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19.1: Calories - Quantity and Quality

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    Learning Objective
    • Know the daily recommended guidelines to achieve a healthy diet.
    • Learn how to build a healthy plate.
    • Learn about sports nutrition.

    A History of Food Guidance in the U.S.

    The U.S. Dietary Guidelines for Americans and the DRI are important scientific reports to educate health professionals about nutrition and to guide government and other health-related organizations to develop evidence-based health policies that improve the health of all Americans. The United States government has also been providing food and nutrition guidance directly to the public for more than a century to help individuals make healthier dietary and lifestyle choices . You may have heard about "the Four Food Groups" or "The Food Guide Pyramid" or most recently, "My Plate." The government food guidance system has evolved over the years as our understanding of nutrition science and the impact of diet and lifestyle on health has grown. If you are interested in learning more about the history of food guidance in the U.S. a list and description of former tools can be found at:


    MyPlate is the most up-to-date nutrition teaching tool. MyPlate was developed by the United States Department of Agriculture (U.S.D.A.) Center for Nutrition Policy and Promotion as an easy to use visual guide to help all American develop healthy eating patterns. It replaces the former MyPyramid teaching tool and correlates with the 2015 - 2020 U.S. Dietary Guidelines.

    MyPlate organizes foods with similar nutritional value into specific food groups and provides recommendations about how to build a healthy diet. The website also provides a wide range of support materials including information about each food group, an individualized meal planner, recipes and professional videos and handouts such as the MyPlate, MyWins poster shown below to support learning for people of all ages.

    Figure \(\PageIndex{1}\): Ideal healthy plate.

    MyPlate Key Messages include:

    • Focus on whole fruits
    • Vary your veggies
    • Vary your protein routine
    • Make half your grains whole grains
    • Move to low-fat or fat-free milk or yogurt
    • Drink and eat beverages and food with less sodium saturated fat and added sugars
    • Start with small changes that you can enjoy, like having an extra piece of fruit today

    To learn more about MyPlate visit:

    Building a Healthy Plate: Choose Nutrient-Dense Foods

    Click on the different food groups listed to view their food gallery:

    Planning a healthy diet using the MyPlate approach is not difficult. According to the icon, half of your plate should have fruits and vegetables, one-quarter should have whole grains, and one-quarter should have protein. Dairy products should be low-fat or non-fat. The ideal diet gives you the most nutrients within the fewest calories. This means choosing nutrient-rich foods.

    Fill half of your plate with red, orange, and dark green vegetables and fruits, such as kale, bok choy, kalo (taro), tomatoes, sweet potatoes, broccoli, apples, mango, papaya , guavas, blueberries, and strawberries in main and side dishes. Vary your choices to get the benefit of as many different vegetables and fruits as you can. You may choose to drink fruit juice as a replacement for eating fruit. (As long as the juice is 100 percent fruit juice and only half your fruit intake is replaced with juice, this is an acceptable exchange.) For snacks, eat fruits, vegetables, or unsalted nuts.

    Fill a quarter of your plate with grains such cereals, breads, crackers, rice, and pasta. Half of your daily grain intake should be whole grains. Read the ingredients list on food labels carefully to determine if a food is comprised of whole grains such as 100% whole wheat bread, brown rice and whole grain oats.

    Select a variety of protein foods to improve nutrient intake and promote health benefits. Each week, be sure to include a nice array of protein sources in your diet, such as nuts, seeds, beans, legumes, poultry, soy, and seafood. The recommended consumption amount for seafood for adults is two 4-ounce servings per week. When choosing meat, select lean cuts. Be conscious to prepare meats using little or no added saturated fat, such as butter.

    If you enjoy drinking milk or eating milk products, such as cheese and yogurt, choose low-fat or nonfat products. Low-fat and nonfat products contain the same amount of calcium and other essential nutrients as whole-milk products, but with much less fat and calories. Calcium, an important mineral for your body, is also available in lactose-free and fortified soy beverage and rice beverage products. You can also get calcium in vegetables and other fortified foods and beverages. You can learn more about "dairy free" sources of calcium by clicking the "Dairy" link on the ChooseMyPlate website.

    Fats are essential for your diet as they contain valuable essential fatty acids, but the type you choose and the amount you consume is important. Be sure to choose primarily plant-based liquid oils like olive, soybean and canola oil rather than solid animal fats like butter and lard. You can also get oils from many types of fish, as well as avocados, and unsalted nuts and seeds. Although oils are essential for health they do contain about 120 calories per tablespoon. It is vital to balance oil consumption with total caloric intake. The Nutrition Facts label provides the information to help you make healthful decisions.

    In short, substituting vegetables and fruits in place of foods high in added sugars, solid/saturated fats, and sodium is a good way to make a nutrient-poor diet healthy again. Vegetables are full of nutrients and antioxidants that help promote good health and reduce the risk for developing chronic diseases such as stroke, heart disease, high blood pressure, Type 2 diabetes, and certain types of cancer. Starting with these small shifts in your diet as mentioned above will boost your overall health profile.

    Table \(\PageIndex{1}\): Food Replacements.

    Instead of… Replace with…
    Sweetened fruit yogurt Plain fat-free yogurt with fresh fruit
    Whole milk Low-fat or fat-free milk
    Cheese Low-fat or reduced-fat cheese
    Bacon or sausage Canadian bacon or lean ham
    Sweetened cereals Minimally sweetened cereals with fresh fruit
    Apple or berry pie Fresh apple or berries
    Deep-fried French fries Oven-baked French fries or sweet potato baked fries
    Fried vegetables Steamed or roasted vegetables
    Sugary sweetened soft drinks Seltzer mixed with 100 percent fruit juice
    Recipes that call for sugar Experiment with reducing amount of sugar and adding spices (cinnamon, nutmeg, etc…)

    Source: Food Groups. US Department of Agriculture. Updated April 19, 2017. Accessed November 22, 2017.

    The MyPlate Planner can be used to create an individualized plan with the number of servings and portion sizes from each food group to eat each day to achieve a healthy diet. You can access the MyPlate Planner from the ChooseMyPlate website:

    When Enough Is Enough

    Estimating Portion Size

    Have you ever heard the expression, “Your eyes were bigger than your stomach?” This means that you thought you wanted a lot more food than you could actually eat. Amounts of food can be deceiving to the eye, especially if you have nothing to compare them to. It is very easy to heap a pile of mashed potatoes on your plate, particularly if it is a big plate, and not realize that you have just helped yourself to three portions instead of one.

    The food industry makes following the 2015 Dietary Guidelines a challenge. In many restaurants and eating establishments, portion sizes have increased, use of SoFAS has increased, and consequently the typical meal contains more calories than it used to. In addition, our sedentary lives make it difficult to expend enough calories during normal daily activities. In fact, more than one-third of adults are not physically active at all.

    Figure \(\PageIndex{2}\): A Comparison of Serving Sizes.


    As food sizes and servings increase it is important to limit the portions of food consumed on a regular basis. Dietitians have come up with some good hints to help people tell how large a portion of food they really have. Some suggest using common items such as a deck of cards while others advocate using your hand as a measuring rule.

    See Table below for some examples.

    Source: American Cancer Society. “Controlling Portion Sizes.” Last revised January 12, 2012.

    Table \(\PageIndex{2}\): Determining Food Portions.

    Food Product Amount Object Comparison Hand Comparison
    Pasta, rice ½ c. Tennis ball Cupped hand
    Fresh vegetables 1 c. Baseball  
    Cooked vegetables ½ c.   Cupped hand
    Meat, poultry, fish 3 oz. Deck of cards Palm of your hand
    Milk or other beverages 1 c. Fist  
    Salad dressing 1 Tbsp. Thumb  
    Oil 1 tsp. Thumb tip

    everyday connection

    If you wait many hours between meals, there is a good chance you will overeat. To refrain from overeating try consuming small meals at frequent intervals throughout the day as opposed to two or three large meals. Eat until you are satisfied, not until you feel “stuffed.” Eating slowly and savoring your food allows you to both enjoy what you eat and have time to realize that you are full before you get overfull. Your stomach is about the size of your fist but it expands if you eat excessive amounts of food at one sitting. Eating smaller meals will diminish the size of your appetite over time so you will feel satisfied with smaller amounts of food.

    Discretionary Calories

    When following a balanced, healthful diet with many nutrient-dense foods, you may consume enough of your daily nutrients before you reach your daily calorie limit. The remaining calories are discretionary (to be used according to your best judgment). To find out your discretionary calorie allowance, add up all the calories you consumed to achieve the recommended nutrient intakes and then subtract this number from your recommended daily caloric allowance. For example, someone who has a recommended 2,000-calorie per day diet may eat enough nutrient-dense foods to meet requirements after consuming only 1,814 calories. The remaining 186 calories are discretionary. See Table \(\PageIndex{1}\). These calories may be obtained from eating an additional piece of fruit, adding another teaspoon of olive oil on a salad or butter on a piece of bread, adding sugar or honey to cereal, or consuming an alcoholic beverage[1].

    The amount of discretionary calories increases with physical activity level and decreases with age. For most physically active adults, the discretionary calorie allowance is, at most, 15 percent of the recommended caloric intake. By consuming nutrient-dense foods, you afford yourself a discretionary calorie allowance.

    Table \(\PageIndex{3}\): Sample Menu Plan Containing 2,000 Calories.

    Meal Calories Total Meal/Snack Calories
    1 scrambled egg 92  
    with sliced mushrooms and spinach 7  
    ½ whole-wheat muffin 67  
    1 tsp. margarine-like spread 15  
    1 orange 65  
    8 oz. low-sodium tomato juice 53 299
    6 oz. fat-free flavored yogurt 100  
    with ½ c. raspberries 32 132
    1 sandwich on pumpernickel bread 160  
    with smoked turkey deli meat, 30  
    4 slices tomato 14  
    2 lettuce leaves 3  
    1 tsp. mustard 3  
    1 oz. baked potato chips 110  
    ½ c. blueberries, with 1 tsp. sugar 57  
    8 oz. fat-free milk 90 467
    1 banana 105  
    7 reduced-fat high-fiber crackers 120 225
    1 c. Greek salad (tomatoes, cucumbers, feta) 150  
    with 5 Greek olives, 45  
    with 1.5 tsp. olive oil 60  
    3 oz. grilled chicken breast 150  
    ½ c. steamed asparagus 20  
    with 1 tsp. olive oil, 40  
    with 1 tsp. sesame seeds 18  
    ½ c. cooked wild rice 83  
    with ½ c. chopped kale 18  
    1 whole-wheat dinner roll 4  
    with 1 tsp. almond butter 33 691
    (Total calories from all meals and snacks = 1,814)
    Discretionary calorie allowance: 186

    (Total calories from all meals and snacks = 1,814)
    Discretionary calorie allowance: 186

    Web Links and DRI

    You can access the MyPlate Planner from the ChooseMyPlate website:

    Recommended amounts of food from each food group at different calorie levels can be found on the link:

    Dietary Reference Intakes (DRIs) are more than numbers in the table, even though that is often how many people view them. DRIs and Dietary Guidelines provide different information for different audiences.

    • Dietary Guidelines provide qualitative advice to the public about diet and chronic disease prevention and maintaining health.
    • DRIs provide quantitative advice to professionals about amounts of nutrients or food components to be of benefit.
    • DRIs are a collective term to refer to these components:
      • Estimated Average Requirement (EAR)
      • Recommended Dietary Allowance (RDA)
      • Adequate Intake (AI)
      • Tolerable Upper Intake Level (UL). A number of people refer to the UL as simply the “upper limit”, leaving off “tolerable”.

    The RDA is the measure that professionals use to assess the quality of people's diets. It is the requirement estimated to meet the needs of 97.5% of the population. But the RDA is calculated using the EAR. Therefore, the EAR needs to be set before an RDA can be set. There must be applicable research in order to set an EAR. An EAR is the estimated requirement for 50% of the population (hence the average in its name).

    Nutrition and the Athlete

    Nutrition is essential to your performance during all types of exercise. The foods consumed in your diet are used to provide the body with enough energy to fuel an activity regardless of the intensity of activity. Athletes have different nutritional needs to support the vigorous level they compete and practice at.

    Energy Needs

    To determine an athletes nutritional needs, it is important to revisit the concept of energy metabolism. Energy intake is the foundation of an athlete’s diet because it supports optimal body functions, determines the amount of intake of macronutrients and micronutrients, and assists in the maintaining of body composition. Energy needs for athletes increase depending on their energy expenditure. The energy expended during physical activity are contingent on the intensity, duration, and frequency of the exercise. Competitive athletes may need 3,000 to over 5,000 calories daily compared to a typical inactive individual who needs about 2,000 calories per day. Energy needs are also affected by an individual’s gender, age, and weight. Weight-bearing exercises, such as running, burn more calories per hour than non-weight bearing exercises, such as swimming. Weight-bearing exercises requires your body to move against gravity which requires more energy. Men are also able to burn more calories than women for the same activity because they have more muscle mass which requires more energy to support and move around.[1]

    Body weight and composition can have a tremendous impact on exercise performance. Body weight and composition are considered the focal points of physique for athletes because they are the able to be manipulated the most. Energy intake can play a role in manipulating the physiques for athletes. For individuals competing in sports such as football and weight lifting, having a large amount of muscle mass and increased body weight may be beneficial. This can be obtained through a combination of increased energy intake, and protein. Although certain physiques are more advantageous for specific sports, it is important to remember that a single and rigid “optimal” body composition is not recommended for any group of athletes.[2]

    Macronutrient Needs

    The composition of macronutrients in the diet is a key factor in maximizing performance for athletes. Carbohydrates are an important fuel source for the brain and muscle during exercise. Carbohydrate storage in the liver and muscle cells are relatively limited and therefore it is important for athletes to consume enough carbohydrates from their diet. Carbohydrate needs should increase about 3-10 g/kg/day depending on the type of training or competition.[3] See Table \(\PageIndex{1}\) for carbohydrate needs for athletes depending on the intensity of the exercise.

    Table \(\PageIndex{4}\): Daily Needs for Carbohydrate Fuel.
    Activity Level Example of Exercise Increase of Carbohydrate (g/kg of athlete’s body weight/day)
    Light Low intensity or skill based activities 3-5
    Moderate Moderate exercise program (about 1 hour per day) 5-7
    High Endurance program (about 1-3 hours per day of moderate to high intensity exercise) 6-10
    Very High Extreme commitment (4-5 hours per day of moderate to high intensity exercise) 8-12

    Source: Nutrition and Athletic Performance. American College of Sports Medicine.Medicine & Science in Sports & Exercise. 2016; 48(3), 543- 568. Accessed March 17, 2018.

    Fat is a necessary component of a healthy diet to provide energy, essential fatty acids and to facilitate the absorption of fat-soluble vitamins. Athletes are recommended to consume the same amount of fat in the diet as the general population, 20-35% of their energy intake. Although these recommendations are in accordance with public health guidelines, athletes should individualize their needs based on their training level and body composition goals. Athletes who choose to excessively restrict their fat intake in an effort to lose body weight or improve body composition should ensure they are still getting the minimum recommended amount of fat. Fat intakes below 20% of energy intake will reduce the intake of fat-soluble vitamins and essential fatty acids, especially omega 3’s. [4]

    Although protein accounts for only about 5% of energy expended, dietary protein is necessary to support metabolic reactions (that generate ATP), and to help muscles with maintenance, growth, and repair. During exercise, these metabolic reactions for generating ATP rely heavily on proteins such as enzymes and transport proteins. It is recommended that athletes consume 1.2 to 2.0 g/kg/day of proteins in order to support these functions. Higher intakes may also be needed for short periods of intense training or when reducing energy intake.[5] See Table \(\PageIndex{2}\) below for a better representation of protein needs depending on extent of training and dietary sources.

    Table \(\PageIndex{5}\): The Recommended Protein Intakes for Individuals.
    Group Protein Intake (g/kg body weight)
    Most adults 0.8
    Endurance athletes 1.2 to 1.4
    Vegetarian endurance athletes 1.3 to 1.5
    Strength athletes 1.6 to 1.7
    Vegetarian strength athletes 1.7 to 1.8

    Source: Dietary Reference Intakes, 2002 ACSM/ADA/Dietitians of Canada Position Statement: Nutrition & Athletic Performance, 2001. Accessed March 17, 2018.

    It is important to consume adequate amounts of protein and to understand that the quality of the protein consumed affects the amount needed. High protein foods such as meats, dairy, and eggs contain all of the essential amino acids in relative amounts that most efficiently meet the body’s needs for growth, maintenance and repair of muscles. Vegetarian diets contain protein that has lower digestibility and amino acid patterns that do not match human needs as closely as most animal proteins. To compensate for this as well as the fact that plant food protein sources also contain higher amounts of fiber, higher protein intakes are recommended for vegetarian athletes. (See Table 16.2 “The Recommended Protein Intakes for Individuals” )

    Micronutrient Needs

    Vitamins and minerals are essential for energy metabolism, the delivery of oxygen, protection against oxidative damage, and the repair of body structures. When exercise increases, the amount of many vitamins and minerals needed are also increased due to the excess loss in nutrients. Currently, there is not special micronutrient recommendations made for athletes but most athletes will meet their needs by consuming a balanced diet that meets their energy needs. Because the energy needs of athletes increase, they often consume extra vitamins and minerals. The major micronutrients of concern for athletes include iron, calcium, vitamin D, and some antioxidants. [6]

    Web Links

    Estimated Calorie Needs per Day, by Age, Sex, and Physical Activity:

    Nutrition and a Healthy Diet

    There are five key factors that make up a healthful diet:

    1. A diet must be adequate, by providing sufficient amounts of each essential nutrient, as well as fiber and adequate calories.
    2. A balanced diet results when you do not consume one nutrient at the expense of another, but rather get appropriate amounts of all nutrients.
    3. Calorie control is necessary so that the amount of energy you get from the nutrients you consume equals the amount of energy you expend during your day’s activities.
    4. Moderation means not eating to the extremes, neither too much nor too little.
    5. Variety refers to consuming different foods from within each of the food groups on a regular basis.

    A healthy diet is one that favors whole foods. As an alternative to modern processed foods, a healthy diet focuses on “real” fresh whole foods that have been sustaining people for generations. Whole foods supply the needed vitamins, minerals, protein, carbohydrates, fats, and fiber that are essential to good health. Commercially prepared and fast foods are often lacking nutrients and often contain inordinate amounts of sugar, salt, saturated and trans fats, all of which are associated with the development of diseases such as atherosclerosis, heart disease, stroke, cancer, obesity, diabetes, and other illnesses. A balanced diet is a mix of food from the different food groups (vegetables, legumes, fruits, grains, protein foods, and dairy).


    An adequate diet is one that favors nutrient-dense foods. Nutrient-dense foods are defined as foods that contain many essential nutrients per calorie. Nutrient-dense foods are the opposite of “empty-calorie” foods, such as sugary carbonated beverages, which are also called “nutrient-poor.” Nutrient-dense foods include fruits and vegetables, lean meats, poultry, fish, low-fat dairy products, and whole grains. Choosing more nutrient-dense foods will facilitate weight loss, while simultaneously providing all necessary nutrients.


    Balance the foods in your diet. Achieving balance in your diet entails not consuming one nutrient at the expense of another. For example, calcium is essential for healthy teeth and bones, but too much calcium will interfere with iron absorption. Most foods that are good sources of iron are poor sources of calcium, so in order to get the necessary amounts of calcium and iron from your diet, a proper balance between food choices is critical. Another example is that while sodium is an essential nutrient, excessive intake may contribute to congestive heart failure and chronic kidney disease in some people. Remember, everything must be consumed in the proper amounts.


    Eat in moderation. Moderation is crucial for optimal health and survival. Eating nutrient-poor foods each night for dinner will lead to health complications. But as part of an otherwise healthful diet and consumed only on a weekly basis, this should not significantly impact overall health. It’s important to remember that eating is, in part, about enjoyment and indulging with a spirit of moderation. This fits within a healthy diet.

    Monitor food portions. For optimum weight maintenance, it is important to ensure that energy consumed from foods meets the energy expenditures required for body functions and activity. If not, the excess energy contributes to gradual, steady accumulation of stored body fat and weight gain. In order to lose body fat, you need to ensure that more calories are burned than consumed. Likewise, in order to gain weight, calories must be eaten in excess of what is expended daily.


    Variety involves eating different foods from all the food groups. Eating a varied diet helps to ensure that you consume and absorb adequate amounts of all essential nutrients required for health. One of the major drawbacks of a monotonous diet is the risk of consuming too much of some nutrients and not enough of others. Trying new foods can also be a source of pleasure—you never know what foods you might like until you try them.

    Developing a healthful diet can be rewarding, but be mindful that all of the principles presented must be followed to derive maximal health benefits. For instance, introducing variety in your diet can still result in the consumption of too many high-calorie, nutrient poor foods and inadequate nutrient intake if you do not also employ moderation and calorie control. Using all of these principles together will promote lasting health benefits.


    • MyPlate is the most up-to-date nutrition teaching tool developed by the United States Department of Agriculture (U.S.D.A.) Center for Nutrition Policy and Promotion as an easy to use visual guide to help all American develop healthy eating patterns.
    • Planning a healthy diet using the MyPlate approach is not difficult. According to the icon, half of your plate should have fruits and vegetables, one-quarter should have whole grains, and one-quarter should have protein. Dairy products should be low-fat or non-fat.
    • Energy needs for athletes increase depending on their energy expenditure. The energy expended during physical activity are contingent on the intensity, duration, and frequency of the exercise. Competitive athletes may need 3,000 to over 5,000 calories daily compared to a typical inactive individual who needs about 2,000 calories per day. Energy needs are also affected by an individual’s gender, age, and weight.
    • There are five key factors that make up a healthful diet namely: a. adequacy, b. balance, c. calorie control, d. moderation, and e. variety.
    • The total number of calories a person needs each day varies depending on a number of factors, including the person’s age, sex, height, weight, and level of physical activity.

    Contributors and Attributions

    19.1: Calories - Quantity and Quality is shared under a CC BY-NC-SA 4.0 license and was authored, remixed, and/or curated by LibreTexts.

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