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TOPIC: When are calories absorbed?

 
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February 22, 2010 9:54 AM
I just wanted to know how calorie absorption works. And also how long does it really take for the whole calorie counting thing and exercise to show results of weight loss 1 week 2 maybe?
  651509
February 22, 2010 10:17 AM
I am not a doctor, nor a nutritionist, nor a physical trainer. But I have been reading a lot in my journey. Here are some things I learned that might help.

1. Calories are a unit of energy, specifically heat energy. Your body uses energy to keep itself going, so you are always burning calories. MFP uses a guess at how many calories your body burns when doing absolutely nothing, but lying in bed, breathing. That number is called your Basal Metabolic Rate (BMR). You can go to the tools tab and calculate what your BMR is.

2. The number I have seen thrown around states that 1 lb of body mass (I don't know if it is only for fat, or for lean mass too) is equal to 3500 calories.

So, if you have the basic equation: Calories in - calories burned [(BMR) + exercise] = calorie deficit/surplus
- if you have 3500 calories per week deficit, you will lose 1 lb per week
- if you have 3500 calories per week surplus, you will gain 1 lb per week
Therefore, to lose 1 lb per week, you want your calorie deficit to be 500 calories per day (3500/7=500)

3. Your body wants to protect itself. If you do not intake enough calories to sustain itself (BMR) your body will go into starvation mode. When in starvation mode, your body will try to retain the fat because the body doesn't know when it will get energy next.

So, you will see a debate regarding eating exercise calories, or not. The debate is not limited to just MFP members, but it is raging among professional dieticians and physical trainers. I suspect the true answer lies in the individual, their BMR, and their caloric deficit/surplus.



So, long story short, your body has always been burning calories. As soon as you begin maintaining a calorie deficit, you will begin to see weight loss. The size of the calorie deficit will determine how fast you loose weight. My recommendation would be do not weigh yourself more than 1 time a week, or even every two weeks. Dutifully track your food intake, and don't cheat yourself on this count. Finally, get yourself a heart rate monitor to accurately record how many calories you burn when you exercise. After that, hang in there, and don't quit.
  378439
February 22, 2010 10:19 AM
A calorie isn't a "thing" to be absorbed. Strictly speaking, a calorie is a unit of heat equal to the amount of heat required to raise the temperature of one kilogram of water by one degree at one atmosphere pressure (ie, a measure of energy). In terms of nutrition, a calorie is how much energy is required to metabolize a given amount of foodstuffs.

You start the nutrient absorption process as soon as you eat. Certain foods are digested and absorbed in the stomach, others in the different parts (duodenum, jejunum, ileum) of the small intestine. The large intestine mostly absorbs water.

I hope this answers your question.
February 22, 2010 10:21 AM
It generally takes a deficit of 3500 cal to lose a pound. If you eat at a 500 a day deficit, that = 1 lb a week lost. Nutrient absorbtion occurs in the small intestine, for the most part, and that takes about 3 hours to start after you eat. Food spends about 2-3 hours in the stomach being broken down to absorbable molecules(Mechanical and chemical digestion)before it passes into the small intestine for absorption of it's nutrients.
  574206
February 22, 2010 10:23 AM
QUOTE:

I am not a doctor, nor a nutritionist, nor a physical trainer. But I have been reading a lot in my journey. Here are some things I learned that might help.

1. Calories are a unit of energy, specifically heat energy. Your body uses energy to keep itself going, so you are always burning calories. MFP uses a guess at how many calories your body burns when doing absolutely nothing, but lying in bed, breathing. That number is called your Basal Metabolic Rate (BMR). You can go to the tools tab and calculate what your BMR is.

2. The number I have seen thrown around states that 1 lb of body mass (I don't know if it is only for fat, or for lean mass too) is equal to 3500 calories.

So, if you have the basic equation: Calories in - calories burned [(BMR) + exercise] = calorie deficit/surplus
- if you have 3500 calories per week deficit, you will lose 1 lb per week
- if you have 3500 calories per week surplus, you will gain 1 lb per week
Therefore, to lose 1 lb per week, you want your calorie deficit to be 500 calories per day (3500/7=500)

3. Your body wants to protect itself. If you do not intake enough calories to sustain itself (BMR) your body will go into starvation mode. When in starvation mode, your body will try to retain the fat because the body doesn't know when it will get energy next.

So, you will see a debate regarding eating exercise calories, or not. The debate is not limited to just MFP members, but it is raging among professional dieticians and physical trainers. I suspect the true answer lies in the individual, their BMR, and their caloric deficit/surplus.



So, long story short, your body has always been burning calories. As soon as you begin maintaining a calorie deficit, you will begin to see weight loss. The size of the calorie deficit will determine how fast you loose weight. My recommendation would be do not weigh yourself more than 1 time a week, or even every two weeks. Dutifully track your food intake, and don't cheat yourself on this count. Finally, get yourself a heart rate monitor to accurately record how many calories you burn when you exercise. After that, hang in there, and don't quit.


Loving the input! Nice way of putting things!glasses
  245327
February 22, 2010 11:12 AM
Thank you flowerforyou
  651509

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