Sports, Exercise, and Health Sciences: Nutrition and Academic Performance

Lillian Geis 3B Extended Essay

Research Question: To what extent does nutrition impact academic performance in preadolescence and adolescence students?

Study I

The first study introduced is titled, “Food Intake and Academic Performance Among Adolescents” which was conducted in 2008. The purpose of this study was to examine the connection between nutrition and various factors, including academic performance. The main author (MacLellan) was the Past-Chair for the Dietitians of Canada which leads a research program that works to understand factors influencing nutrition knowledge and eating behaviors in adolescents and adults. The sample size for this study was 325 students selected from 4 junior high schools in Prince Edward Island. The study measured the intake of fruits, vegetables, and milk in Prince Edward Island to see if there was a heightened academic performance with and elevated intake of these foods. The method that was utilized in this study was a modified survey which the participants completed to measure the daily nutrition they were receiving. The survey was made up of 7 questions that asked the participants about their milk and vegetable intake over the prior 7 days. Factors such as race, sex, and academic performance over the past 12 months (MacLellan 142). The milk and vegetables were measured by the number of servings that were consumed per day. For the vegetables, an average consumption of 5 serving a day was satisfactory. For the milk, an average consumption of 3 servings a day was satisfactory(MacLellan 142).

The above figure is one of the graphs from the survey that displays the results from the survey paired with the academic performance of the junior high students over the past 12 months. The Y-axis illustrates the percentage of students and the X-axis illustrates the various fruits, vegetables, and milk that were measured in the survey. Each of the bars represent the various grades of the students. The researchers separated the grades into three levels, ranging from above 90%, 80–89%, and below 80%(MacLellan 142). On average, the students who consumed the highest amount of vegetables and milk daily performed the best academically. This can be seen in Figure 2 where the students who performed >90% had the highest intake of fruits, vegetables, and milk. On average, the students who performed the worst academically, or <80%, consumed the least fruits, vegetables, and milk daily. There is an exception to this with the salad and carrot bars, where the 80–89% group consumed less than the <80% group. When referring back to Figure 2, the difference between the >90% group and the 80–89% group is greater than the difference between the 80–89% group and the <80% group, which calls for more research to examine if there is a significant difference in high and low consumption of fruits, vegetables, and milk.

From the survey, the researchers form that the daily mean intake of vegetables and fruits was 4.3 ±2.3 servings. They found that the daily mean intake of milk was 1.7 ±1.4 servings. Out of all the participants, only 31% consumed a satisfactory daily amount of fruits and vegetables ad 33% consumed a satisfactory daily amount of fruits (MacLellan 143).

This study aids in reinforcing the idea that nutrition impacts academic performance because the students who consumed on average healthier food (fruit, vegetables, and milk) performed better in school academically. Some weaknesses with this study include the size on the sample. The researchers used 325 participants, but out of this number, only 280 responded, making the response rate 86%. This sample size was too small to reflect towards a whole population, another study would need to be conducted in order to confirm the association that was found. Also, the collection method may contain bias because it was conducted with a survey and self-reflection may contain bias. Some of the strengths of the study include the fact that it was a controlled experiment with controlled variables. The researchers had a select number of variables they were measuring and the end goal of measuring nutrition and academic performance was not lost. There was almost an equal number of males and females (54.4% female, 45.6% male) and 85.4% of the students were between the ages 13–15 with a mean age of 13.7 (Maclellan 142). Also, there was no interviewer bias due to the way that the study was conducted through the use of a survey.

This study is highly relevant because it aids in supporting the necessity for eating healthy foods and has multiple graphs that clearly display the results of the survey. The researchers found that there was a correlation between high academic scores and a higher daily intake of the essential nutrients found in fruits, vegetables, and milk.

Study II

The second study introduced is titled, “Nutritional quality of diet and academic performance in Chilean students” which was conducted from 2009 to 2012. The purpose of this study was to illustrate that the consumption of low quality food, which is ranked in the study, resulted in a lower academic performance. It pulled from a wide range of students from many different socioeconomic backgrounds, educations, and body mass index (BMI). The main author (Burrows) graduated from Institute of Nutrition and Food Technology in the University of Chile. The sample consisted of 395 16 year-old students living in Santiago, Chile (from a region of low-to-middle socioeconomic status) who were part of a companion study beginning in infancy. This study examined the associations between the nutritional quality of diet in children age 16 and academic performance in students from Santiago, Chile. This study was conducted through the use of a survey from 2009–2012 collecting information on saturated fat, fiber, sugar and salt in the food and the average (GPA) and tests for college admission in language and mathematics. The researchers recognised that sociodemographic, educational and body-mass index (BMI) factors could be potential confounders to the study (Burrows 185).

In this survey, there were specific distinctions made on what food was considered healthy or unhealthy. The nutritional quality of diet was assessed by measuring the amount of saturated fat, fiber, sugar and salt in the food. The survey had a list of 110 common food and beverage options in a Chilean household and asked the participants to number how often they consumed each item (0–7 times a week). Prior to sending out the survey, each meal was categorized into groups for further analysis and organization. “Each meal was considered to be: unhealthy (poor nutritional value items, high in fat, sugar, salt and calories); fair (highly processed items although low in fat); or healthy (nutrient rich foods). A score ranging from 0–2 was assigned to each meal category, with higher scores representing healthier habits” (Burrows 186). There were also specific distinctions made about the measurement of the academic performance in the students. The researchers used two indicators to measure the academic performance. The first was using the Chilean national standardized exam for admission into college. This exam is made up of two mandatory tests (language and mathematics), and two non-mandatory tests (science and social science). For the results of the study, the scores that received ≥ 75th percentile in language (521) and mathematics (524) in the sample from the survey were considered good academic performance (highest is 825). The researchers also measured the grade-point average (GPA) of each student to include a lasting measurement of how the students had performed in school.

In the graphs above found that unhealthy diet at age 16 years was associated with reduced academic performance. Compared to participants with healthy diets, those with unhealthy diets were significantly less likely to perform well based on language

This study aids in reinforcing the idea that nutrition impacts academic performance because the students who consumed on average healthier foods in the survey performed better in school academically. A weaknesses with this study would be the collection method used to obtain the information. This method may contain bias because it was conducted with a survey and self-reflection and through this some of the information may be invalid. Some of the strengths of the study include the fact that the researchers took into consideration confounding factors that may have contributed to these higher test scores. These factors include socioeconomic factors, gender, race, etc. and by accounting for these factors, it makes the data more reliable. It discusses the effect of low income houses and how this impacts the nutrition of the household. The study was also conducted over three years. This adds to the validity of the study because the repetition helps to equalize any faulty responses. There was almost an equal number of males and females (52% female, 48% male)(Burrows 187). Also, there was no interviewer bias due to the way that the study was conducted through the use of a survey.

This study is highly relevant because it clearly displays the importance of healthy dishes in relation to test scores and GPA and has multiple graphs that clearly display the results of the survey. The researchers found that there was a correlation between high academic scores and a higher daily intake of the essential nutrients found in everyday typical Chilean dishes.

Works Cited

Correa-Burrows, Paulina, et al. “Nutritional Quality of Diet and Academic Performance in Chilean Students.” World Health Organization.Bulletin of the World Health Organization, vol. 94, no. 3, 2016, pp. 185–192, ProQuest Central; ProQuest Environmental Science Collection,

MacLellan, Debbie,PhD., R.D., Taylor, Jennifer,PhD., R.D., and Kyla Wood B.Sc. “Food Intake and Academic Performance among Adolescents.” Canadian Journal of Dietetic Practice and Research, vol. 69, no. 3, 2008, pp. 141–4, ProQuest Central,