3.2 – When Enough is Enough

Learning Objective

  • Judge food portion sizes compared to serving sizes and analyze the role portion distortion has played in the current food environment.


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 2020-2025 Dietary Guidelines for Americans a challenge. In many restaurants and eating establishments, portion sizes have increased, use of saturated fats and added sugars 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.

As we continue this discussion, we need to understand a couple of terms. A portion of food is the amount you choose to take and consume.  A serving is the standard measured size of the food as listed on the food label or determined by expert consensus.

Table 3.2.1 Comparison of Portions and Calories twenty years ago and today.
Infographic on Portion distortionA table comparing portion size and calorie count of five food items.

An image of a table comparing portions and calories of the same foods. First comparison is a bagel, portion size 20 years ago was 3 Inches in diameter and had 140 calories, today the portion is 6 inches and 350 calories. The second item is a cheeseburger, portion size 20 years ago was 1, and the calories 333. Today the portion size is 1, with calorie count of 590. The Third Item is spaghetti with meatballs. Portion size 20 years ago was 1 cup of sauce and three small meatballs. The calorie count was 500. Portion size today is 2 cups of sauce and three large meatballs, with a calorie count of 1,020. The Fourth item is soda, portion size 20 years ago was 6.5 ounces, and 82 calories. Today the portion size is 20 ounces, with 250 calories. The last item is a blueberry muffin. portion size 20 years ago was 1.5 ounces, with 210 calories. Portion size today is 5 ounces, with 500 calories.


Dietitians have come up with some good hints to help people judge the size of their portion of food. Some suggest using common items such as a deck of cards while others advocate using your hand as a measuring rule. See Table 3.2.2 for some examples.


Table 3.2.2: Determining Food Portions; American Cancer Society. “Controlling Portion Sizes.” Last revised January 2019

A table comparing a food product’s portion to objects and hand sizes
Food Product Amount Object Comparison Hand Comparison
Pasta, Rice ½ c. A Tennis Ball Cupped hand
Fresh vegetables, cereal, soup, fruit, casserole 1 c. A Baseball N/A
Cooked vegetables, chips, crackers, pretzels ½ c. or 1 ounce Cupped Hand N/A
Meat, poultry, fish 3 oz. Playing Cards The palm of your hand
Milk or other beverages 1 c. Fist N/A
Salad dressing, peanut butter, cream cheese 1 Tbsp. Thumb N/A
Oil 1 tsp. Thumb tip N/A


A table showing meal planning guidelines for carbohydrates
Choose three to five servings with each meal.
Examples of one serving:
Bread and Starches

  • 1 slice bread or small roll
  • ⅓ c. rice or pasta
  • ½ c. of cooked cereal or potatoes
  • ¾ c. dry cereal
  • ½ c. corn

  • 1 piece, such as a small pear
  • 1 c. fresh fruit
  • ½ c. canned fruit
  • ½ c. fruit juice

  • 1 c. skim or low fat
  • 1 c. unsweetened low-fat yogurt
A table showing meal planning guidelines for Meats and Proteins
Choose one to three servings with each meal.
Examples of one serving:
  • 1 oz. lean meat, poultry, or fish
  • 1 egg
  • 1 oz. cheese
  • ¾ c. low-fat cottage cheese
A table showing meal planning guidelines for fats
Choose one to three servings with each meal.
Examples of one serving:
  • 1 tsp. margarine, oil, or mayonnaise
  • 1 Tbsp. salad dressing or cream cheese
A table showing meal planning guidelines for free foods
Free Foods
Use as desired
Foods with less than 20 calories per serving.*

  • Most vegetables
  • Sugar-free soda
  • Black coffee or plain tea


Key Takeaway

  • Judging portion sizes can be done using your hand or household objects in comparison. It can also be done using the MyPlate guide to determine how much food is a portion of that meal.


Discussion Starter

  1. Why is it important to judge portion sizes properly? Explain why it can be tricky to read food labels and figure out the caloric content for one serving.


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Nutrition 100 Nutritional Applications for a Healthy Lifestyle Copyright © by Lynn Klees and Alison Borkowska is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License, except where otherwise noted.

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