How do calories get inside your body?

**gYmgIrL** · August 25th, 2008, 02:08 AM

Hi!

I was wondering about random things, as you do, and i got to thinking, when in the digestion process do you get the calories/energy out of the food?

so i looked it up and still dont know

some say it's through your mouth (what about the bulemics?)

and some say that annorexic people take laxitives to reduce the calories, which would mean that they get taken out through the bowel!

Anyone here good at human bio?

Its interesting!

**JoeBAR** · August 25th, 2008, 03:05 AM

it actually varies, depending on digestion time. most transfers are done in the intestine.

saliva breaks down starch into glucose (chew white bread for 2 min, it becomes sweet)
gastric suc in stomach finishes that off and also sorts out proteins and various minerals it also starts phat digestions
in the first intestine, the bile and pancreas suc finish off the breakdown of complex food molecules into basic molecules (glucose, amino acids etc).

glucose is the body's fuel, and the only form of energy it really uses (phat is converted into glucose too). In extreme cases, amino acids are used, but let's leave that for now. glucose is what the body uses for calories and they enter the blood through the intestine wall as soon as they're down to 1 molecule size (I simplify, I know). Same for amino acids, vitamins, minerals... amino acids are used to make cells, glucose to burn as energy (if there is an excess in glucose, it is stored as phat - hence phat don't come from the phat you eat but from excess sugar. it's related since phat is converted by the system into sugar, but it's not phat -> phat... Hence low sugar diet are as efficient if not more than low phat diet, considering the extra effort, and energy, needed to digest phat).

anorexics take laxative which makes the food travel whole through their bowel and they pass it undigested, or mostly undigested. Phat don't get broken down especially, and little proteins too, so they have a very low actual calorie absorption. No point eating food if you shit it whole, really, is it? It's a rather unhealthy process and can cause serious damage to the big intestine and anus.

bulimics are people who "need" to eat. Basically, when you've had enough, there's a little buddy in your stomach who tells the boss in your brain it's had enough, so the boss tell the mouth to quit

For bulimics, the little buddy in the stomach is off sick, or off on strike. So they just keep eating, preferably sugars coz it's nice to eat sugars and sugars don't wake up the little buddy either, just in case it felt like coming back to work.

**sucher67** · August 25th, 2008, 08:47 AM

Hello all,

I just want to be sure to emphasise, that calories are a measurement of energy. That is all. (Gymgirl mentioned anorexic and bulemics behaviour-- they are attempting to control the energy absorbed by their bodies by purging or avoiding food.)

Also, food laboratories calculate food calories by burning the food. Really. So, when you look at calories, you are trying to assess the energy value of your food. Basically, food energy can come in the forms of fats and carbohydrates. However, fats and carbohydrates come in many forms.

As you know, processed foods tend to be more refined, so you get more energy from smaller amounts of them. A good goal is to get the maximum amount of nutrition per calorie. For example, a cola has a lot of calories (energy) but no nutirion. Steamed brocolli has very few calories but tons of nutrition. If you want to stay lean and eat well, guess which one is better?

To specifically answer Gymgirl's question-- Digestion begins in the mouth, but actual energy absorbtion occurs in the intestine.

**wildstang** · August 25th, 2008, 01:06 PM

various stages of absorbtion throughout the intestines. some is absorbed in the small intestines were certain things such as water is absorbed in the large intestine 4 example.

**tooncesthecat** · August 25th, 2008, 06:27 PM

FOOD>>>>>DIGESTION>>>>>>>TINY PARTS (GLUCOSE, FATTY ACIDS, PROTEINS)>>>>>>GLUCOSE FOR ENERGY, FATTY ACIDS FOR STORED ENERGY AND BUILDING CELLS, PROTEINS FOR BUILDING BODY PARTS AND OTHER STUFF.

Extra calories (energy) gets stored for a rainy day! Calories can come from proteins, fats, and carbohydrates but the body especially likes carbohydrates!

**gYmgIrL** · August 26th, 2008, 08:34 AM

Oh I see, so if you had a bad bought of stomach problems you could easily lose muscle in a small space of time.

**tooncesthecat** · August 26th, 2008, 06:31 PM

Depending on the stomach problem you could have trouble with protein absorption. Pepsin is a digestive enzyme which breaks down proteins in the stomach. The protein needs to be broken down so it can be absorbed in the small intestine after it leaves the stomach. If someone has problems with the small intestine they could also have absorption problems.

**JoeBAR** · August 26th, 2008, 11:55 PM

Quote:

Originally Posted by gYmgIrL

Oh I see, so if you had a bad bought of stomach problems you could easily lose muscle in a small space of time.

You'd have to be really bad. One don't loose much muscle for not training for 3 weeks, one wouldn't loose muscle for a couple of days of "runs". That said, past a number of days, weight start droping quite easily.

Dad had a few problem with his gall bladder and then a pancreas cancer earlier this year. On drip for 8 weeks, he lost about 30 lbs