Fast Food and Obesity: A Study in a Local McDonald’s

How the fast food revolution established obesity as a primary concern in America.

by Iliana Nguyen | staff writer | SQ Vol. 9 (2011-2012)


After smoking, obesity is the leading cause of mortality in the United States. This does not come as a surprise since obesity rates are higher than ever, with a staggering 33.8% of adults who are obese. Obesity statistics for children living in the U.S. are alarming as well, with approximately 17% (or 12.5 million) of children and adolescents ages 2 to 19 years characterized as obese. Obesity is determined through BMI (body mass index), a number that is calculated based on a person’s weight and height.

Childhood obesity is a serious issue because children who are obese are predisposed to have many health problems and diseases in their childhood and adulthood. Although many factors can contribute to obesity, the underlying cause of excessive weight gain is an imbalance of energy. This occurs when more calories are taken in through diet than expended through energy-consuming activities.

Kerri N. Boutelle, Ph.D., an Associate Professor of Pediatrics and Psychiatry at the University of California, San Diego, conducted a study to evaluate the nutritional quality of fast food purchased for children as well as the reasons for dining at the fast food restaurant.

Dr. Boutelle, who studies childhood obesity and nutrition, explains why she chose to concentrate on youth, stating, “One out of every three children is either overweight or obese. We focus on children because the majority of overweight children will become overweight adults, and we have an opportunity to intervene with children earlier.”

This is the first study published to evaluate the purchasing patterns of fast food for youth. Dr. Boutelle explains, “We were interested in studying fast food purchasing for families because it influences how children eat. We believe that educating parents may influence how they feed their children.”

The number of meals eaten away from home is believed to contribute to extra calorie consumption. Overweight children and adolescents consume more foods away from home compared to other children. Due to its low nutritional value, cheap cost, and large portion size, fast food and consequent consumption habits has been considered one of the factors contributing to the obesity epidemic. Since its introduction to the United States, fast food has risen in popularity to become a prominent role-player in the everyday diet of children. According to studies, about 30% of children report consuming fast food on a typical day.

The Study

Over the course of six weeks, 544 families were surveyed during lunch time at the McDonald’s located in the Rady’s Children Hospital in San Diego, California. Researchers approached families with children who looked between the ages of 2 and 18 years.

The families were asked to present their receipts and to complete a short survey after purchasing their food. Families were asked questions to explain their purchases: who each item was for, if items were shared, sizes ordered (small, medium, large), whether drinks were diet or regular, the type of combination meal purchased, if condiments were added, and lastly, if there were any changes made to their order. The age and gender of the person for whom the item was purchased as well as the reasons for dining at the McDonald’s were inquired about.

Answer choices included: convenience, cheap, adults liked the food, children liked the food, a reward for a hospital visit, hungry with no other options, kids wanted the toy, and that it is a usual place for lunch.


To analyze the data, children were divided into three groups based on their ages: 2 to 5 years old, 6 to 11 years old, and 12 to 18 years old. Researchers then determined the nutritional content of the meals purchased for the different age groups as well as how the meals relate to daily nutrition requirements.

On average, these meals contained a calorie count of 646 to 811 calories, which is 36% to 51% of the recommended daily calorie intake for youth. The children’s meals were found to be extremely high in sodium, with 866 to 1100 mg of sodium consumed per child.

Most popular foods purchased for youth were French fries, soda, chicken nuggets, cheeseburgers, and hamburgers. A Happy Meal was purchased by a little more than half (53%) of the 490 youth. While McDonald’s does offer healthier options such as apple dippers, these choices were found to be less popular. The fruit and yogurt parfait, a heart-friendly option, demonstrated to be very unpopular, only purchased by 1.4% of the families. The top reasons for dining at McDonald’s were convenience and that the children enjoyed the food. About 50% of the families used fast food to reward their children for visiting the hospital. Surprisingly, 72% of adults reported that they liked eating the fast food.

Even though this study was conducted at one fast food location, Dr. Boutelle states, “I don’t think the results would have changed in other locations. What may have changed is what kinds of families participated in the study. We had a wide range of families in this study, so I think it applies to a wide variety of families.”


Childhood obesity is a life threatening condition because it significantly increases the chances of developing many health problems such as type 2 diabetes, stroke, heart attack, hypertension (high blood pressure), and various cancers. Childhood obesity may also lead to social, behavioral, and emotional problems. Obese children may suffer from low self-esteem, depression, and difficulty interacting with peers.

Not only do children need to be aware of what they put in their mouths, but college students need to maintain healthy food habits as well. Dr. Boutelle explains, “College students are at an increased risk for weight gain because it is the first time they are on their own and they get to make all the decisions regarding their food intake. There are many cues in the college environment to overeat, and it is very important for college students to understand the impact of calories from fast food or other sources on their weight.”

Many college students are no stranger to the dreaded “freshman fifteen” pounds gained during their first year of college from unhealthy eating habits. College students are free to eat whenever and whatever they want, even if this means devouring a tub of Ben & Jerry’s on a stressful day.

Also, a majority of college campuses are located near or contain a fast food restaurant where students can buy food at a low cost. Many of these fast food chains are open during late hours, which is perfect for the student that has a midnight craving. Fast food is also ideal for the penny pinching college student who is always on the go–quick food at an affordable cost.

However, college students need to be conscious of what they are putting in their mouths; what is best for their wallet is not necessary the best for their health, especially if it is a Big Mac which is high in sodium, high in calories, and has a low nutritional value. According to a study published in Pediatrics Journal, youth who consume fast food on a typical day consumed greater amounts of saturated fat, sodium, carbohydrate, and sugars and less dietary fiber than those who do not eat fast food.

Consuming fast food also reduces the amount of healthy food options eaten. Children who consume fast food tend to consume more sugar beverages and less milk, as well as fewer fruits and vegetables containing starch. Fruits and non-starchy vegetables are an important part of the daily diet because they contain low energy density and high fiber content, which may protect against excess weight gain. Fiber also plays a major factor in regulating digestion as well as preventing heart disease and colon cancer.

Consuming more than the recommended amount of sodium results in elevated blood pressure, which can increase the risk of many health problems. Blood pressure is the pressure of blood exerted against the walls of the arteries as the heart pumps blood. When the body ingests sodium, this raises osmolarity (the measure of the amount of solutes in a solution) because the concentration of sodium has increased while the volume of fluid in the body remains the same. Vasopressin is secreted, which causes the kidneys to absorb water and increases the blood volume. This causes an increase in blood pressure since the heart has to work harder to push the increased blood volume throughout the body. High blood pressure results in the heart exerting a greater pressure upon the arteries, causing them to stretch and expand to allow blood to flow easier. Overstretching creates weak spots in the artery walls, causing them to become more prone to ruptures, which may possibly lead to a stroke or an aneurysm.

Also, congestive heart failure occurs when the heart muscle becomes worn out from working too hard to pump blood and, as a result, can no longer efficiently pump blood. Fast foods are high in cholesterol as well. Atherosclerosis occurs when the coronary arteries become harder and thicker from a buildup of plaque and cholesterol. This buildup causes blood flow to become severely reduced or completely cut off. If portions of plaque disperse into the bloodstream, oxygen transport to the brain and heart can be disrupted, potentially resulting in a stroke or heart attack. Trans-fats escalate the risk of developing heart disease by increasing LDL cholesterol while lowering HDL cholesterol levels. LDL, known as “bad cholesterol,” is responsible for plaque build-up in arteries. HDL cholesterol, or “good cholesterol,” travels through the bloodstream and removes LDL.

Eating large portions of energy-dense foods also play a factor in the obesity epidemic. Fast food restaurants are notorious for their “value meals,” which offers large portions at a low price. “Supersizing” is a widespread practice at many restaurants, which offers more food, such as a drink and a side dish, for a small additional cost. Recent studies have shown that greater portion size leads to greater intake and extra calories. When watching television or driving down the road, it is quite common to see some sort of advertisement or reference for a popular fast food chain. The fast food industry markets to children in hopes of fostering a fast food habit that will continue into adulthood. Therefore, it is important to realize the impact that fast food has on the daily diet of youth and its involvement in the obesity epidemic. However, does this mean that we should give up on eating at fast food joints entirely? Absolutely not. While hamburgers and chicken nuggets are tempting, some fast food restaurants do offer health conscious items such as the fruit and yogurt parfait or apple dippers. It is critical to keep in mind that moderation and variety are key for a balanced diet. According to the late Dr. Paul Saltman, “What makes food good or bad for you is volume, balance, and interaction. What you eat matters less than how much you eat, when you eat it, and what other foods you’re also eating.”

WRITTEN BY ILIANA NGUYEN. Iliana Nguyen is a Biochemistry and Cell Biology major from John Muir College. She will graduate in 2013.


  1. Boutelle, K., Email Correspondence, 1, Nov. 2011
  2. Boutelle, PhD, Kerri N., Hanaah Fannin, BS, Ron S. New eld, MD, and Lisa Harnack PhD. “Nutritional Quality of Lunch Meal Purchased for Children at a Fast-Food Restaurant.” Childhood Obesity 7.4 (2011): 316-21. Print. Bowman, PhD, Shanthy A., Steven L. Gortmaker, PhD, Cara B. Ebbeling, PhD, Mark A. Pereira, PhD, and David S. Ludwig, MD, PhD. “Effects of Fast-Food Consumption on Energy Intake and Diet Quality Among Children in a National Household Survey.” Pediatrics 113.1 (2044): 112-18. Print.
  3. Gifford Sawyer, Michael, Taylor Harchak, Melissa Wake, and John Lynch. “Four Year Prospective Study of BMI and Mental Health Problems in Young Children.” Pediatrics 128.4 (2011): 677-84. Print.
  4. Rolls, PhD, Barbara J. “ The Supersizing of America Portion Size and the Obesity Epidemic.” Nutrition Today 38.2 (2003): 42-53. Print.
  5. Saltman, Paul, Joel Gurin, and Ira Mothner.  The University of California San Diego Nutrition Book. Boston: Little, Brown, 1993. Print.
  6. Schlosser, Eric. Fast Food Nation: the Dark Side of the All-American Meal. Boston: Houghton Mi in, 2001. Print.
  7. Silverthorn, Ph.D, Dee Unglaub. Human Physiology. 4th ed. San Francisco: Pearon Benjamin Cummings, 2009. Print.
  8. Web. 20 Nov. 2011. <>.