Last night, I took my kids out for an American children’s holiday known as Halloween.
Kids (and some ahem… adults) dress up in costume (I was a penguin this year), go door-to-door, saying “Trick or Treat” and get free candy from the neighbors.
My three kids brought back a record 420 pieces of candy. 
In today’s New York Times, I learned that in the weeks leading up to this holiday, Americans purchased $2.7 BILLION dollars in candy.
So here’s my challenge for you.
Assuming all of that candy is consumed by someone in America, estimate the total number of calories represented by $2.7 billion in candy.
Assuming 3,500 calories consumed results in a person gaining 1 lb (0.45 kg) in weight, estimate how many pounds (or kilograms) of weight the American population will gain. Add a comment below to post your entry.
The winner will receive public acknowledgement of their estimation skills, and I will send them a portion of the candy “tax” I collected from my kids.
Yes, we tax our kids for a portion of their candy collection, as mom and dad provide “infrastructure” and “chaperone” services.
It’s a useful lesson in taxation.
(We tax at a 33% tax rate.)
Mostly it is an excuse to reduce the amount of sugar they will otherwise end up consuming.
For my kids, it’s an excuse to get rid of the candy they don’t like anyways.
Good luck and Happy Halloween!
Entries will be accepted for next 72 hours, and only entries posted as comments below will be considered. A winner will be announced next week.
UPDATE as of Friday, November 4TH AT 12PM ET: New entries are welcome, but not eligible to win, as contest has closed.
329 thoughts on “A Sweet Estimation Question”
Sooo… 2 700 000 000 spent in candies before Halloween.
I’m French, but for what I remember from USA let’s say a 250g bag is worth 3.48$ (that’s a fully random number, but whatever).
It means that ~776 Million candy bags were bought. Which is ~194 000 tons.
Now let’s say 100g of average candy is brings 535 calories to your body (that’s what the candy bag next to me says). It results in more than a thousand billion calories brought to the land of the free and the home of the brave.
So if I keep your assumption of 3500 cal. = 1 lb, MY ANSWER IS 296 490 148 pounds gained by the american population. A little more than 400g/person. Sounds plausible to me 🙂
Happy Halloween from France, Victor !
277 M pounds or 0.87 pounds per person (average)
Facts:
$2.7B spent on candy
Assumptions:
Candy purchased in bags, sizes S, M, L
US Pop 320M
Candy types
– Chocolate: 150 calories / piece –> 60% of total purchases
– Sugar: 100 calories / piece –> 40% of total purchases
Bag Sizes
– Small: 25 pieces/bag, 25% of bags sold, $8/bag, 2500 calories/bag (sugar candy), 3000 calories/bag (chocolate candy)
– Medium: 50 pieces/bag, 50% of bags sold, $12/bag, 5000 calories/bag (sugar candy), 7500 calories/bag (chocolate candy)
– Large: 100 pieces/bag, 25% of bags sold, $20/bag, 10000 calories/bag (sugar candy), 15000 calories/bag (chocolate candy)
Caloric Impact
– 25% of candy calories consumed cannibalize other calories consumed
– 10% of candy calories consumed are burned off through increased activity
CALCULATION
1. # of bags sold:
(25% of bags)*$8/bag*X(bags) (50% of bags)*$12/bag*X(bags) (25% of bags)*$20/bag*X(bags) = $2.7B –> 2X 6X 5X = $2.7B –> 13X = 2.7B –> X=~207M bags sold
2. Segmentation of bags and calories
– Small: 25% of bags –> ~52M bags = ~31M chocolate (93B Calories), ~21M sugar (52.5B Calories)
– Medium: 50% of bags –> ~104M bags = ~62M chocolate (465B Calories), ~42M sugar (~210B Calories)
– Large: 25% of bags –> ~52M bags = ~31M chocolate (465B Calories), ~21M sugar (~210B Calories)
Total Calories = 1495.5B Calories
3. Weight gain impact
1495.5 B Calories / 3500 Calories/pound = 427M pounds
25% offset (cannibalization) = 107M pounds
10% offset (exercise) = 43M pounds
Total weight gain = 427 – (107 43) = 277M pounds = (277/320) pounds per person = ~0.87 pounds per person (average)
Assuming that people buy treats in packs and not individually, a large surface store sells a box of 50 Hershey treats for about $10
If 2,7 x 10^9 dollars are spent on treats, it represents 1,35 x 10^10 treats sold.
If average ‘fun size’ or ‘snack size’ treat calorie amount is 75 cal (from Twizzlers to Peanuts M&M)
This will represent approximately 1 x 10^12 calories consumed.
If 3500 calories result in gaining 1 lb, then 1 x 10^12 calories consumed will represent approximately 2,89 x 10^8 lbs
The total American population will gain approximately 289 000 000 lbs.
154M lbs weight gained by US population.
270 million calories
250,000 lbs
~120 million lbs
Assumption: Candy (chocolate or otherwise) that costs $1.5 would have ~250 calories.
Assume:
US Population 319,000,000
All candy purchased is consumed
Also assume Halloween participants do not buy a candy bar one at a time but take advantage of buying variety packs for a bulk discount. Assume further that a variety pack is $15 and consists of:
3 packs of M&M’s
2 packs of Peanut Butter chocolate
2 packs of snickers
2 milky way bars
3 pieces of twix
Estimate calorie content in variety pack as (using above pack distribution): 220 180 160 160 150 = 870 calories per variety pack.
Given data:
Dollars spent $2,700,000,000
3,500 calories consumed (not counting any net effects) is equivalent to a 1 lb weight gain
Calculations based on given data and initial estimations:
Calories per dollar = 870 / 15 = 58 calories for every dollar spent
Total calories represented by purchases = $2.7 billion x 58 = 156.6 billion calories (answer to first question posed)
Total weight gain by American population = 156.6 billion / 3,500 = 44,742,857 lbs collectively (answer to second question posed)
Weight gain per person = 44,742,857 / 319,000,000 = 0.14 lbs
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I can actually estimate just by glancing at the total calories purchased that there are close to 500 calories per person available and since 500 is one-seventh of 3,500 then the weight gain would be one-seventh of a pound per person. Matching this up with my instincts I feel it passes the “sniff test”.
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Caveats: The variety pack might even be cheaper (maybe a Costco variety pack might be 20% cheaper than my estimate which would result in a weight gain per person of 0.17 lbs). I’m pretty confident on my estimation of the population but I can construct a data table and do sensitivity analysis on my final estimation based on varying 1) the price of the variety pack 2) total calories represented in the variety pack. This will give me a range with lower and upper confidence bounds. That is for a more rigorous approach to the problem and I would use that method only if I had 5 minutes to spare on a spreadsheet. Otherwise, the estimation itself can be done mentally or quickly on the back of an envelope.
20,571,428.57 pounds
Approximately 140 million lbs.
Total cost = $2.7b
Average cost per candy = 50 cents
Total candies = 5.4b
Calories per candy = 150
Total calories = 810b
Weight gained per 3500 calories = 1lb
Weight gained by 810b calories = 0.2b lbs