[pashapiro]

One of the things I wonder about is how many calories your body can actually metabolize into fat and glycogen in a given day. For example, if you eat 15,000 calories, how many of those calories will your body just pass right through your digestive tract? I could see liquid calories like pop or juice being metabolized easily, but do all the beans in a Chipotle burrito end up clinging on your thighs and gut also?

[mod]

Here's a reddit thread that poses the same question:

https://www.reddit.com/r/askscience/comments/p1qhc/is_there_...

[buu700]

Similar thread that I thought was pretty interesting:

https://www.reddit.com/r/askscience/comments/4ra09i/joey_che...

[dahart]

> if you eat 15,000 calories, how many of those calories will your body just pass right through your digestive tract?

Depends on how much you're burning, how much you weigh, and how many calories you normally eat. If you're not used to eating that much, you will find it really hard to.

There are loads of videos of average build people trying to eat 8000 or more calories, and at least some end up puking like this guy -- does that count as passing through the digestive tract? ;)

https://youtu.be/jWgsLGJUOc0

> I could see liquid calories like pop or juice being metabolized easily, but do all the beans in a Chipotle burrito end up clinging on your thighs and gut also?

When you eat more than you need in the form of a combination of fats & carbs, since carbs metabolize faster, fats get stored.

A Chipotle burrito is very high on fats, and carbs, and calories. So the answer is that the burrito will hit the thighs or waist almost as easily as juice, but it's not the beans, it's the whole burrito, and specifically the tortilla and cheese, sour cream & guacamole, those are the big ticket items.

A Chipotle burrito is:

  Beans:                      120 cals, 22g carbs
  Tortilla:                   300 cals, 46g carbs
  Cheese + Sour Cream + Guac: 415 cals, 36g fat

http://www.chipotlecaloriecalculator.com

[shaftway]

Using net carbs (since you don't digest fiber), those beans drop to 12g of carbs. Also don't forget rice:

  Beans:   115 cals, 12g carbs
  Rice:    185 cals, 33g carbs

[pashapiro]

Thanks for the detailed answer!

The reason I asked about beans specifically was because, as I understand it, they're harder to digest. I'm guess the corn I see in the toilet doesn't leave many calories on my stomach either.

[jlebrech]

your body's ability to metabolize will increase too as you eat more. that's why skinny people who eat massively for a single meal once a week don't really gain weight, it's the regular over eating that does it.

[mod]

I don't think that's why. Those people would gain weight, but it's hard to "massively overeat" for one week to the tune of "noticeable amount."

You're talking 1 lb, maybe 2 if you really go overboard.

[mikeash]

A pound of fat is about 3,500 calories of overeating. Real hard to do that much in one sitting for someone who doesn't do it constantly.

[jlebrech]

3,500 calories of fat, or 30% extra of carbs or protein. protein is also insulinogenic so eating too much fat along with similar amounts of protein will make someone balloon (i.e fried chicken)

[ap3]

Yes but how much of those calories are you burning off every day ? - you would need 3,500 above your daily burn rate

[mikeash]

That's what I meant by "overeating": whatever is beyond what you need to sustain.

[twistedanimator]

You really shouldn't worry about the beans clinging to your thighs and gut. Nutritionally, beans are high in protein, have zero fat, and high in fiber. The beans are what will allow you to pass that burrito brick in the future.