please explain the problem with low calories...
Replies
-
Yes, a real, live doctor who has probably next to no nutritional training surely knows more about the dangers of eating too low calorie than someone who is actively recovering from an eating disorder who has multiple checkups A WEEK with several health care professionals who are HIGHLY specialized in the field. And monkeys might fly out my butt.I don't pay much attention to the number. I eat now WHEN I am hungry and I rarely come near the 1000 mark much LESS the 1200 or above. I am still losing, my trainer and Dr aren't upset, soooooooooooooooooo..It is a number
Good luck with the long term success of that strategy.... and fyi, your doctor and trainer may know *kitten* about nutrition. Your doctor for sure, and your trainer should know better-well so should the doctor but they don't usually take more than one course in nutrition in all their years of university. There are a whole bunch of Certified Personal Trainers right here on MFP that give the worst advice, and can't even get their own health in order.... So.
Pretty sure a real live doctor that you go to and have a patient/relationship with is a far better source on what is right for the individual than the advice of a thousand talking monkeys found on the innerwebz.
the problem here is you are assuming everyone is like you. 1000 calories a day isn't optimal but it's also not truely in the realm of very low calorie and it's not in any kind of eating disorder zone. Maybe that wouldn't be right for you. If someone is going to a doctor and being monitored and the doc has no problems with it then they're probably right.
sorry. the medical degree wins out over your history with eating disorders.0 -
At 1200, for most people, you're not eating enough. Your body goes into starvation mode, which then means it struggles to hold onto every single pound and it's harder for you to lose weight. When you do lose weight, it tends to be muscle mass, not fat. Bad all around.
This is NOT true. starvation mode isn't real.
the reason they state not to go under 1200 for most people is because of nutrients. most people cannot get the nutrients they need at a rate under that.
Here's the thing: technically, you are correct. MOST of the weight loss, meaning more than 50% does not come from muscle. HOWEVER, a much larger proportion of weight loss comes from eating at a low calorie diet than normal, like 25% to 30% of the total weight lost! VLCD also has many detrimental side effects regardless of your obesity level, but holding onto ALL of your fat isn't one of them. So yes, Starvation Mode is very real. No, it's not what most people think it is. That doesn't make it any less terrible or any less real.
For reference, see several studies I posted a few up.
1000 calories is not really what they'd call a vlcd. UNDER that is. Edited because webmd says it's under 800
http://www.webmd.com/diet/low-calorie-diets0 -
At 1200, for most people, you're not eating enough. Your body goes into starvation mode, which then means it struggles to hold onto every single pound and it's harder for you to lose weight. When you do lose weight, it tends to be muscle mass, not fat. Bad all around.
This is NOT true. starvation mode isn't real.
the reason they state not to go under 1200 for most people is because of nutrients. most people cannot get the nutrients they need at a rate under that.
So, wait - people shouldn't eat under 1200 calories because you won't get enough nutrients? If you're talking about micronutrients, it is impossible to survive on vitamins. If you're talking about macronutrients . . . well, that's just food.0 -
At 1200, for most people, you're not eating enough. Your body goes into starvation mode, which then means it struggles to hold onto every single pound and it's harder for you to lose weight. When you do lose weight, it tends to be muscle mass, not fat. Bad all around.
This is NOT true. starvation mode isn't real.
the reason they state not to go under 1200 for most people is because of nutrients. most people cannot get the nutrients they need at a rate under that.
Here's the thing: technically, you are correct. MOST of the weight loss, meaning more than 50% does not come from muscle. HOWEVER, a much larger proportion of weight loss comes from eating at a low calorie diet than normal, like 25% to 30% of the total weight lost! VLCD also has many detrimental side effects regardless of your obesity level, but holding onto ALL of your fat isn't one of them. So yes, Starvation Mode is very real. No, it's not what most people think it is. That doesn't make it any less terrible or any less real.
For reference, see several studies I posted a few up.
1000 calories is not really what they'd call a vlcd. UNDER that is.
Funny, one of the articles I mentioned explicitly mentioned under 1100 calories. 1000 is less than 1100 last time I checked. Of course, what with your medical degree from Harvard Medical, like, you know, the guy who approved this article, I'm sure you have a good reason for opinion.0 -
The conventional thinking is that you a) won't get enough nutrition, b) will cause your body to overwork in an unhealthy way, etc. but if you eat enough protein, take the right supplements and drink lots of water along with plenty of veggies -- you probably won't lose muscle mass. I spent the past three months on 1,000 calories a day and maintained 95% of my muscle mass but I had to take a ton of supplements and four cups of veggies plus protein shakes/bars for that to happen.0
-
Yes, a real, live doctor who has probably next to no nutritional training surely knows more about the dangers of eating too low calorie than someone who is actively recovering from an eating disorder who has multiple checkups A WEEK with several health care professionals who are HIGHLY specialized in the field. And monkeys might fly out my butt.I don't pay much attention to the number. I eat now WHEN I am hungry and I rarely come near the 1000 mark much LESS the 1200 or above. I am still losing, my trainer and Dr aren't upset, soooooooooooooooooo..It is a number
Good luck with the long term success of that strategy.... and fyi, your doctor and trainer may know *kitten* about nutrition. Your doctor for sure, and your trainer should know better-well so should the doctor but they don't usually take more than one course in nutrition in all their years of university. There are a whole bunch of Certified Personal Trainers right here on MFP that give the worst advice, and can't even get their own health in order.... So.
Pretty sure a real live doctor that you go to and have a patient/relationship with is a far better source on what is right for the individual than the advice of a thousand talking monkeys found on the innerwebz.
the problem here is you are assuming everyone is like you. 1000 calories a day isn't optimal but it's also not truely in the realm of very low calorie and it's not in any kind of eating disorder zone. Maybe that wouldn't be right for you. If someone is going to a doctor and being monitored and the doc has no problems with it then they're probably right.
sorry. the medical degree wins out over your history with eating disorders.
That's only true if the doctor knows what he/she is talking about on the given subject. I wouldn't go to a doctor who specializes in brain injuries for a sprained wrist either.0 -
the medical definition sure appears to be 800 or less
http://www.webmd.com/diet/low-calorie-diets
http://en.wikipedia.org/wiki/Very_low_calorie_diet
http://win.niddk.nih.gov/publications/low_calorie.htm0 -
Yes, a real, live doctor who has probably next to no nutritional training surely knows more about the dangers of eating too low calorie than someone who is actively recovering from an eating disorder who has multiple checkups A WEEK with several health care professionals who are HIGHLY specialized in the field. And monkeys might fly out my butt.I don't pay much attention to the number. I eat now WHEN I am hungry and I rarely come near the 1000 mark much LESS the 1200 or above. I am still losing, my trainer and Dr aren't upset, soooooooooooooooooo..It is a number
Good luck with the long term success of that strategy.... and fyi, your doctor and trainer may know *kitten* about nutrition. Your doctor for sure, and your trainer should know better-well so should the doctor but they don't usually take more than one course in nutrition in all their years of university. There are a whole bunch of Certified Personal Trainers right here on MFP that give the worst advice, and can't even get their own health in order.... So.
Pretty sure a real live doctor that you go to and have a patient/relationship with is a far better source on what is right for the individual than the advice of a thousand talking monkeys found on the innerwebz.
the problem here is you are assuming everyone is like you. 1000 calories a day isn't optimal but it's also not truely in the realm of very low calorie and it's not in any kind of eating disorder zone. Maybe that wouldn't be right for you. If someone is going to a doctor and being monitored and the doc has no problems with it then they're probably right.
sorry. the medical degree wins out over your history with eating disorders.
That's only true if the doctor knows what he/she is talking about on the given subject. I wouldn't go to a doctor who specializes in brain injuries for a sprained wrist either.
way to straw man it. a gp specializes in over all health and somehow that would be the reasonable assumption over someone going to a brain specialist for diet advice.0 -
Yes, a real, live doctor who has probably next to no nutritional training surely knows more about the dangers of eating too low calorie than someone who is actively recovering from an eating disorder who has multiple checkups A WEEK with several health care professionals who are HIGHLY specialized in the field. And monkeys might fly out my butt.I don't pay much attention to the number. I eat now WHEN I am hungry and I rarely come near the 1000 mark much LESS the 1200 or above. I am still losing, my trainer and Dr aren't upset, soooooooooooooooooo..It is a number
Good luck with the long term success of that strategy.... and fyi, your doctor and trainer may know *kitten* about nutrition. Your doctor for sure, and your trainer should know better-well so should the doctor but they don't usually take more than one course in nutrition in all their years of university. There are a whole bunch of Certified Personal Trainers right here on MFP that give the worst advice, and can't even get their own health in order.... So.
Pretty sure a real live doctor that you go to and have a patient/relationship with is a far better source on what is right for the individual than the advice of a thousand talking monkeys found on the innerwebz.
the problem here is you are assuming everyone is like you. 1000 calories a day isn't optimal but it's also not truely in the realm of very low calorie and it's not in any kind of eating disorder zone. Maybe that wouldn't be right for you. If someone is going to a doctor and being monitored and the doc has no problems with it then they're probably right.
sorry. the medical degree wins out over your history with eating disorders.
That's only true if the doctor knows what he/she is talking about on the given subject. I wouldn't go to a doctor who specializes in brain injuries for a sprained wrist either.
way to straw man it. a gp specializes in over all health and somehow that would be the reasonable assumption over someone going to a brain specialist for diet advice.
My gp is fat.
Seemed relevant to the discussion.0 -
It's not a straw man. It's hyperbole, which is not a logical fallacy. The point is that a GP specializes in nada by definition of "general". And the training that all medical students get is woefully inadequate. (It's the same problem with veterinarians.) It is absolutely not a reasonable assumption that they will be adequate for nutrition advice. You need to have more specialized knowledge for that, and most GPs just don't have it. You can pretend otherwise all you like, but that won't change the underlying fact of the matter.
Yes, a real, live doctor who has probably next to no nutritional training surely knows more about the dangers of eating too low calorie than someone who is actively recovering from an eating disorder who has multiple checkups A WEEK with several health care professionals who are HIGHLY specialized in the field. And monkeys might fly out my butt.I don't pay much attention to the number. I eat now WHEN I am hungry and I rarely come near the 1000 mark much LESS the 1200 or above. I am still losing, my trainer and Dr aren't upset, soooooooooooooooooo..It is a number
Good luck with the long term success of that strategy.... and fyi, your doctor and trainer may know *kitten* about nutrition. Your doctor for sure, and your trainer should know better-well so should the doctor but they don't usually take more than one course in nutrition in all their years of university. There are a whole bunch of Certified Personal Trainers right here on MFP that give the worst advice, and can't even get their own health in order.... So.
Pretty sure a real live doctor that you go to and have a patient/relationship with is a far better source on what is right for the individual than the advice of a thousand talking monkeys found on the innerwebz.
the problem here is you are assuming everyone is like you. 1000 calories a day isn't optimal but it's also not truely in the realm of very low calorie and it's not in any kind of eating disorder zone. Maybe that wouldn't be right for you. If someone is going to a doctor and being monitored and the doc has no problems with it then they're probably right.
sorry. the medical degree wins out over your history with eating disorders.
That's only true if the doctor knows what he/she is talking about on the given subject. I wouldn't go to a doctor who specializes in brain injuries for a sprained wrist either.
way to straw man it. a gp specializes in over all health and somehow that would be the reasonable assumption over someone going to a brain specialist for diet advice.0 -
It's not a straw man. It's hyperbole, which is not a logical fallacy. The point is that a GP specializes in nada by definition of "general". And the training that all medical students get is woefully inadequate. (It's the same problem with veterinarians.) It is absolutely not a reasonable assumption that they will be adequate for nutrition advice. You need to have more specialized knowledge for that, and most GPs just don't have it. You can pretend otherwise all you like, but that won't change the underlying fact of the matter.
Yes, a real, live doctor who has probably next to no nutritional training surely knows more about the dangers of eating too low calorie than someone who is actively recovering from an eating disorder who has multiple checkups A WEEK with several health care professionals who are HIGHLY specialized in the field. And monkeys might fly out my butt.I don't pay much attention to the number. I eat now WHEN I am hungry and I rarely come near the 1000 mark much LESS the 1200 or above. I am still losing, my trainer and Dr aren't upset, soooooooooooooooooo..It is a number
Good luck with the long term success of that strategy.... and fyi, your doctor and trainer may know *kitten* about nutrition. Your doctor for sure, and your trainer should know better-well so should the doctor but they don't usually take more than one course in nutrition in all their years of university. There are a whole bunch of Certified Personal Trainers right here on MFP that give the worst advice, and can't even get their own health in order.... So.
Pretty sure a real live doctor that you go to and have a patient/relationship with is a far better source on what is right for the individual than the advice of a thousand talking monkeys found on the innerwebz.
the problem here is you are assuming everyone is like you. 1000 calories a day isn't optimal but it's also not truely in the realm of very low calorie and it's not in any kind of eating disorder zone. Maybe that wouldn't be right for you. If someone is going to a doctor and being monitored and the doc has no problems with it then they're probably right.
sorry. the medical degree wins out over your history with eating disorders.
That's only true if the doctor knows what he/she is talking about on the given subject. I wouldn't go to a doctor who specializes in brain injuries for a sprained wrist either.
way to straw man it. a gp specializes in over all health and somehow that would be the reasonable assumption over someone going to a brain specialist for diet advice.
It was a strawman. taking a gp and turning them into a brain specialist is changing the argument and knocking it down based on the changes to the argument made.
Gps actually do specialize in the most common problems bought to them. Obesity being one of the number one illnesses we face today, I am pretty sure they're mostly well versed in it and well versed in how their patients are doing. Surely if they were actually in medical trouble that would kind of be showing up in their test results yeah?0 -
I eat 1100-1150.. 100 pro 125 carbs 25 fat..every day. Im losing consistently. From 232 to 138. My body is solid, i lift weights. Bench 105, dl 195, press 95. I can do 87 burpees in 7 minutes.... i run a 24 min 5k. Point- healthy and fit. Clearly dont require my bmr of 1437 or my tdee of 2675. I drop a lb a week. Goal 129.0
-
Yes, a real, live doctor who has probably next to no nutritional training surely knows more about the dangers of eating too low calorie than someone who is actively recovering from an eating disorder who has multiple checkups A WEEK with several health care professionals who are HIGHLY specialized in the field. And monkeys might fly out my butt.I don't pay much attention to the number. I eat now WHEN I am hungry and I rarely come near the 1000 mark much LESS the 1200 or above. I am still losing, my trainer and Dr aren't upset, soooooooooooooooooo..It is a number
Good luck with the long term success of that strategy.... and fyi, your doctor and trainer may know *kitten* about nutrition. Your doctor for sure, and your trainer should know better-well so should the doctor but they don't usually take more than one course in nutrition in all their years of university. There are a whole bunch of Certified Personal Trainers right here on MFP that give the worst advice, and can't even get their own health in order.... So.
Pretty sure a real live doctor that you go to and have a patient/relationship with is a far better source on what is right for the individual than the advice of a thousand talking monkeys found on the innerwebz.
the problem here is you are assuming everyone is like you. 1000 calories a day isn't optimal but it's also not truely in the realm of very low calorie and it's not in any kind of eating disorder zone. Maybe that wouldn't be right for you. If someone is going to a doctor and being monitored and the doc has no problems with it then they're probably right.
sorry. the medical degree wins out over your history with eating disorders.
That's only true if the doctor knows what he/she is talking about on the given subject. I wouldn't go to a doctor who specializes in brain injuries for a sprained wrist either.
way to straw man it. a gp specializes in over all health and somehow that would be the reasonable assumption over someone going to a brain specialist for diet advice.
It's not even worse than "he's a doctor so he's knowledgeable about anything involving health." I wouldn't go to someone with a broad and general understanding of health for something that requires specialization. That's why specialists exist.
Though for the sake of argument, I'll amend my statement to "I wouldn't go to a gp to diagnose a brain injury either." Happy now?0 -
Refreshing, isn't it. Good luck OP, you have the right attitude to be successful, and healthy.0
-
ok not a single person has backed up their claims either against or for eating at 1000 cal. Every one explains their science. Not one person, except the person who said abt the study where 1000 cal diet was advised for obese test volunteers. Come one people , If we are to have an eye opener , you should back up what you say . I have been searching for studies that show either way , but have not seen any. This would be a good thread to direct people to If we resolve it.
http://www.ncbi.nlm.nih.gov/pubmed/19198647
"CR results in a metabolic adaptation and a behavioral adaptation with decreased physical activity levels"
http://win.niddk.nih.gov/publications/low_calorie.htm
"Many patients on a VLCD for 4 to 16 weeks report minor side effects such as fatigue, constipation, nausea, or diarrhea. These conditions usually improve within a few weeks and rarely prevent patients from completing the program. The most
common serious side effect is gallstones."
http://www.itrim.se/Global/SE/PDF/Fordjupad-beskrivning/fordjupad_beskrivning.pdf (pg13)
The risk of developing gallstones was 3-fold greater for VLCD than those on LCD
http://ajcn.nutrition.org/content/53/4/826.full.pdf
Correlation of VLCD and RMR decrease after 21 days
http://ajcn.nutrition.org/content/45/2/391.full.pdf
This was a Study on Optifast, the participants consumes about 420 calories a day, and then were upped to 800 calories. There was an increased amount of cheating during a 5 week period. Also, RMR significantly dropped during the study, and remained lower even during the refeeding period. Energy Expenditures also decreased but increased when refeeding.
SCIENCE!
Granted, some of these studies are lower than 1,000 calories, but some of the things listed in these studies do happen at that level. Maybe not to everyone, but they do happen.0 -
If I told you I could reduce your weight, but to make it happen I would drill microscopic holes in your bones, so they would be a little more fragile, would you do it?
If I told you I could reduce your weight, but in exchange your metabolic process would slow down, so you would take longer to recover from illness and burn fewer calories each day, would you do it?
If i told you I could cut your weight, but in doing so you would probably experience long term damage to organs that may or may not amount to anything, would you risk it?
If I told you I could lower your weight, but you would have to give up some cognitive ability instead, would you do it?
Probably not. At least, I hope not. All of these things and more is what happens if you don't eat enough food. It won't happen in one week. It may not even happen in a month. But keep it up, and it will happen.
I love this...
Ditto.0 -
Well..I'll just give my input even thought I'm sure it won't be held up as much as everyone elses;
I have an eating disorder. I have to go to the doctor twice a week to watch my blood pressure, that runs around 70/50 because if it gets lower than that, something could go wrong with my heart and I could die. My pulse is also extremely low. My oxygen saturation is low. My body temperature runs around 96 (where a normal body temp is 98.6). I have to regularly get blood test to check and make sure that there is no damage to my kidneys or liver and a slew of other things (There is an order for blood work sitting right beside me right now, the orders on it are TSH, CBC, CMP (chem 14), ESR (Sed Rate), A1C) because what I have done to my body. How did I get said eating disorder? Eating less than 1000 calories a day. Dropping weight quickly. Deciding since I was dropping weight so quickly I would drop down more and more and more. Now my teeth are falling out, my hair is coming out in handfuls, and there is something wrong with my kidneys.
But good luck with your "healthy" low calorie diet.
Thank you for sharing this. I wish you the best.0 -
If I told you I could reduce your weight, but to make it happen I would drill microscopic holes in your bones, so they would be a little more fragile, would you do it?
If I told you I could reduce your weight, but in exchange your metabolic process would slow down, so you would take longer to recover from illness and burn fewer calories each day, would you do it?
If i told you I could cut your weight, but in doing so you would probably experience long term damage to organs that may or may not amount to anything, would you risk it?
If I told you I could lower your weight, but you would have to give up some cognitive ability instead, would you do it?
Probably not. At least, I hope not. All of these things and more is what happens if you don't eat enough food. It won't happen in one week. It may not even happen in a month. But keep it up, and it will happen.
I love this...
Ditto.
After I read the rest of the posts, kudos to the OP for being open-minded when reading the great advice she was given.
Yay OP and fairy tales do come true :drinker:0 -
Well..I'll just give my input even thought I'm sure it won't be held up as much as everyone elses;
I have an eating disorder. I have to go to the doctor twice a week to watch my blood pressure, that runs around 70/50 because if it gets lower than that, something could go wrong with my heart and I could die. My pulse is also extremely low. My oxygen saturation is low. My body temperature runs around 96 (where a normal body temp is 98.6). I have to regularly get blood test to check and make sure that there is no damage to my kidneys or liver and a slew of other things (There is an order for blood work sitting right beside me right now, the orders on it are TSH, CBC, CMP (chem 14), ESR (Sed Rate), A1C) because what I have done to my body. How did I get said eating disorder? Eating less than 1000 calories a day. Dropping weight quickly. Deciding since I was dropping weight so quickly I would drop down more and more and more. Now my teeth are falling out, my hair is coming out in handfuls, and there is something wrong with my kidneys.
But good luck with your "healthy" low calorie diet.
Thanks for sharing. I was heading toward this in my early 20's because a doctor - a young clueless one - told me that I was 25 lbs overweight at 155. My goal weight now is 150. I got down to 138 then went home for break from school and my mom dragged me to her doctor. HE saved my life. My body fat was 8%. I am, in fact, not eating enough now. I too often don't net 1300. Doing that for six weeks tomorrow has jump started my weight loss but this week I have felt tired and today I had to take a nap after work. I recognize the signs. My body is not burning only fat now. Time to fix it...
Eat more, OP. It's the healthy way to do it.0 -
*0
-
Why do people just try and ignore the science?0
-
It's not a straw man. It's hyperbole, which is not a logical fallacy. The point is that a GP specializes in nada by definition of "general". And the training that all medical students get is woefully inadequate. (It's the same problem with veterinarians.) It is absolutely not a reasonable assumption that they will be adequate for nutrition advice. You need to have more specialized knowledge for that, and most GPs just don't have it. You can pretend otherwise all you like, but that won't change the underlying fact of the matter.
Yes, a real, live doctor who has probably next to no nutritional training surely knows more about the dangers of eating too low calorie than someone who is actively recovering from an eating disorder who has multiple checkups A WEEK with several health care professionals who are HIGHLY specialized in the field. And monkeys might fly out my butt.I don't pay much attention to the number. I eat now WHEN I am hungry and I rarely come near the 1000 mark much LESS the 1200 or above. I am still losing, my trainer and Dr aren't upset, soooooooooooooooooo..It is a number
Good luck with the long term success of that strategy.... and fyi, your doctor and trainer may know *kitten* about nutrition. Your doctor for sure, and your trainer should know better-well so should the doctor but they don't usually take more than one course in nutrition in all their years of university. There are a whole bunch of Certified Personal Trainers right here on MFP that give the worst advice, and can't even get their own health in order.... So.
Pretty sure a real live doctor that you go to and have a patient/relationship with is a far better source on what is right for the individual than the advice of a thousand talking monkeys found on the innerwebz.
the problem here is you are assuming everyone is like you. 1000 calories a day isn't optimal but it's also not truely in the realm of very low calorie and it's not in any kind of eating disorder zone. Maybe that wouldn't be right for you. If someone is going to a doctor and being monitored and the doc has no problems with it then they're probably right.
sorry. the medical degree wins out over your history with eating disorders.
That's only true if the doctor knows what he/she is talking about on the given subject. I wouldn't go to a doctor who specializes in brain injuries for a sprained wrist either.
way to straw man it. a gp specializes in over all health and somehow that would be the reasonable assumption over someone going to a brain specialist for diet advice.
It was a strawman. taking a gp and turning them into a brain specialist is changing the argument and knocking it down based on the changes to the argument made.
Gps actually do specialize in the most common problems bought to them. Obesity being one of the number one illnesses we face today, I am pretty sure they're mostly well versed in it and well versed in how their patients are doing. Surely if they were actually in medical trouble that would kind of be showing up in their test results yeah?
You said it all right there: GENERAL. My cousin is actually a doc. A specialist in Oncology. And he had to go to school for years extra to be a Specialist. It's the same for anyone in the medical field. A GP is just that -- a GP. If you went in on a 1000 cal diet with all of these symptoms, he would run tests and then send you on to a specialist. If you go in fat, they send you to a specialist -- either a Dietician or a Nutritionist. Which is what happened to my Dad. The doc gave NO advice. He said, "Well, Mr. So and So, you're fat. So, we need to send you on to a Nutritionist to get you on the right track." So, while a GP may think it it is healthier short term to get some weight off right now if the patient was morbidly obese, it's HIGHLY unlikely that the same GP would be so gung ho for such a drastic cut for a small or moderate amount of weight. Why? Because it isn't moderate and it isn't sustainable long term. And BTW, I would say that most GP's are so busy they rarely have the time to cover EVERY SINGLE PIECE of research that comes out. It is up to us to do the research for our own health.
ETA: Edited for grammar. I suck. LOL0 -
Actually it is ok... I am 5'7'' with 90 lbs I only need 1300 per day.. which is normal0
-
Actually, your brain doesn't use fat at all. It's strictly a glycogen consumer. And since it can't store glycogen on its own it taps into the approx 30g of glycogen stored in your liver to provide fuel.When you net less than your BMR, your brain is unable to use fat stores from your body. It must convert lean muscle mass into energy so it can run, and your brain uses more calories than you think.
At least, that's what I found out a year ago when I did a search for "What does the brain use for energy."
Please cite medical reference, I wish to learn.
http://en.wikipedia.org/wiki/Starvation_response
"In humans
Starvation mode is a state in which the body is responding to prolonged periods of low energy intake levels. During short periods of energy abstinence, the human body will burn primarily free fatty acids from body fat stores. After prolonged periods of starvation the body has depleted its body fat and begins to burn lean tissue and muscle as a fuel source.[2]
Ordinarily, the body responds to reduced energy intake by burning fat reserves first, and only consumes muscle and other tissues when those reserves are exhausted. Specifically, the body burns fat after first exhausting the contents of the digestive tract along with glycogen reserves stored in muscle and liver cells.[3] After prolonged periods of starvation, the body will utilize the proteins within muscle tissue as a fuel source. People who practice fasting on a regular basis, such as those adhering to energy restricted diets, can prime their bodies to abstain from food while reducing the amount of muscle burned.[4] Resistance training (such as weight lifting) can also prevent the loss of muscle mass while a person is energy-restricted.
Magnitude and composition
The magnitude and composition of the starvation response (i.e. metabolic adaptation) was estimated in a study of 8 individuals living in isolation in Biosphere 2 for two years. During their isolation, they gradually lost an average of 15% (range: 9–24%) of their body weight due to harsh conditions. On emerging from isolation, the eight isolated individuals were compared with a 152-person control group that initially had had similar physical characteristics. On average, the starvation response of the individuals after isolation was a 180 kcal reduction in daily total energy expenditure. 60 kcal of the starvation response was explained by a reduction in fat-free mass and fat mass. An additional 65 kcal was explained by a reduction in fidgeting, and the remaining 55 kcal was statistically insignificant.[5]
Process
General
The energetic requirements of a body are composed of the basal metabolic rate and the physical activity level. This caloric requirement can be met with protein, fat, carbohydrates or a mixture of them. Glucose is the general metabolic fuel, which can be metabolized by any cell. Fructose and some other nutrients can only be metabolized in the liver, where their metabolites are transformed either into glucose and stored as glycogen, both in the liver and in the muscles; or into fatty acids which are stored in adipose tissue.
Because of the blood–brain barrier, getting nutrients to the human brain is especially dependent on molecules that can pass this barrier. The brain itself consumes about 18% of the basal metabolic rate: on a total intake of 1800 kcal/day, this equates to 324 kcal, or about 80 g of glucose. About 25% of total body glucose consumption occurs in the brain.
Glucose can be obtained directly from dietary sugars and by the breakdown of other carbohydrates. In the absence of dietary sugars and carbohydrates, glucose is obtained from the breakdown of stored glycogen. Glycogen is a readily-accessible storage form of glucose, stored in notable quantities in the liver and in small quantities in the muscles. The body's glycogen reserve is enough to provide glucose for about 24 hours.[citation needed]
When the glycogen reserve is depleted, glucose can be obtained from the breakdown of fats from adipose tissue. Fats are broken down into glycerol and free fatty acids, with the glycerol being utilized in the liver as a substrate for gluconeogenesis.
When even the glycerol reserves are depleted, or sooner, the liver will start producing ketone bodies. Ketone bodies are short-chain derivatives of fatty acids, which, since they are capable of crossing the blood–brain barrier, can be used by the brain as an alternative metabolic fuel. Fatty acids can be used directly as an energy source by most tissues in the body.
Timeline
After the exhaustion of the glycogen reserve, and for the next 2–3 days, fatty acids are the principal metabolic fuel. At first, the brain continues to use glucose, because, if a non-brain tissue is using fatty acids as its metabolic fuel, the use of glucose in the same tissue is switched off. Thus, when fatty acids are being broken down for energy, all of the remaining glucose is made available for use by the brain.
After 2 or 3 days of fasting, the liver begins to synthesize ketone bodies from precursors obtained from fatty acid breakdown. The brain uses these ketone bodies as fuel, thus cutting its requirement for glucose. After fasting for 3 days, the brain gets 30% of its energy from ketone bodies. After 4 days, this goes up to 70%.
Thus, the production of ketone bodies cuts the brain's glucose requirement from 80 g per day to about 30 g per day. Of the remaining 30 g requirement, 20 g per day can be produced by the liver from glycerol (itself a product of fat breakdown). But this still leaves a deficit of about 10 g of glucose per day that must be supplied from some other source. This other source will be the body's own proteins.
After several days of fasting, all cells in the body begin to break down protein. This releases amino acids into the bloodstream, which can be converted into glucose by the liver. Since much of our muscle mass is protein, this phenomenon is responsible for the wasting away of muscle mass seen in starvation.
However, the body is able to selectively decide which cells will break down protein and which will not. About 2–3 g of protein has to be broken down to synthesize 1 g of glucose; about 20–30 g of protein is broken down each day to make 10 g of glucose to keep the brain alive. However, this number may decrease the longer the fasting period is continued in order to conserve protein.
Starvation ensues when the fat reserves are completely exhausted and protein is the only fuel source available to the body. Thus, after periods of starvation, the loss of body protein affects the function of important organs, and death results, even if there are still fat reserves left unused. (In a leaner person, the fat reserves are depleted earlier, the protein depletion occurs sooner, and therefore death occurs sooner.)
The ultimate cause of death is, in general, cardiac arrhythmia or cardiac arrest brought on by tissue degradation and electrolyte imbalances.
Timeline
0 hours: Glycoes still used as primary fuel.
0 – 6 hours: Glycogen is broken down to produce glucose for the body.
6 – 72 hours: Glycogen stores are used up and the body breaks down fatty acids. Ketone bodies are produced to help feed the brain.
The body's rate of protein loss is greatest during the first 72 hours. After several days of starvation the body adapts and starts to conserve protein.[6]
Biochemistry
The human starvation response is unique among animals in that human brains do not require the ingestion of glucose to function. During starvation, less than half the energy used by the brain comes from metabolized glucose. Because the human brain can use ketone bodies as major fuel sources, the body is not forced to break down skeletal muscles at a high rate, thereby maintaining both cognitive function and mobility for up to several weeks. This response is extremely important in human evolution and allowed for humans to continue to find food effectively even in the face of prolonged starvation.[7]
Initially, the level of insulin in circulation drops and the levels of glucagon and epinephrine rise, degrading high amounts of glycogen and upregulating gluconeogenesis, lipolysis, and ketogenesis. The body’s glycogen stores are consumed in about 24 hours. In a normal 70 kg adult, only about 8,000 kilojoules of glycogen are stored in the body (mostly in the striated muscles).The body also engages in gluconeogenesis in order to convert glycerol and glucogenic amino acids into glucose for metabolism. Another adaptation is the Cori cycle, which involves shuttling lipid-derived energy in glucose to peripheral glycolytic tissues, which in turn send the lactate back to the liver for resynthesis to glucose. Because of these processes, blood glucose levels will remain relatively stable during prolonged starvation.
However, the main source of energy during prolonged starvation is derived from triglycerides. Compared to the 8,000 kilojoules of stored glycogen, lipid fuels are much richer in energy content, and a 70 kg adult will store over 400,000 kilojoules of triglycerides (mostly in adipose tissue).[8] Triglycerides are broken down to fatty acids via lipolysis. Epinephrine precipitates lipolysis by activating protein kinase A, which phosphorylates hormone sensitive lipase (HSL) and perilipin. These enzymes, along with CGI-58 and adipose triglyeride lipase (ATGL), complex at the surface of lipid droplets. The concerted action of ATGL and HSL liberates the first two fatty acids. Cellular monoacylglycerol lipase (MGL), liberates the final fatty acid. The remaining glycerol enters gluconeogenesis.[9]
Fatty acids by themselves cannot be used as a direct fuel source. They must first undergo beta oxidation in the mitochondria (mostly of skeletal muscle, cardiac muscle, and liver cells). Fatty acids are transported into the mitochondria as an acyl-carnitine via the action of the enzyme CAT-1. This step controls the metabolic flux of beta oxidation. The resulting acetyl-CoA enters the TCA cycle and undergoes oxidative phosphorylation to produce ATP. Some of this ATP is invested in gluconeogenesis in order to produce more glucose.[10]
Triglycerides and long-chain fatty acids are too hydrophobic to cross into brain cells, so the liver must convert them into short-chain fatty acids and ketone bodies through ketogenesis. The resulting ketone bodies, acetoacetate and β-hydroxybutyrate, are amphipathic and can be transported into the brain (and muscles) and broken down into acetyl-CoA for use in the TCA cycle. Acetoacetate breaks down spontaneously into acetone, and the acetone is released through the urine and lungs to produce the “acetone breath” that accompanies prolonged fasting. The brain also uses glucose during starvation, but most of the body’s glucose is allocated to the skeletal muscles and red blood cells. The cost of the brain using too much glucose is muscle loss. If the brain and muscles relied entirely on glucose, the body would lose 50% of its nitrogen content in 8–10 days.[11]
After prolonged fasting, the body begins to degrade its own skeletal muscle. In order to keep the brain functioning, gluconeogenesis will continue to generate glucose, but glucogenic amino acids, primarily alanine, are required. These come from the skeletal muscle. Late in starvation, when blood ketone levels reach 5-7 mM, ketone use in the brain rises, while ketone use in muscles drops.[12]
Autophagy then occurs at an accelerated rate. In autophagy, cells will cannibalize critical molecules to produce amino acids for gluconeogenesis. This process distorts the structure of the cells, and a common cause of death in starvation is due to diaphragm failure from prolonged autophagy.[13]"0 -
You make no gaiinz.0
-
How long have you been eating 1000? It may be okay for a little while, but eventually your body will suffer. If you start incorporating exercise, you will quite likely start being hungry for more.0
-
It's not a straw man. It's hyperbole, which is not a logical fallacy. The point is that a GP specializes in nada by definition of "general". And the training that all medical students get is woefully inadequate. (It's the same problem with veterinarians.) It is absolutely not a reasonable assumption that they will be adequate for nutrition advice. You need to have more specialized knowledge for that, and most GPs just don't have it. You can pretend otherwise all you like, but that won't change the underlying fact of the matter.
Yes, a real, live doctor who has probably next to no nutritional training surely knows more about the dangers of eating too low calorie than someone who is actively recovering from an eating disorder who has multiple checkups A WEEK with several health care professionals who are HIGHLY specialized in the field. And monkeys might fly out my butt.I don't pay much attention to the number. I eat now WHEN I am hungry and I rarely come near the 1000 mark much LESS the 1200 or above. I am still losing, my trainer and Dr aren't upset, soooooooooooooooooo..It is a number
Good luck with the long term success of that strategy.... and fyi, your doctor and trainer may know *kitten* about nutrition. Your doctor for sure, and your trainer should know better-well so should the doctor but they don't usually take more than one course in nutrition in all their years of university. There are a whole bunch of Certified Personal Trainers right here on MFP that give the worst advice, and can't even get their own health in order.... So.
Pretty sure a real live doctor that you go to and have a patient/relationship with is a far better source on what is right for the individual than the advice of a thousand talking monkeys found on the innerwebz.
the problem here is you are assuming everyone is like you. 1000 calories a day isn't optimal but it's also not truely in the realm of very low calorie and it's not in any kind of eating disorder zone. Maybe that wouldn't be right for you. If someone is going to a doctor and being monitored and the doc has no problems with it then they're probably right.
sorry. the medical degree wins out over your history with eating disorders.
That's only true if the doctor knows what he/she is talking about on the given subject. I wouldn't go to a doctor who specializes in brain injuries for a sprained wrist either.
way to straw man it. a gp specializes in over all health and somehow that would be the reasonable assumption over someone going to a brain specialist for diet advice.
It was a strawman. taking a gp and turning them into a brain specialist is changing the argument and knocking it down based on the changes to the argument made.
Gps actually do specialize in the most common problems bought to them. Obesity being one of the number one illnesses we face today, I am pretty sure they're mostly well versed in it and well versed in how their patients are doing. Surely if they were actually in medical trouble that would kind of be showing up in their test results yeah?
You said it all right there: GENERAL. My cousin is actually a doc. A specialist in Oncology. And he had to go to school for years extra to be a Specialist. It's the same for anyone in the medical field. A GP is just that -- a GP. If you went in on a 1000 cal diet with all of these symptoms, he would run tests and then send you on to a specialist. If you go in fat, they send you to a specialist -- either a Dietician or a Nutritionist. Which is what happened to my Dad. The doc gave NO advice. He said, "Well, Mr. So and So, you're fat. So, we need to send you on to a Nutritionist to get you on the right track." So, while a GP may think it it is healthier short term to get some weight off right now if the patient was morbidly obese, it's HIGHLY unlikely that the same GP would be so gung ho for such a drastic cut for a small or moderate amount of weight. Why? Because it isn't moderate and it isn't sustainable long term. And BTW, I would say that most GP's are so busy they rarely have the time to cover EVERY SINGLE PIECE of research that comes out. It is up to us to do the research for our own health.
ETA: Edited for grammar. I suck. LOL
I am in medical school right now, and let me tell you, nutrition is NOT part of the standard curriculum. We do get training in motivational interviewing - basically how to get buy in from patients on lifestyle changes - but we don't really talk about setting up nutrition plans for people and things like that. We refer out to certified nutrition professionals and diabetes educators because of this, and if your doc gives you some random number, be suspicious unless they are in bariatrics or have some other additional training. I have been seeking additional training outside the curriculum so I can better support my patients, but I would still be uncomfortable setting up a whole plan for them - in part because that is not what I am trained for. I would love to see nutritional training become more wide spread in medical schools, but frankly we are all so busy learning how to put out fires RIGHT NOW that we don't have a moment to consider where the tinder is coming from.0 -
Thanks for all this info. I started reading and could not stop. I quickly got to googling and am for sure raising my calories. I think I might have started over doing it. I want to have the energy to do the exercise!0
-
was going to write info but instead ill just use this sense its the best thing ever written on this subject.It's sort of like the problem with low Oxygen. Do you really want to find out where that limit is, and to discover the damage that's done to your mind and body along the way? Or would it perhaps be better to ensure you get plenty of Oxygen without hyperventilating?
but also read this topic.
http://www.myfitnesspal.com/topics/show/761810-the-starvation-mode-myth-again0 -
was going to write info but instead ill just use this sense its the best thing ever written on this subject.It's sort of like the problem with low Oxygen. Do you really want to find out where that limit is, and to discover the damage that's done to your mind and body along the way? Or would it perhaps be better to ensure you get plenty of Oxygen without hyperventilating?
but also read this topic.
http://www.myfitnesspal.com/topics/show/761810-the-starvation-mode-myth-again
I'm confused. I read that thread when it was first posted last year and I believe the general consensus in it supported the "low oxygen" analogy above. This thread here isn't an argument about the existence or prevalence of "starvation mode", but a discussion of the potential problems associated with eating too little. There's a difference. Don't get hung up on the label but look through to the lasting consequences of cutting calories too low for too long.0
This discussion has been closed.
Categories
- All Categories
- 1.4M Health, Wellness and Goals
- 393.4K Introduce Yourself
- 43.8K Getting Started
- 260.2K Health and Weight Loss
- 175.9K Food and Nutrition
- 47.4K Recipes
- 232.5K Fitness and Exercise
- 426 Sleep, Mindfulness and Overall Wellness
- 6.5K Goal: Maintaining Weight
- 8.5K Goal: Gaining Weight and Body Building
- 153K Motivation and Support
- 8K Challenges
- 1.3K Debate Club
- 96.3K Chit-Chat
- 2.5K Fun and Games
- 3.7K MyFitnessPal Information
- 24 News and Announcements
- 1.1K Feature Suggestions and Ideas
- 2.6K MyFitnessPal Tech Support Questions