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4.8: Case Study Fast Food Conclusion and Chapter Summary

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    Figure 1


    Case Study Conclusion: What’s Wrong with Fast Food?

    What is wrong with fast food? That is the question that Carlos, who you read about in the beginning of the chapter, asked himself after learning that his friend Kevin eats it five or six times a week, and thinks that this diet is not necessarily that bad for him. In order to find some answers, Carlos went to the website of Kevin’s favorite fast food restaurant and found nutritional information for his typical meal of a cheeseburger, large fries, and a large soda. Some of the information he found is shown in the tables below. Knowing what you now know about nutrition, what aspects of this meal could potentially be harmful to Kevin’s health if he eats like this frequently?

    Nutritional Information for a Typical Fast Food Meal

    Food Calories Total Fat (%DV) Saturated Fat (%DV) Trans Fat Carbohydrates (%DV)
    Burger 540 43% 49% 1 g 15%
    Fries 510 37% 17% 0 g 22%
    Soda 300 0% 0% 0 g 27%
    Total 1,350 80% 66% 1 g 64%
    Food Sodium (%DV) Iron (%DV) Vitamin A (%DV) Vitamin C (%DV) Calcium (%DV)
    Burger  40% 25% 10% 2% 15%
    Fries 15% 6% 0% 30% 2%
    Soda 1% 0% 0% 0% 0%
    Total 56% 31% 10% 32% 17%

    % DV = percentage of adult recommended daily value (DV) for each nutrient, based on a 2,000 Calorie a day diet.

    As Carlos already said to Kevin, fast food meals are often very high in calories. This meal has 1,350 Calories. A typical adult should consume around 2,000 Calories a day, so this single meal has more than half the calories typically needed by a person in one day. Some fast food meals have even more calories. The cheeseburger in this meal has 540 Calories, which is typical for a moderately-sized fast food cheeseburger. But some larger fast food burgers, or burgers with more toppings, can have over 1,000 Calories! As you can see, it can be quite easy to exceed your calorie recommendation for the day if you eat a typical fast food meal, considering that you will probably eat two other meals that day as well.

    What is the problem with consuming excess calories? As you have learned, it is important to maintain energy homeostasis — that is, a balance between the energy you consume and what your body uses. If you eat more calories than your body needs, you will store that extra food energy as fat, which can cause you to become obese. Obesity raises the risk of many diseases and health problems, including cardiovascular disease, type 2 diabetes, stroke, liver disease, cancer, pancreatitis, osteoarthritis, sleep apnea, and asthma. Many of these medical conditions can be deadly, which is why obesity can shorten a person’s lifespan. Although Kevin is only slightly overweight at this point, if he regularly consumes more calories than he uses (which is likely with a diet high in fast food) he will gain excess body fat, raising his risk of obesity and its associated diseases.

    Why do typical fast food meals have so many calories even if they don’t appear to be particularly large? For one, these foods are typically high in fat. Notice that this meal contains 80% of the recommended daily value (DV) of total fat — close to the limit for the entire day! As you have learned, fat is energy dense. One gram of fat has nine Calories, while one gram of protein or carbohydrate has only four Calories. This means that meals high in fat, like this one, will generally have more calories than a lower fat meal of equivalent size. The large amount of fat in the burger and fries contributes to the high energy density of this meal.

    But fat isn’t the only reason this meal is so high in calories. The soda contains 300 Calories — about the same number of calories as three apples! For most people, three apples would be more satiating than a soda. This is in part because apples have fiber, which is filling. As you have learned, sodas and other sugary beverages generally have no other nutrients besides carbohydrates. You can see from the tables that the soda is the largest contributor of carbohydrates to this meal, with very few other nutrients. If Kevin is frequently drinking large sodas, he is getting a significant percentage of his calories from a substance that is not giving him a feeling of fullness, which may cause him to consume more calories overall. In fact, many scientists think that the increase in consumption of sugary beverages has been a major contributor to the obesity epidemic.

    Besides excess calories, what nutrients in this meal could cause health problems? This meal has both a high percentage of saturated fat (66% DV) as well as some trans fat. The American Heart Association recommends that people limit their consumption of saturated fat, since it has been shown to raise the risk of heart disease. Trans fats are particularly dangerous, and can increase the risk of heart disease, stroke, and type 2 diabetes. In fact, in 2015 the U.S. Food and Drug Administration (FDA) ruled that trans fats have not been shown to be safe for human consumption, and ordered food producers to remove them from the food supply by 2018. While some fast food restaurants voluntarily removed trans fats from their food prior to this time, as of early 2017 some restaurants still had items containing trans fats on their menus —like the burger from Kevin’s favorite restaurant.

    Another nutrient that fast food meals tend to have too much of is sodium. This meal has over half the sodium you should eat in a day, mostly from the burger. And this burger isn’t the worst one around — some fast food burgers have double the recommended DV for sodium! Burgers with bacon are particularly high in sodium. Consumption of excess sodium can lead to high blood pressure, cardiovascular disease, and stroke. 

    Consumption of excess nutrients is not the only concern when a person frequently eats fast food. As you can see from the tables, this meal is relatively low in some vitamins and minerals such as vitamin A (10% DV) and calcium (17% DV). As you have learned, vitamin A is important for maintaining normal vision and, in young children, the development of the immune system, among other functions. Calcium is a macromineral needed for bone strength, neutralizing acidity in the digestive tract, and nerve and cell membrane functions. Eating a diet low in specific nutrients can cause a form of malnutrition called unbalanced nutrition. If Kevin eats meals like this frequently, he would have to make sure to get plenty of essential nutrients from other sources in order to maintain his health, which may be difficult if fast food takes the place of healthier foods in his diet. Carlos was correct to be concerned about the lack of fresh food in most fast food meals. Fresh fruits and vegetables contain fiber, phytochemicals, and many vitamins and minerals that are important for maintaining health.

    But as Kevin brought up, is fast food worse than other types of food? While it tends to be particularly high in calories, fat, and sodium, and is not very nutrient dense, the same is true for many other types of meals eaten outside the home. Many chain restaurants have nutritional information listed on their website — you can look up some of your favorites. You might be surprised to learn that some restaurant entrees contain more than 2,000 Calories for a single meal, combined with an excessive amount of saturated fat and sodium. These items are just as bad or worse for your health than some fast food meals.

    The keys to healthy eating are to know what you are consuming and to make good choices. Preparing fresh food at home is usually healthier than eating out, but most restaurants have some healthier options. After Carlos tells Kevin what he found out about Kevin’s favorite meal, Kevin decides to make some changes. He doesn’t want to face a future of obesity and potentially life-threatening health conditions. He decides to pack a healthy lunch to take with him during the day, and will eat more dinners at home. When he does occasionally eat fast food, he will make better choices. Skipping the soda will easily save him 300 Calories. Kevin loves fries, but he realizes that if he orders small fries instead of large, he can save 280 Calories and 20% DV of total fat. If he orders a smaller cheeseburger, he can save an additional 240 Calories and 25% DV total fat. Then if he is still hungry, he can add a piece of fruit from home for additional nutrients. He will also try other options at fast food restaurants, such as salads or grilled chicken sandwiches, which may be healthier. However, he should check the nutritional information first, since some seemingly healthy options can still be high in calories, fat, and salt due to added dressings, sauces, and cheese. Healthy eating and good nutrition doesn’t have to be difficult if you are armed with information and make good choices with your long-term health in mind. 

    Chapter Summary

    In this chapter, you learned how nutrition relates to the functioning of your body and your health. Specifically, you learned that:

    • Nutrients are substances the body needs for energy, building materials, and control of body processes. There are six major classes of nutrients: carbohydrates, proteins, lipids, water, vitamins, and minerals.
    • Essential nutrients cannot be synthesized by the human body, so they must be consumed in food. Nonessential nutrients can be synthesized by the human body, so they need not be obtained directly from food.
    • Macronutrients are nutrients that are needed in relatively large amounts. They include carbohydrates, proteins, lipids, and water. All macronutrients except water provide energy, which is measured in Calories. Micronutrients are nutrients that are needed in relatively small amounts. They do not provide energy. They include vitamins and minerals.
      • Carbohydrates are organic compounds made of simple sugars. Besides sugars, they include starches, glycogen, and cellulose. Dietary carbohydrates come mainly from grains, fruits, and vegetables. They are used for energy, and one gram of carbohydrates provides 4 Calories of energy. Fiber consists of nondigestible carbohydrates that help control blood glucose and cholesterol (soluble fiber) or that stimulate peristalsis and prevent constipation (insoluble fiber).
      • Proteins are organic compounds made of amino acids. Dietary proteins come from sources such as meat, fish, and legumes. Amino acids from foods that are not needed for synthesizing new proteins by the body may be used for energy. One gram of proteins provides 4 Calories of energy. Of the 20 amino acids the human body needs, 9 amino acids are essential.
      • Lipids are organic compounds made of fatty acids. Fatty acids are needed by the body for energy, cell membranes, and other functions. One gram of lipids provides 9 Calories of energy. Only two fatty acids (omega-3 and omega-6) are essential in the diet. Animal fats are mainly saturated fats, whereas plant fats are mainly unsaturated fats. Artificial trans fats are added to many foods and are known to be harmful to human health.
      • Water is essential to life. It is continuously lost from the body in urine, sweat, and exhaled breath, so it must be replenished often. Too little or too much water consumption can be dangerous to health.
      • Vitamins are organic compounds that generally function as coenzymes. As such, they are needed for a wide range of normal body functions and necessary for good health. Most vitamins are essential. Exceptions include vitamins B7 and K, which are made by intestinal bacteria; and vitamin D, which is made in the skin when it is exposed to UV light.
      • Minerals are inorganic chemical elements that are necessary for many body processes and needed for good health. Minerals are not synthesized biologically, so they are essential nutrients. Macrominerals, which are needed in relatively large quantities, include calcium, magnesium, phosphorus, and sodium. Trace minerals, which are needed in much smaller quantities, include cobalt, iodine, iron, and zinc.
      • Preliminary evidence suggests that naturally occurring plant chemicals called phytochemicals may be needed for normal body functions and good health, although they are not currently classified as nutrients. Colorful fruits and vegetables are good food sources of phytochemicals.
    • Healthy eating is fundamentally important for good health. A healthy diet reduces the risk of obesity, cardiovascular disease, cancer, and many other diseases. It also extends life.
    • Nutrition refers to the process of taking in nutrients in food and using them for growth, metabolism, and repair. Good nutrition depends on meeting nutrient needs while maintaining energy balance, called energy homeostasis.
    • The opposite of good nutrition is malnutrition. Malnutrition includes undernutrition, in which there is inadequate energy intake; overnutrition, in which there is excessive energy intake; and unbalanced nutrition, in which there is too much or not enough of specific nutrients, such as vitamin A or calcium.
    • Good nutrition requires healthy eating. This means eating a wide range of nutritious foods that provide the correct balance of nutrients. It also means taking in the correct amount of food energy to balance energy use.
    • Nutrient density refers to how much of a given nutrient a particular food provides, relative to the mass of the food or the amount of Calories it provides. Foods vary greatly in nutrient density — making informed food choices is important for achieving nutrient balance.
    • Energy homeostasis is regulated by the hypothalamus, which controls appetite and satiation, but it also depends on dietary choices and activity levels. Energy density refers to the amount of energy a food provides per unit of mass or volume. Choosing foods with lower or higher energy density as needed to balance energy expenditure can help maintain energy homeostasis.
    • Recommended daily values of nutrients can be used as a general guide to nutrient needs. At the level of individuals, requirements for many nutrients may vary based on age, gender, health status, activity level, and other factors.
    • Tools such as MyPlate and nutrition facts labels are invaluable for healthy eating. MyPlate is a visual guide to the relative proportions of foods in five different food groups (vegetables, fruits, grains, protein, and dairy) that you should eat at each meal. Nutrition facts labels give the nutrient content and ingredients in packaged foods, which can help you choose the most nutritious options.
    • Other tips for healthy eating include making half your grains whole grains and limiting sugar and salt intake.
    • Eating disorders are mental health disorders defined by abnormal eating habits that adversely affect health. They generally begin by young adulthood and are much more common in females than males. Eating disorders are the mental disorders with the highest mortality rate.
      • Anorexia nervosa is an eating disorder in which people consistently eat very little and become extremely thin. They may also develop amenorrhea and other serious health problems. People with anorexia nervosa often fail to appreciate how thin they are and how severe their illness is.
      • Bulimia nervosa is an eating disorder in which people recurrently binge on large amounts of food, followed by purging the food from the body through vomiting, using laxatives, exercising excessively, or other methods. People with bulimia nervosa may have normal weight but often have serious health problems such as electrolyte imbalances and irregular heartbeat.
      • Binge eating disorder is an eating disorder in which people repeatedly binge on large amounts of food, followed by feelings of guilt but not by purging. This generally leads to excessive weight gain, obesity, and other serious disorders.
    • Genes are likely to be involved in the development of eating disorders because eating disorders tend to “run in families.” At a biochemical level, eating disorders may be caused in part by dysregulation of neurotransmitters or the hormones leptin and ghrelin, which normally help maintain the body’s energy homeostasis.
    • Environmental factors that increase the risk of eating disorders include being abused as a child, tight parental control over eating habits, fragile sense of self-identity, and social isolation. Cultural idealization of thinness in females may be a major cause of anorexia nervosa and bulimia nervosa in particular.
    • Treatment of an eating disorder depends on the type and severity of the disorder. Treatment options include mental health counseling, medications, nutritional counseling, and hospitalization. The majority of people with eating disorders recover with treatment.
    • Obesity is a disease in which excess body fat has accumulated to the extent that it is likely to have negative effects on health. Obesity is diagnosed in adults when their body mass index (BMI), which is an estimate of body fatness, is greater than 30 kg/m2. Obesity is diagnosed in children when their BMI is greater than the 95th percentile for children of that age.
      • Obesity may be further categorized by the medical profession as severe obesity, morbid obesity, and super obesity. Obese people who store most of their excess fat in the abdomen have central obesity, putting them at greater risk of adverse health consequences of obesity.
    • A minority of cases of obesity are caused by medications such as antidepressants and steroids or by diseases such as hypothyroidism and binge eating disorder. However, obesity is most commonly caused by a combination of excessive food intake, inadequate physical activity, and genetic susceptibility.
      • Dozens of genes that control appetite and metabolism may predispose people to developing obesity when sufficient food energy is present. While rates of obesity have risen, diets have increased in Calories, mainly from excess carbohydrates (often in the form of sugary drinks), and activity levels have declined due to changes in work and technology.
      • Leptin resistance has been proposed as a physiological mechanism underlying obesity. A decreased sensitivity to leptin results in an inability to detect satiety despite high fat reserves. This causes people to never feel satiated and to overeat and gain weight.
    • Obesity increases the risk of many other health problems and diseases, including cardiovascular disease, type 2 diabetes, certain types of cancer, osteoarthritis, and obstructive sleep apnea. The health consequences of obesity are due to the effects of either increased fat mass or increased numbers of fat cells.
    • Most cases of obesity are treatable or preventable through changes in diet and physical activity that restore energy balance to the body. All types of low-carbohydrate and low-fat diets appear equally beneficial in reducing obesity and its health risks. Other treatments may include medications to control appetite or reduce nutrient absorption and bariatric surgery to modify the digestive tract in ways that limit intake of food and absorption of nutrients from food.
    • Public health approaches to the problem of obesity generally focus on ways to reduce energy consumption or promote physical activity. Specific approaches include limiting access to soft drinks in schools and increasing access to parks.
    • Undernutrition is defined as insufficient intake of nutritious foods. People who are undernourished are usually underweight. Adults are considered underweight if their BMI is less than 18.5 kg/m2. Children are considered underweight if their BMI is less than the 5thpercentile of the reference values for children of the same age.
    • Undernutrition is a more significant problem in children who need nutrients for growth and development. They may become dangerously thin (called wasting) or stop growing so they are too short for their age (stunting). Growth deficits often begin in utero due to maternal undernutrition, resulting in low birthweight and its associated risks.
    • Severe undernutrition may develop into life-threatening syndromes, such as kwashiorkor or marasmus, both of which can be fatal without treatment. Kwashiorkor occurs when the diet is especially deficient in protein, causing edema and other characteristic signs of the syndrome. Marasmus occurs when the diet is especially deficient in food energy, causing extreme emaciation and other abnormalities.
    • Some of the most common micronutrient deficiencies worldwide are iron, vitamin A, and iodine deficiencies. Iron deficiency causes anemia, which in childhood can lead to permanent cognitive and motor deficits. Vitamin A deficiency can weaken the immune system, contribute to anemia, and cause blindness. Iodine deficiency leads to inadequate thyroid hormone, causing goiter and hypothyroidism in adults and intellectual disability in children.
    • The vast majority of undernutrition globally occurs because people do not have enough nutritious food to eat. Although there is enough food to meet the needs of the global human population, the food is unevenly distributed and for many people inaccessible because of poverty. Caused by poverty, undernutrition also contributes to poverty because of its effects on health, growth, development, and ultimately on the ability to work and earn income.
    • Undernutrition is less common in the richer nations than it is elsewhere, but it still occurs because of wealth inequalities and the existence of food deserts, which are areas with limited access to nutritious foods.
    • Treating and preventing undernutrition is a huge and complex problem requiring multifaceted approaches. They include direct nutritional interventions, generally provided through the health-care sector to people who are acutely malnourished, as well as public health interventions that focus on improvements in agriculture, water, sanitation, education, or the like. The most successful interventions have been those that address deficiencies of specific micronutrients such as iodine.
    • Foodborne disease is any disease that is transmitted via food. As many as 76 million Americans a year get a foodborne disease, and thousands of them die from it.
    • Foodborne diseases are caused by microorganisms, toxins, or adulteration of food by foreign bodies. Norovirus and several genera of bacteria cause most foodborne diseases. Toxins that cause foodborne disease may come from the environment or from microorganisms in food. Alternatively, they may be consumed in toxic plants or fungi. Foreign bodies such as cigarette butts and insects can accidentally get into food at any stage.
    • Many foodborne diseases share some of the same symptoms, such as vomiting and diarrhea, but they are quite variable in other ways. The incubation period (time from infection to first symptoms) of a foodborne disease can range from a few hours to many days. The infectious dose (amount that must be consumed to cause disease) can vary greatly depending on the agent of disease.
    • The vast majority of reported cases of foodborne disease occur as sporadic cases in individuals. Only a minority of cases occur as part of a disease outbreak, in which two or more people get the same foodborne disease from a common source, such as the same restaurant.
    • Foodborne disease usually arises from food contamination through improper handling, preparation, or storage of food. The main ways food becomes contaminated are through poor hygiene, cross-contamination, and failure of temperature control.
    • Government agencies such as the Food and Drug Administration are responsible for keeping the food supply safe. Food safety at home depends mainly on following good food safety practices. These range from regular handwashing to maintaining the correct refrigerator temperature.

    This chapter concludes the focus in this FlexBook ® on humans as individuals, but our health and well-being is integrally linked to the world around us. In the next chapter, you will learn about the science of ecology and how we humans interact with the organisms around us and the ecosystems in which we live.

    Chapter Summary Review

    1. Imagine you are a nurse who is assessing the BMI of patients. For each of the patients below, identify whether they are underweight, normal weight, overweight, or obese (and the subcategories of severe obesity, morbid obesity, and super obesity). If you cannot determine BMI category based on the information given, explain why. Then discuss whether each patient may have a health/nutritional concern, or whether this cannot be determined from the information given. Finally, if they do have a health/nutritional concern, list some ways they may be able to improve their health.


    a. An adult with a BMI of 41 kg/m2

    b. An adult with a BMI of 24 kg/m2

    c. An adult with a BMI of 17 kg/m2

    d. A child with a BMI of 27 kg/m2

    2. Which nutrients provide energy for the body?

    A. Vitamins

    B. Minerals

    C. Proteins

    D. All of the above

    E. None of the above

    3. For each of the statements below, choose whether it applies to: soluble fiber, insoluble fiber, both, or neither.

    a. Stimulates movement of food wastes through the large intestine

    b. Slows movement of chyme through the small intestine

    c. Classified as a carbohydrate

    d. Nonessential nutrient

    4. Sometimes one type of nutrient can be converted to another type of nutrient in the body. Give one example of this, and describe when it occurs.

    5. True or False. Trans fat is a type of unsaturated fat.

    6. True or False. Bulimia nervosa always involves vomiting to purge food from the body.

    7. Which is the best definition of essential nutrients?

    A. Nutrients that are needed in large quantities by the body.

    B. Nutrients that must be obtained from food.

    C. Nutrients that provide building blocks for protein synthesis.

    D. Nutrients that provide energy for the body.

    8. Which typically has the highest energy density?

    A. Proteins

    B. Carbohydrates

    C. Sugars

    D. Lipids

    9. If you are reading the nutrition facts label on a food item and see that “partially hydrogenated” oil is one of the ingredients, what type of fat is likely to be present? Is this fat a healthy choice? Why or why not?

    10. Identify two ways in which processed foods are typically less healthy than whole foods.

    11. The table below contains nutritional information listed on a bag of tortilla chips. Read the table and then answer the following questions.

    Serving size 1 oz (28 g) About 8 chips
    Calories per serving 140  
    Total fat per serving 7 g 10% Daily Value (DV)
    Sodium per serving 115 mg 5% DV
    Dietary fiber per serving 1 g  5% DV

    a. If you eat 16 of these tortilla chips, how many Calories have you consumed?

    b. A palm-sized (4 oz) serving of grilled, boneless, skinless chicken breast has about 190 Calories. How does this compare to the Calories in 16 tortilla chips? Which is more energy dense? Explain your answer.

    c. What is the percentage DV of fat, sodium, and dietary fiber in 16 of these chips? If you wanted to maintain a healthy diet, following the DV recommendations, what percentage DV of fat, sodium, and fiber would you have left for the rest of the day after eating a snack of 16 of these chips?

    12. Can you eat too many calories but still be malnourished? Why or why not?

    13. Explain why one person with a BMI of 35 kg/m2 could be considered severely obese, while another person with the same BMI could be considered morbidly obese.

    14. Explain how leptin normally regulates appetite, in the absence of leptin resistance.

    15. Central obesity:

    A. refers to obesity that is due to genetic causes.

    B. refers to obesity that occurs in the middle of the U.S.

    C. refers to a body fat distribution where most of the excess body fat is stored in the abdomen as opposed to the hips.

    D. refers to obesity that has resulted in type 2 diabetes.

    16. Name the demographic group that is more likely to be obese and have eating disorders.

    17. Match each of the statements below with the eating disorder that best matches it. Eating disorder choices are: anorexia nervosa, bulima nervosa, or binge eating disorder. Each disorder is used only once.

    a. People with this disorder often develop an electrolyte imbalance.

    b. People with this disorder typically eat very little.

    c. People with this disorder are at risk of developing type 2 diabetes.

    18. If an undernourished child has a distended abdomen, are they more likely to have kwashiorkor or marasmus? Explain your answer and describe the nutritional deficits that likely caused this undernutrition syndrome.

    19. Do you think foodborne disease can exacerbate or even cause undernutrition? Explain your answer.

    20. True or False. Micronutrient deficiencies in children can cause long-term cognitive deficits.

    21. True or False. The risk of getting a foodborne disease can be eliminated by adopting a vegetarian diet.  

    Image Attributions

    [Figure 1] 
    Credit: Nick Taylor; 
    License: CC BY-NC 3.0