Finding the Optimal Meal Plan

lesson plan adam smith for high school adam smith high school middle school home schooling economic concepts

This lesson helps students to understand the importance of trade-offs and constraints in the context of planning what to eat for the week. A paired reading from Wealth of Nations helps learners practice reading complex texts and extension exercises apply the concept learned. This lesson is appropriate for at-home learning.
Middle-school to high-school students
Three to four class periods, plus extension exercises.


  • Help your learner understand imperfect solutions, trade-offs, and constraints
  • Learn about “optimal” thinking, or the best available option when perfect solutions aren’t available
  • Learn to plan meals and grocery store trips
  • Build confidence in reading complex texts

This lesson has two complementary objectives. The first is to develop an understanding of the economic concept of “optimal” thinking, or thinking about the best option available given the constraints in the real world. This short video may be helpful for teachers who want to understand the difference between the economic and common use of this term. (Teachers may choose to watch with their learners, but it contains consumption and discussion of alcohol.)
The second objective is building competence and independence in grocery and meal planning. Between the ages of six and 11 years old, most children possess the executive functioning capacity to begin helping with meal planning and grocery lists. This chapter excerpt from Jessica Lahey makes the case for teaching children to help with these tasks around the house. (In case the prospect of unloading some chores isn’t tempting enough! If possible, parents should be committed to letting your learner make these decisions.) If you have more restrictions about what meals they can plan, introduce them as an additional step in the plan. Ideally, the meal plan should be put into practice.
This lesson encourages learners to think about the best-case scenario once trade-offs and realistic restrictions on their actions are taken into account. It also asks them to consider who is best positioned to make the necessary trade-offs. 

Optional extension exercise: 

  • Identify economic concepts in grocery shopping and meal planning

This lesson can be taught using the included slide deck and/or the handout paired with this lesson plan. 




Step 1: The perfect plan

Either at the beginning of your class or before the learner arrives, ask them to prepare a plan for five PERFECT meals during the week (they can choose if they will be breakfast, lunch, or supper). It’s up to them to choose what’s perfect. Your learner may choose to cook at home or to get takeaway. 
For meals cooked at home, ask your learner to find recipes online or in cookbooks and come up with a list of ingredients they will need to make their meals. Have your learner check your fridge, freezer, and pantry to see what you already have and what they would need to buy to prepare their meals. Ask them to split the list of ingredients into two lists: one list of ingredients that are already on-hand in their home, and a second list of ingredients they would need to purchase: their “Perfect Grocery List”. 
If your learner has chosen all takeaway meals, don’t worry--this lesson will still work. Have them record the takeout meals they plan to order in place of their grocery items.
If your learner chooses very labour intensive meals prepared at home, you may want to add a step to this lesson plan with a rule about the length of time required to prepare a meal. This information is included in most recipes.

Step 2: Avoiding malnutrition

Unfortunately, we can't always eat what we want. 
Ask your learner to research what a healthy meal looks like. Some potential resources include:
But you (or the learner’s parents) may choose to share the resource used in the learner's home instead. Work with your learners to determine what would make a meal healthy “enough” in your home.

Ask your learner to:
  • Find out how their family normally plans for healthy meals. (Is every meal balanced, or is it balanced through the day?)
  • Identify the food groups that make up a healthy meal. How much of each is appropriate for a healthy meal? What are some examples of each food group? 
  • Prepare a set of rules for a healthy meal.

How many of the “perfect” meals are healthy? Tell your learner how many meals have to be healthy (maybe you have a “treat” meal during the week, and you’re willing to let your learner plan that one). Based on this, ask them to update their plan so that the meals are healthy enough.
Try to be tolerant of their interpretations of the rules. Some meals will be closer than others. For example: Candy and chips won’t fill anyone’s requirements for healthy meals. But what about a sandwich, chips, and carrot sticks? What do you have to add to macaroni and cheese to make it an acceptable meal in your home? 
Whatever you do, don’t just tell your learners what their meals should look like. Let them come up with their own solutions in response to specific feedback, such as “We can use chips as potatoes as a treat, but you still need to choose another vegetable” or “Carrots and corn are both great, but what would you like to include for protein?” If they bring you something that doesn’t meet the criteria, explain why it doesn’t qualify and ask them to update it again. Once they have five acceptable meals planned, ask them to update their grocery list. 

Step 3: Can you afford it?

Unfortunately for our perfect meal plans, we have a budget. (A budget for food helps us make sure we have enough money to spend on other things!)
Give your learner a grocery budget for the week, or ask them to find out what the budget is in their home. Ask them to research online to see if their grocery list will fit in the budget. If it doesn’t, ask them to update their meal plans and grocery lists to stay in the budget. Again, don’t try to direct their choices. 
Some children will have created a meal plan and grocery list that already falls within the budget you give them. In this case, ask them what they would have changed if they did not have enough money. Alternatively, you could ask them if they wanted to get something special for one meal, or if they would rather save the money to use for another purpose. (Only offer this choice if you mean it!) 
If your learner has found that they cannot afford their second-best meal plan, ask them what parts are most expensive and what they are most willing to change. It is important that you let them make decisions about how to make their meal plan work! Offer guidance when asked, but let them make the trade-offs themselves.
Once these changes are complete, ask them to update their ingredient and grocery lists.

Finally: The third-best plan! Is it optimal?

Ask your learner what they think of when they think of the word “optimal”. 

A common answer is that “optimal” means “perfect” or “best”. If your learner says “best”, press them to be more specific: the best of all things? The best in a given situation? 

When economists say something is “optimal”, they don’t mean that it’s the perfect option. They mean that given the trade-offs and constraints that we face, it’s the best option available. It’s possible that it could also be perfect! But often it won’t be. 
So your perfect grocery list was NOT optimal. The grocery list that meets your family’s requirements for healthy meals and fits within their budget is. 


  1. If you can’t have your “perfect” meals, does that mean it doesn’t matter what decisions are made instead?
  2. Who decides what’s optimal? 
  3. Do you think it’s always possible to meet all the criteria for a healthy meal? What would make it harder? 
  4. What if your budget was very small, or you had dietary restrictions? How do rules that are harder to follow affect what your meals look like? 
  5. Can you think of other rules that might affect which meals you could choose for your family?
  6. How many ways are there to plan a healthy and affordable meal?
  7. What would have happened to your perfect meals if your parents got to update the meals for you?
  8. What would have happened to your perfect meals if a nutrition expert who has never met your family got to update the meals for you?
  9. When do you think it’s best for an expert to make decisions? When is it better for the people who the decisions affect to choose? 
  10. How would you spend your grocery budget if you knew that you could use the money you didn’t spend on food any way you wanted?
  11. How would you spend your grocery budget if you knew that the money you didn’t spend would go to your whole family? 
  12. Who would you rather update the meals, once you know the rules for choosing them?
  13. Do you think there are good rules for making these decisions as a family?
  14. Do you think there are good rules that would make it ok for someone outside your family to decide? 


What did Adam Smith think about who decides?

Provide your learners with a copy of the handout, Adam Smith’s Liberal Plan. 
In this excerpt from Adam Smith’s An Inquiry into the Nature and Causes of the Wealth of Nations Book IV, Chapter 9, Smith discusses the idea of economies based on agriculture. When Smith was writing, many people thought economies should be based on agriculture. In the excerpt, Smith talks about a great policymaker who wanted to try to bring about an economy based on agriculture in his country. 
First, have your learner work through the paragraph, either with their peers or with you, to understand what it means. Try to let them figure it out, rather than guiding them too much. 

Discussion/homework questions: 

  1. What does it mean for a country’s economy to be based on agriculture:
  • From the perspective of an economist studying the country?
  • From the perspective of the government of the country? 
  • From the perspective of people living in the country?
  1. Do you believe it would be better for a country to be based on agriculture? If not, what should it be based on? (Justify your answer.)
  2. Do you think there is such a thing as a perfect economy? What does it look like? 
  3. In a way, Adam Smith says Mr. Colbert believed that the perfect economy in France would be based on agriculture. Do you think that, even if he’s right, it would be the optimal economy? 
  4. Who do you believe should get to decide what an economy is based on?  
  5. How does this relate to your optimal grocery list? 

Optimal policy?

Ask your learner to find a news story about a public policy problem. 
What would be their perfect solution to the problem, if there were no trade-offs or rules they had to follow? 
What do they think is the optimal policy in the real world? Have them explain why it is optimal. 
This exercise lends it well to either in-class discussion or a written assignment. 


Extension exercise: Economic Concepts in the kitchen and at the grocery store

Define the following concepts
Complementary good - a good or product that is used with another good or product. For example, if you like peanut butter and jelly sandwiches, then peanut butter and jelly are complementary goods. 
Substitute good - a good that can be used for the same purpose as another good. For example, if a recipe calls for cooking in olive oil and you don’t have any, you could use butter or vegetable oil instead. 
Durable good - a good that is useful over time rather than being used up and consumed. For example, if you purchase a whisk, you can use it over and over in many recipes. 
Consumable good - a good that will be consumed when it’s used. All food items are consumable. Once they are used, you don’t have them any more. Other examples include plastic wrap or tin foil. 
Shelf life - the length of time that a good is useable, consumable, or fit for sale. For example, carrots might keep in the fridge for one month, but bean sprouts will only keep for a few days. Best before dates indicate the shelf life of a product.
How does a change in the price of the ingredient on your list affect your demand for the complementary good?
If an ingredient on your list becomes more expensive, your demand for the complementary good will fall, since you will buy less of the the item on your list. If the ingredients on your list become cheaper, your demand for the complementary good will go up, since you will have more of the item that it goes with. 
How does a change in the price of the ingredients from your list affect your demand for the substitute good? 
If an ingredient on your list becomes more expensive, your demand for the substitutes will go up, since the substitute becomes relatively cheaper. If an ingredient on your list becomes cheaper, the demand for the substitute will go down, since your first choice becomes relatively cheaper. 
Even if a substitute good becomes relatively cheaper, it may not be enough to change your purchasing decision. If your first choice is within your budget you may choose to stick with it.
Are any of the things you need to buy durable goods? Identify them if so.
If your learner needed to buy a piece of kitchen equipment, this would qualify. 
How might a new durable good affect your meal plans in future weeks? 
Once you have a new durable good, it may mean that you can make food you couldn’t make before you purchased it. For instance, if you bought an ice cream machine you could start making ice cream. If you bought a blender you could start making smoothies.
How does the shelf life affect the way you plan your meals for the week?
Meals that use very perishable ingredients may have to be made earlier in the week.
How might shelf life of your ingredients affect your meal plans in future weeks? 
An ingredient with a long shelf life, like rice or beans, can be used in future weeks if the amount purchased is more than what’s needed for the week’s meals. This means more room in the budget for new ingredients.