Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

"A calorie is a calorie" violates the second law of thermodynamics

ncbi.nlm.nih.gov

Post reply on HN
Print view View original

11–20 of 67 posts

Re: "A calorie is a calorie" violates the second law of thermodynamics

#11

Post by kenjackson »

apinstein wrote: post #4

tl;dr version: Calories derived from fat vs protein vs carbohydrates have different inefficiencies in converting them from their theoretical caloric value to their useful work in the body. Fat is the most efficient with a loss of just @ 2-3%, carbs are at 6-8%, protein 25-30%. [edit Most of] this loss is in the form of heat. It was not mentioned why this excess heat would not simply be offset by the body avoiding the…

Funny, I learned this in nutrition class about 20 years ago. It's something that clearly has been known for a long time, yet its never been popuar in the common discourse.

Re: "A calorie is a calorie" violates the second law of thermodynamics

#12

Post by run4yourlives »

"A calorie is a calorie" is good enough, however.

People aren't fat because they are consuming 2500 calories from a Big Mac and Fries rather than 2500 calories from carrots. People are fat because they are consuming 6000 calories and burning off 1300.

The message is simplistic, sure. For a large majority of overweight people though that's all that is required. Somewhere between reducing caloric intake and becoming fit, the message that not all calories are created equal sinks in, if for no other reason that it quickly becomes apparent that you'll starve only eating one meal of McDonald's a day.

Re: "A calorie is a calorie" violates the second law of thermodynamics

#13

Post by cjp »

run4yourlives wrote: post #12

"A calorie is a calorie" is good enough, however. People aren't fat because they are consuming 2500 calories from a Big Mac and Fries rather than 2500 calories from carrots. People are fat because they are consuming 6000 calories and burning off 1300. The message is simplistic, sure. For a large majority of overweight people though that's all that is required. Somewhere between reducing caloric intake and becoming fi…

Negative. You miss the entire point of the article.

Why are people consuming 6000 calories? They are always hungry and eat too much food.

Why are they always hungry? They eat and drink too many carbohydrates. Too many carbohydrates leads to high blood sugar which leads to too much insulin. After the insulin does its job, the blood sugar crashes causing hunger. The cycle repeats, causing problems including insulin resistance, excess fat storage and type 2 diabetes.

What is the solution? Don't consume carbohydrates and avoid the hunger/sugar/insulin cycle.

Re: "A calorie is a calorie" violates the second law of thermodynamics

#14

Post by cschneid »

The other big thing that people end up missing is that most of your weight isn't from the food you eat. That's just where the energy came from. Your weight is oxygen / carbon / water / etc.

Also note: a giant tree doesn't dig out a giant hole where it grows in the ground. The dirt isn't the bulk of the tree's wood.

Re: "A calorie is a calorie" violates the second law of thermodynamics

#15

Post by bruce511 »

cschneid wrote: post #14

The other big thing that people end up missing is that most of your weight isn't from the food you eat. That's just where the energy came from. Your weight is oxygen / carbon / water / etc. Also note: a giant tree doesn't dig out a giant hole where it grows in the ground. The dirt isn't the bulk of the tree's wood.

I'm not sure I follow you here. Aside from a medical condition you're not gonna accumulate water. And I'm not sure " breath less" would be a popular or effective diet technique. Yes, your body needs water and oxygen as part of using food, and turning into muscle or fat, but it's the food that does all the damage. A very brief evidence of this fact are those that exercise all the time (hence have both elevated breathing and water intake, and yet don't gain weight.)

Regarding the tree, you're absolutely right. If only you were a tree that would be a useful comment. Unfortunatly the metabolic process of a tree (all plants) is different to that of an animal. A plant requires water, carbon dioxide and sunlight. Throght the process of photo-synthesis (which only plants can do) carbon is removed from the atmosphere using sunlight as the primary fuel. So, if you like a plant "breaths" sunlight, "eats" air and defecates oxygen.

Re: "A calorie is a calorie" violates the second law of thermodynamics

#16

Post by acon »

cschneid wrote: post #14

The other big thing that people end up missing is that most of your weight isn't from the food you eat. That's just where the energy came from. Your weight is oxygen / carbon / water / etc. Also note: a giant tree doesn't dig out a giant hole where it grows in the ground. The dirt isn't the bulk of the tree's wood.

The fact that a tree builds itself out of thin air is one of my favorite tidbits of knowledge. However, this kind of metabolism is only used by plants. Humans, as all animals, gets their building blocks from what they eat and drink. All the oxygen we use from the air we breathe is exhaled as carbon dioxide.

Re: "A calorie is a calorie" violates the second law of thermodynamics

#17

Post by noarchy »

run4yourlives wrote: post #12

"A calorie is a calorie" is good enough, however. People aren't fat because they are consuming 2500 calories from a Big Mac and Fries rather than 2500 calories from carrots. People are fat because they are consuming 6000 calories and burning off 1300. The message is simplistic, sure. For a large majority of overweight people though that's all that is required. Somewhere between reducing caloric intake and becoming fi…

I expect that you'll end up getting downvoted by the "carbs are evil" crowd, but I think you're largely correct. Too many people are looking for the magic bullet that will let them remain sedentary, overeat, and yet still lose weight.

Re: "A calorie is a calorie" violates the second law of thermodynamics

#18

Post by Groxx »

cjp wrote: post #13
run4yourlives wrote: post #12

"A calorie is a calorie" is good enough, however. People aren't fat because they are consuming 2500 calories from a Big Mac and Fries rather than 2500 calories from carrots. People are fat because they are consuming 6000 calories and burning off 1300. The message is simplistic, sure. For a large majority of overweight people though that's all that is required. Somewhere between reducing caloric intake and becoming fi…

Negative. You miss the entire point of the article. Why are people consuming 6000 calories? They are always hungry and eat too much food. Why are they always hungry? They eat and drink too many carbohydrates. Too many carbohydrates leads to high blood sugar which leads to too much insulin. After the insulin does its job, the blood sugar crashes causing hunger. The cycle repeats, causing problems including insulin res…

Erm... did you read the article?

The only mention of carbohydrate's effect is because it's chosen as a large, easy number to reduce in favor of raising the protein amount, raising the overall inefficiency of the system. They listed, in Atkins-like diets, that shifting from 55% carbs to 8% carbs (with the change going to increased protein intake) results in about 140kcals less useful energy.

That's it. From where in the article are you drawing insulin/diabetes/hunger connections?

Re: "A calorie is a calorie" violates the second law of thermodynamics

#20

Post by ak4life »

cjp wrote: post #13
run4yourlives wrote: post #12

"A calorie is a calorie" is good enough, however. People aren't fat because they are consuming 2500 calories from a Big Mac and Fries rather than 2500 calories from carrots. People are fat because they are consuming 6000 calories and burning off 1300. The message is simplistic, sure. For a large majority of overweight people though that's all that is required. Somewhere between reducing caloric intake and becoming fi…

Negative. You miss the entire point of the article. Why are people consuming 6000 calories? They are always hungry and eat too much food. Why are they always hungry? They eat and drink too many carbohydrates. Too many carbohydrates leads to high blood sugar which leads to too much insulin. After the insulin does its job, the blood sugar crashes causing hunger. The cycle repeats, causing problems including insulin res…

Don't consume carbs? This sounds insane. What about a balanced diet of caloric value inline with one's caloric output?
Post reply on HN