Research On The Effect Of Nutrition Survey And Nutrition Guidance On Adolescent Swimmers

Objective:The nutritional status of adolescent athletes is the basis of affecting their growth and physical health,and also an important guarantee for improving their athletic ability.Adolescent athletes are troubled by education,training security and dietary nutrition problems,and their nutritional status is not satisfactory.Therefore,the purpose of this study is to further investigate the dietary nutrition status of adolescent swimmers and explore the effect of nutritional guidance on the nutritional level of young swimmers.Methods:The experiment is divided into two parts.In the first part,55 young swimmers were investigated by dietary survey,questionnaire survey and biochemical test.All data were collected and analyzed.In the second part,the athletes were randomly divided into the control group and the experimental group.The experimental group was given nutritional guidance for three months,and the control group had no intervention.After the intervention,dietary survey and blood biochemical indexes were conducted again in the experimental group and the control group.Results:1.The results of dietary survey:?1?Total calorie intake and three major nutrients intake:the total calorie intake of adolescent male and female swimmers was 2544±392 kcal and 2111±372 kcal,respectively,with significant difference?p<0.05?.The carbohydrate intake of male and female swimmers was 309±53 kcal and 265±60 kcal,accounting for 48.6%and50.2%of total heat energy,respectively.There was no significant difference between them?p>0.05?.The carbohydrate intake of male athletes is less than 50%of the total caloric energy,while that of female athletes only reaches the lower limit of the recommended range;The protein intake of male and female athletes was 117±29 kcal and 91±28kcal,accounting for 18.4%and 17.3%of total heat energy respectively.The protein intake of male athletes was significantly higher than that of female athletes?p<0.05?.The protein intake of all athletes was within the recommended range;The fat intake of male and female athletes was 93±29 kcal and 76±19 kcal,accounting for33%and 32.5%of the total heat energy,respectively.There was no significant difference between male and female athletes?p>0.05?,the fat intake of all athletes was higher than the recommended range.?2?Breakfast calories of adolescent male and female swimmers were 689±157 kcal and 580±201 kcal,accounting for 27.1%and 27.3%of the total calories,respectively.The breakfast calories of male athletes were significantly higher than that of female athletes?p<0.05?,and the breakfast calories of all athletes were within the recommended range;Lunch calories of adolescent male and female swimmers were819±166 kcal and 638±125 kcal,accounting for 32.2%and 30.1%of the total calorie,respectively,the lunch calories of male athletes were significantly higher than that of female athletes?p<0.05?,the calorie intake of some athletes only reaches the lower limit of recommended range,some athletes have insufficient energy intake for lunch,which is less than 30%of the total calorie in a day;Dinner calories of adolescent male and female swimmers were 923±206 kcal and 763±212 kcal,accounting for36.4%and 35.3%of the total calories,respectively,over 35%of total calorie intake per day.Calorie intake at dinner for all athletes,all exceeded the recommended range;The calorie intake of adolescent male and female athletes at dinner was significantly higher than that at lunch?p<0.05?;The extra meal calorie intake of adolescent male and female athletes was 112±20 kcal and 154±23 kcal,accounting for 4.4%and 7.3%of the total calorie,respectively.The extra meal calorie intake of female athletes was significantly higher than that of male athletes?p<0.05?.2.Questionnaire results:?1?Basic information:81%of the athletes have attended relevant nutrition courses and lectures,but 76%of the athletes still do not understand the"Dietary Guidelines for Chinese Residents",34%of the athletes are not satisfied with their body shape.?2?Nutrition attitude:60%of athletes pay more attention to diet and nutrition,49%of them think diet and nutrition are very important to their health,58%of them think diet and nutrition are very important to sports training,73%of them are willing to restrict themselves to a scientific diet.?3?Nutrition attitude:Only 29%of athletes picked the right answer about the main substance that provides energy during exercise:sugar;As for the main food source of protein,76%of the athletes chose the right answer:meat;About the fat content of food,47%of the athletes chose the right answer:fish;About the best source of vitamin C,only 49%of athletes chose the right answer:fresh vegetables and fruits;About which foods contained the most calcium,51%of the athletes chose the right answers:dairy products and soybean products.?4?Dietary behavior:19%of the athletes occasionally and often do not eat breakfast;13%of the athletes often and daily snacks instead of dinner;69%of the athletes have the habit of eating regular midnight snack;More than 50%of the athletes eat vegetables,fruits and milk regularly and daily;73%of the athletes occasionally and often take nutrients;Athletes who ate three meals irregularly or indefinitely accounted for 42%;Only 58%of the athletes paid attention to food collocation in their daily diet.3.Results of blood biochemical indicators:?1?Nutritional status of protein:The contents of hemoglobin,total protein,albumin and globulin of male and female adolescent swimmers are in normal range.?2?Nutritional status of inorganic salts:The contents of lead,copper,zinc,calcium,magnesium and iron in male and female adolescent swimmers are in normal range.?3?The nutritional status of vitamins:The concentration of vitamin A of male and female adolescent swimmers is within the normal range.Tthe concentration of serum25-OHD₃ of male and female adolescent swimmers is 42.01±8.35nmol/L and36.52±9.31nmol/L respectively,vitamin D levels of all athletes were not adequate.4.Changes of nutritional level before and after intervention:Compared with before intervention,carbohydrate intake in the experimental group increased significantly?p<0.05?,and the carbohydrate energy supply ratio of male and female athletes reached the recommended range;Compared with before intervention,the fat intake of male and female athletes decreased significantly?p<0.05?,and the fat energy supply ratio reached the recommended range;Compared with before intervention,the calorie intake of breakfast and lunch of male and female athletes increased,but there was no significant difference?p>0.05?,while the calorie intake of dinner decreased significantly?p<0.05?;Compared with before intervention,the calories intake of extra meal in the experimental group increased significantly?p<0.05?;Compared with before intervention,there was no significant difference in the three nutrients and calorie intake of three meals in the control group?p>0.05?;Compared with before intervention,the serum 25-OHD₃ concentration in the experimental group increased significantly?p<0.05?,while the serum 25-OHD₃concentration in the control group decreased significantly?p<0.05?.Conclusion:1.The proportion of carbohydrate intake in the total calories of adolescent swimmers is relatively low,while the proportion of fat intake in the total calories is relatively high.Compared with the caloric intake of breakfast and lunch,the caloric intake of dinner is relatively high and exceeds the recommended range of the caloric intake of dinner.2.Adolescent swimmers lack nutritional knowledge,dietary behavior and scientific dietary self-management awareness.3.The serum 25-OHD₃ concentration of all athletes was lower than 75 nmol/L,and there were deficiencies of vitamin D and different degrees of deficiency.4.To a certain extent,nutrition guidance can promote athletes to have more balanced intake of the three nutrients and more reasonable distribution of energy in three meals;Nutritional guidance can improve the nutritional level of athletes'serum 25-OHD₃ to a certain extent,but the impact is limited.For athletes with vitamin D deficiency,it is difficult to achieve adequate serum 25-OHD₃ level through a single diet control.