ChemMatters: The Science Behind Calories and Nutrition Facts Labels

ChemMatters: The Science Behind Calories and Nutrition Facts Labels

Our latest ChemMatters episode explains the science behind calories and nutrition facts labels. Find out how scientists first determined the calorie content of food in the 1800s, and how fat, protein and carbohydrate levels on nutrition facts labels are found today.

The video explains that the calorie content of food was determined in the late 1800s by chemist Wilbur O. Atwater. Atwater built a four by eight foot device called a respiration calorimeter, which was big enough to allow a person to step into it! It measured the amount of heat they released, the amount of oxygen they consumed and the carbon dioxide they gave off after eating a variety of foods.

Using this device, Atwater was able to measure the precise amount of energy contained in thousands of food items. He found that carbohydrates and proteins were worth 4 Calories per gram and fats about 9 Calories per gram. This 4-9-4 rule is at the heart of how nutrition facts labels are determined today.

Produced by the American Chemical Society
Animation and motion graphics by Sean Parsons
Directed by Adam Dylewski and Sean Parsons

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  1. Paul Beverage on August 18, 2022 at 5:24 am

    And yet, science continues to prove some of the statements in this video are flat-out wrong, and always were. The details for how things were calculated was informative, but the nutritional assumptions presented are not accurate, and the statements made at the end are ill-informed.

  2. h7opolo on August 18, 2022 at 5:25 am

    i am disgusted that our food nutrition is based on 19th century research. OMG, i hate this world. it’s all lies.

  3. Old Man Silencer on August 18, 2022 at 5:25 am

    You might have had an answer already but weight loss comes from a Calorie deficit. If you do not consume enough Calories to maintain your body it will take the needed energy from fat stores in your body instead. So if you should be eating 2200 Calories a day and only eat 1800 you’re losing weight no matter where those Calories are coming from.

  4. Lexes O'Hara on August 18, 2022 at 5:28 am

    This is a great video for people who don’t understand the basics of nutrition! 🙂

  5. RichhhR on August 18, 2022 at 5:32 am

    Perhaps because they were lacking omega 3 fats, and consuming trans fats and large amounts of sugar.

  6. souped up 240sx on August 18, 2022 at 5:32 am

    PP poopoo my Teacher is making me watch this

  7. un2mensch on August 18, 2022 at 5:37 am

    Fantastic video, thanks!

  8. Mark Smith on August 18, 2022 at 5:38 am

    Heat given off- not actual energy absorbed so nutritional contents are total BS. Its a chemist’s result not a real biochemical analysis which would be very difficult.

  9. Celina Leroy on August 18, 2022 at 5:41 am

    Great video! Thank-you!

  10. PRIVATE EYE on August 18, 2022 at 5:43 am

    Show me the Science….

  11. Gyabu-san on August 18, 2022 at 5:43 am

    Gr.9 ftw

  12. Bert Haimona on August 18, 2022 at 5:47 am

    Interesting talk , but I think i’ll go with 75% Fat , 15% protein , and 10% carb..How much did you get payed by the CDC to put this up??

  13. Food Physics And Body Dynamics on August 18, 2022 at 5:48 am

    Although this is an older video, it is one of my favorites on food and nutrition. While it over-simplifies the causal nature of obesity to overeating, it still presents the data related to the process of converting food to energy via caloric method and is still the best video I have found. There are some newer facts which also are contributors to the obesity issues and health in general. Those are the introduction of ICE as a food item rather than simply a food preservative source of cooling and reducing molecular activity. Today, we gladly add a ‘handful’ [with all the added bacterial components still active on the hand] ice to a ‘smoothie’ loaded with fruits and/or vegetables and blended until liquid. Between the added cold and fluid to the digestive process, there is also the major data overload of getting all those food items in fluid form, thereby passing through the mouth with little or no chewing; the method which not only breaks the food particles down. This chewing is necessary for better absorption, of the nutrients within that luscious mouthful of smooth, cold, sweet, sour, salty, bitter, spicy flavors. Yet further infractions are bombarding our digestive process. This food is NOT getting the benefit of all the enzymes and digestive fluids in the mouth, excreted by the maxillary glands when chewing would have occurred by squirting into the food while still in the mouth. A first step in fixing this major issue is so simple it is almost criminal to not disclose; give up the use of ICE in your food intake. [period] For more on how to use food and nutrition to support a healthier lifestyle, visit our websites: or May you and yours..Be In Good Health. Laura L. Dawson, MSAOM, Dipl.Ac., L.Ac.

  14. Ysabella Wuthrich on August 18, 2022 at 5:51 am

    Hi gr 9 students

  15. Stefan Spinu on August 18, 2022 at 5:52 am

    Amazing video! Please keep posting this kind of high-quality educational content! Cheers

  16. Thomas Zynda on August 18, 2022 at 5:52 am

    Kim Rogers is a demon from hell trying to trick us into eating the food of the devil.

  17. polly10022 on August 18, 2022 at 5:54 am

    I already knew this, it’s very basic.

    I want to know whether:

    Calories -> Kilojoule -> Newton -> Joule per meter. 


  18. heng gerald on August 18, 2022 at 5:54 am


  19. Don Grant on August 18, 2022 at 5:56 am

    This is so much much fake science and there is no way of knowing what our bodies do with the food and drink by the nutritional facts that are just guess or out and out lies!

  20. Indegruv on August 18, 2022 at 5:56 am

    he figured that in the 1800s? Amazing.

  21. moochi on August 18, 2022 at 5:58 am

    Nice vid bro

  22. Rishad D'Souza on August 18, 2022 at 5:59 am

    5:46 Americans are fat because of a diet high in ‘fats’ and sugar.
    Americans are actually fat because of a diet high in carbs, specifically refined carbs, and sugar.
    The seeds for the current obesity epidemic were planted when the carb-heavy food pyramid was designed and promoted by US Health bodies. Companies started removing fat from foods and replaced it with sugar because food without fats tastes crap.

  23. lastochka100 on August 18, 2022 at 5:59 am

    One kilogram of water? Hmm 🤔
    Water is a liquid substance measured in liters.

  24. friebender on August 18, 2022 at 5:59 am

    Glad i found this channel 0.o
    science channels ftw ^^

  25. Beth Moreland on August 18, 2022 at 6:00 am

    it’d be nice to see our "impulse" items change. I would like to see more fruit and veggies at the check out line than chips, soda, baked goods, energy drinks, candy…… just saying. 

  26. Gracel Joylen Ferrer on August 18, 2022 at 6:01 am

    9B da

  27. John Cole on August 18, 2022 at 6:01 am

    This is the only video I found on all of youtube that specifically addresses how each micronutrient is determined

  28. H S on August 18, 2022 at 6:04 am

    90% OF carbs should come from total carbs

  29. Joe Philipson on August 18, 2022 at 6:05 am

    I’m sorry I had to disklike the video. It was at 68 and it needed to be *Nice*.

  30. Evelin Gsbriela on August 18, 2022 at 6:06 am

    The shkient siensies

  31. Manar Moon on August 18, 2022 at 6:07 am

    How watch this vedio and eat hmprgr

  32. Friistyle Fit on August 18, 2022 at 6:07 am

    Great video!

  33. Roberto on August 18, 2022 at 6:07 am

    Buen video pero muy largo

  34. lastochka100 on August 18, 2022 at 6:10 am

    Standard American diet is loaded with carbs and sugar- main cause of diabetes and obesity. On top of which come all the GMO and artificial/synthetic additives.

    FDA needs to revise its recommendations for carb/protein/fat/sugar daily consumption. But what they did instead is increase the allowable norm for sugar intake to 50 grams a day! It really shows how our food industry (and those behind it) are in control of our health and vitality!

  35. Cassandra Mor on August 18, 2022 at 6:11 am

    Less protein and more fresh chlorophyll means less stench. I believe for an active Person, 75% of calories or more can come from carbohydrates, ad they are Fuel for the brain and every cell in our bodies! A gallon of water+ is also vital, and fats mostly go on the outside of our bodies, as plant-oils like avocado, coconut, raspberry, and carrot-seed are very high SPF and make us supple and less dehydrated aka young. Try making ground-flax soap 😉 it will suds up and not leave chemicals in the liver

  36. Tschoo on August 18, 2022 at 6:14 am

    "30 % of food intake should be fat"
    "One third of americans are obese"
    Heck i wonder if there’s an correlation…

  37. Victor Carmona on August 18, 2022 at 6:15 am

    I’m sorry but im not doing a math test every time i get cravings, 

  38. Lerkero on August 18, 2022 at 6:16 am

    A very enjoyable explanation for what calories on nutrition labels mean. I would love to see a follow up about vitamins and minerals if possible. A lot of food is artificially enhanced with vitamins and minerals, but what about the food that naturally has those things?

  39. Mr Hemi on August 18, 2022 at 6:18 am

    Great video

  40. Ata Çalışkan on August 18, 2022 at 6:20 am

    i was curious about how they determine the nutrition facts practically, thanks for th enlighenment

  41. Rachelle Berven on August 18, 2022 at 6:23 am

    Thank you

  42. Tony Brown on August 18, 2022 at 6:24 am

    What truly gets people for weight gain is activity levels and Sugary Carbs smh. Most of those Carbs should come from Nuts, Oats, low intake of grains, and Fruits/veggies