietary recording forms prior to participation in the study. Food models and measuring spoons were used to help them estimate serving sizes. Subjects were also given written instructions prior to the recording period. These instructions reminded them to record the amounts of all foods and beverages, including water and alcohol, and any food or vitamin1 mineral supplements (including brand names if possible) as soon as possible after eating. Appropriate serving sizes were also described in the written instructions. A completed sample recording sheet was also provided to the subjects to improve accuracy of recurding data. The athletes recorded their food intake approximately midway through their competitive season and 2 weeks after their season ended (approximately 6 weeks later). The nonathletes recorded their food intake during the same time period. Three representative days were chosen for analysis since some diets changed due to illness or other factors such as birthday celebrations. For the athletes, the 3 days that were analyzed included a weekend day, a practice day, and a competition day. For the nonathletes, the 3 days selected for analysis included-a weekend day and 2'weekdays. Vitamin, mineral, and other supplements were recorded but were not included in the diet analysis. Information concerning weight loss was obtained by survey. A c~mputer~diet analysis program (Nutritionist 11; N Squared Computing, Salem, OR) was used to analyze the diet records for ener&, carbohydrate, fat, protein, vitamins A and C , thiamin, riboflavin, niacin, folacin, calcium, and iron. Nutrient and energy content of foods andlor beverages which were not included in the expanded data base of the computer program were determined from nutritive analyses of foods (9).and added to the computer analysis. The program also compared the total of,each nutrient with the RDA (7). Analysis of variance (Groups x Time) for repeated measures with Tukey post hoc comparisons was used to analyze the data (8). Statistical significance was accepted at thepG0.05 level.
Seasonal Changes in Athletes' Diets 1 397
Table 1 Descriptive Characteristics of the Subjects lnseason and Postseason Age (Yrs)
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Weight (kg) Inseason Postseason M SD M SD
M
SD
M
SD
18.7
1.2
163.3
5.8
63.5
6.2
63.8
5.5
20.4
0.6
165.0
3.7
60.9
6.3
62.1
6.1
18.8
0.8
164.6
3.8
51.9
1.gbvcvd
52.7
2.0~
Group Field hockey (n=9) Golf (n=5) Cross-country (n=6) Tennis (*4)
Height (crn)
a~ignificantdifferenceinseasonto postseason, pc0.05; bsignificantlydifferentthan nonathletes, pc0.01 ;'significantly differentthangolf, pc0.01 ;dsignificantlydifferentthanfieldhockey, pc0.01.
Results Descriptive Characteristics
Descriptive data of the subjects are presented in Table 1. The cross-country runners and tennis players weighed significantly less than the nonathletes, golfers, and field hockey players (p
Seasonal Changes in Female Athletes' Diets June Nutter Wake Forest University Dietary intakes of 24 female athletes in various sports were compared inseason and postseason to those reported by 24 nonathletes during the same time period. Diets were analyzed for energy, carbohydrate, fat, protein, vitamins A and C, thiamin, riboflavin, niacin, folacin, calcium, and iron. During the study, the athletes' and nonathletes' diets were similar. Their energy intakes were lower than recommended while their iron and calcium intakes were marginal (less than 70% of the recommended dietary allowance). Although few dietary changes were observed, the nonathletes' diets changed more than those of the athletes during the study. Both groups reduced their energy intakes but only the nonathletes' reduction was significant. Initially many subjects were dieting. More subjects reported dieting during the second recording period. These results suggest that the desire to be thin may influence dietary intakes of female athletes more than changes in exercise training. Good nutrition is important in developing and maintaining athletic performance (7). With greater numbers of women participating in competitive sports, there has been an increased interest in the diet of the female athlete (1, 5, 10, 13, 14, 15, 16). It has generally been assumed that athletes increase their food consumption to meet the increased demand for energy imposed by increased physical activity, thus eating a nutritionally adequate diet. However, results of recent studies (5, 10, 15) suggest that many female athletes consume less than the recommended dietary allowance (RDA) for energy intake (7). Because low energy intake may result in a less than desirable intake of nutrients that are important for both health and athletic performance, nutritional inadequacy during competitive training would presumably have a detrimental effect on performance. 1 Previous investigations of female athletes' diets~whichhave typically been conducted preseason, have not been well controlled (13) or have compared the diets to data from large epidemiological studies (5, 10) that may have used different methods of data collection and analysis. There are little data comparing the dietary intake of similar noncompetitive populations with that of female athletes
June Nutter, who was with the Dept. of Health and Sport Science at Wake Forest University at the time of this study, is now with the Dept. of Health, Physical Education, Recreation and Dance at Rhode Island College, Providence, RI 02908.
Downloaded by New York University on 09/16/16, Volume 1, Article Number 4
during the competitive season (14) when diet is likely to have a more direct influence on competitive performance. Given the increased energy demands of training and competition, it might be expected that the diet of female athletes differs inseason compared to postseason. Female athletes may limit their dietary intake to keep their body weight low to improve athleticperformance during their competitive season and increade their intake during the postseason. However, seasonal changes in dietary intakes of female athletes have not been studied. The purpose of this study was to compare the dietary intake of female college athletes during the competitive season with their dietary intake postseason. A secondary purpose of the study was to compare the athletes' diet with that of nonathlete female subjects during the same time period.
Methods and Materials Twenty-four female varsity athletes at a private liberal arts university volunteered as subjects. Nine were field hockey players, 6 were cross-country runners, 4 played tennis, and 5 were golfers. In addition, 24 female students who did not participate on an intercollegiate athletic team were randomly selected from the student directory to serve as a,control group. The athletes, were not given a training table for their meals. Informed consent was obtained prior to participation in the study. Subjects recorded the amounts of all foods and beverages ingested for 7 days. They were instructed in the use of the dietary recording forms prior to participation in the study. Food models and measuring spoons were used to help them estimate serving sizes. Subjects were also given written instructions prior to the recording period. These instructions reminded them to record the amounts of all foods and beverages, including water and alcohol, and any food or vitamin1 mineral supplements (including brand names if possible) as soon as possible after eating. Appropriate serving sizes were also described in the written instructions. A completed sample recording sheet was also provided to the subjects to improve accuracy of recurding data. The athletes recorded their food intake approximately midway through their competitive season and 2 weeks after their season ended (approximately 6 weeks later). The nonathletes recorded their food intake during the same time period. Three representative days were chosen for analysis since some diets changed due to illness or other factors such as birthday celebrations. For the athletes, the 3 days that were analyzed included a weekend day, a practice day, and a competition day. For the nonathletes, the 3 days selected for analysis included-a weekend day and 2'weekdays. Vitamin, mineral, and other supplements were recorded but were not included in the diet analysis. Information concerning weight loss was obtained by survey. A c~mputer~diet analysis program (Nutritionist 11; N Squared Computing, Salem, OR) was used to analyze the diet records for ener&, carbohydrate, fat, protein, vitamins A and C , thiamin, riboflavin, niacin, folacin, calcium, and iron. Nutrient and energy content of foods andlor beverages which were not included in the expanded data base of the computer program were determined from nutritive analyses of foods (9).and added to the computer analysis. The program also compared the total of,each nutrient with the RDA (7). Analysis of variance (Groups x Time) for repeated measures with Tukey post hoc comparisons was used to analyze the data (8). Statistical significance was accepted at thepG0.05 level.
Seasonal Changes in Athletes' Diets 1 397
Table 1 Descriptive Characteristics of the Subjects lnseason and Postseason Age (Yrs)
Downloaded by New York University on 09/16/16, Volume 1, Article Number 4
Weight (kg) Inseason Postseason M SD M SD
M
SD
M
SD
18.7
1.2
163.3
5.8
63.5
6.2
63.8
5.5
20.4
0.6
165.0
3.7
60.9
6.3
62.1
6.1
18.8
0.8
164.6
3.8
51.9
1.gbvcvd
52.7
2.0~
Group Field hockey (n=9) Golf (n=5) Cross-country (n=6) Tennis (*4)
Height (crn)
a~ignificantdifferenceinseasonto postseason, pc0.05; bsignificantlydifferentthan nonathletes, pc0.01 ;'significantly differentthangolf, pc0.01 ;dsignificantlydifferentthanfieldhockey, pc0.01.
Results Descriptive Characteristics
Descriptive data of the subjects are presented in Table 1. The cross-country runners and tennis players weighed significantly less than the nonathletes, golfers, and field hockey players (p
