Why are so many agains low calorie and VLC dieting?

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Replies

  • WalkingAlong
    WalkingAlong Posts: 4,926 Member
    Here is an interesting article that answers your question as to why eating a VLCD is a bad idea. You are not giving your body the fuel it needs to function properly.

    http://www.bodyrecomposition.com/research-review/dissecting-the-energy-needs-of-the-body-research-review.html


    As you can see in the chart organs needs a minimum to function properly, in the "average" human the following figures are used:

    Liver 200
    Brain 240
    Heart 400
    Kidneys 400

    As you can see in just these 4 organs the average person needs to consume 1240 calories a day to allow normal organ function. Its up to you whether or not to believe it, or even care; this was just to answer your questions.

    TL;DR - Because its not necessary and can be dangerous.
    But does it say anywhere in there that your body needs those 1240 calories from TODAY's food? I think it's understood that bodies use stored fat calories to fuel deficits.

    Even Lyle has a very low calorie diet plan. It goes down to below 800 calories, I believe.

    No it doesn't but if you are eating under 1200 calories a day for an extended period of time where do you expect to get the fuel from? I didn't write the article but I understand that eating a VLCD is a bad idea.... and who is Lyle?
    Lyle McDonald, the author of that blog you linked to.

    You get the fuel from the fat you're trying to burn off in the first place. People without excess body fat to lose of course should not do VLCD.

    The point of that article has nothing to do with VLCD. It's "the idea that skeletal muscle burns massive numbers of calories would appear to be 100% incorrect." Which is another big MFP myth: "Build muscle to increase your RMR!"
  • _Resolve_
    _Resolve_ Posts: 735 Member
    Here is an interesting article that answers your question as to why eating a VLCD is a bad idea. You are not giving your body the fuel it needs to function properly.

    http://www.bodyrecomposition.com/research-review/dissecting-the-energy-needs-of-the-body-research-review.html


    As you can see in the chart organs needs a minimum to function properly, in the "average" human the following figures are used:

    Liver 200
    Brain 240
    Heart 400
    Kidneys 400

    As you can see in just these 4 organs the average person needs to consume 1240 calories a day to allow normal organ function. Its up to you whether or not to believe it, or even care; this was just to answer your questions.

    TL;DR - Because its not necessary and can be dangerous.
    But does it say anywhere in there that your body needs those 1240 calories from TODAY's food? I think it's understood that bodies use stored fat calories to fuel deficits.

    Even Lyle has a very low calorie diet plan. It goes down to below 800 calories, I believe.

    No it doesn't but if you are eating under 1200 calories a day for an extended period of time where do you expect to get the fuel from? I didn't write the article but I understand that eating a VLCD is a bad idea.... and who is Lyle?
    Lyle McDonald, the author of that blog you linked to.

    You get the fuel from the fat you're trying to burn off in the first place. People without excess body fat to lose of course should not do VLCD.

    I didn't make the connection with the Lyle reference, I cant comment on his eating habits. Again, what I do know is eating less calories than your body needs to function is a bad idea.


    Also I understand the point of that article has nothing to do with VLCD i was trying to be HELPFUL and demonstrate what calories your body needs to function.

    Why are you trying to troll?
  • acorsaut89
    acorsaut89 Posts: 1,147 Member
    I see a lot of threads like this one: http://www.myfitnesspal.com/topics/show/1342871-lowered-calorie-goal-and-need-help-staying-full

    Someone posts saying they are eating 1200 kcal/d, and a bunch of folks jump in saying not to do that. Why? Low calorie (LC) dieting and very low calorie (VLC) dieting are completely legitimate approaches to fighting obesity:

    http://www.win.niddk.nih.gov/publications/low_calorie.htm

    In my opinion, an obese person eating far below what someone else thinks they need to eat to lose weight - and to be honest, no one can be sure what someone else's caloric threshold for weight loss will be - should be: 1) encouraged to obtain the help of a weight loss program, and for VLC, proper medical surveillance; 2) advised that rapid weight loss may not be the best long term approach for everyone; but certainly not scolded or told that this approach is unequivocally wrong.

    The reason bariatric surgery helps so many people is that it makes it easier for them to do a VLC diet and diminishes the likelihood of early and substantial weight gain. With proper education and support, some people have success with a VLC or LC diet without doing surgery. It is not the right approach for everyone, but then what is?


    Well the biggest reason that comes to my mind is that with rapid loss you will lose weight yes but what's the weight made up of that you lose? It's not just fat, it's LBM too, essentially muscle.

    WLS patients are on a diet of mostly protein so they can maintain as much muscle as possible because doctors have learned, from experience I imagine, that this kind of sudden weight loss can have damaging effects on the human body.

    Also, it's usually a "get skinny quick" thing and people don't want to put in the effort to realize what it takes to get to your goal - it isn't just about starving yourself because I can say that I haven't starved once during my journey. It's like expecting to go the distance of a full tank of gas when you only filled it up half way. Eating these very low calorie diets is ridiculous and it usually doesn't get you anywhere in the long term because as soon as you start to eat regularly again your body will gain the weight back. Unless you have the willpower to sustain ~1100 calories for the rest of your life . . . and in that case, you or they have way more willpower than I do.
  • stevencloser
    stevencloser Posts: 8,911 Member
    Here is an interesting article that answers your question as to why eating a VLCD is a bad idea. You are not giving your body the fuel it needs to function properly.

    http://www.bodyrecomposition.com/research-review/dissecting-the-energy-needs-of-the-body-research-review.html


    As you can see in the chart organs needs a minimum to function properly, in the "average" human the following figures are used:

    Liver 200
    Brain 240
    Heart 400
    Kidneys 400

    As you can see in just these 4 organs the average person needs to consume 1240 calories a day to allow normal organ function. Its up to you whether or not to believe it, or even care; this was just to answer your questions.

    TL;DR - Because its not necessary and can be dangerous.
    But does it say anywhere in there that your body needs those 1240 calories from TODAY's food? I think it's understood that bodies use stored fat calories to fuel deficits.

    Even Lyle has a very low calorie diet plan. It goes down to below 800 calories, I believe.

    No it doesn't but if you are eating under 1200 calories a day for an extended period of time where do you expect to get the fuel from? I didn't write the article but I understand that eating a VLCD is a bad idea.... and who is Lyle?
    Lyle McDonald, the author of that blog you linked to.

    You get the fuel from the fat you're trying to burn off in the first place. People without excess body fat to lose of course should not do VLCD.

    The point of that article has nothing to do with VLCD. It's "the idea that skeletal muscle burns massive numbers of calories would appear to be 100% incorrect." Which is another big MFP myth: "Build muscle to increase your RMR!"
    Depends on what you understand under "massive". Two people of average height at the same (about average) weight (specifically 5'10'' and 165 is what I took) , one with 20% bf and one with 10% bf, the one with 10% bf will have a higher RMR by about 160 calories, which is 10% more.
  • WalkingAlong
    WalkingAlong Posts: 4,926 Member
    I didn't make the connection with the Lyle reference, I cant comment on his eating habits. Again, what I do know is eating less calories than your body needs to function is a bad idea.


    Also I understand the point of that article has nothing to do with VLCD i was trying to be HELPFUL and demonstrate what calories your body needs to function.

    Why are you trying to troll?
    Why is my opinion a troll? We're all trying to be helpful. A discussion where only one viewpoint is presented isn't very helpful.

    Eating less than your body needs is how weight loss occurs, so it's not a bad idea for overweight people.
  • Mischievous_Rascal
    Mischievous_Rascal Posts: 1,791 Member
    Here is an interesting article that answers your question as to why eating a VLCD is a bad idea. You are not giving your body the fuel it needs to function properly.

    http://www.bodyrecomposition.com/research-review/dissecting-the-energy-needs-of-the-body-research-review.html


    As you can see in the chart organs needs a minimum to function properly, in the "average" human the following figures are used:

    Liver 200
    Brain 240
    Heart 400
    Kidneys 400

    As you can see in just these 4 organs the average person needs to consume 1240 calories a day to allow normal organ function. Its up to you whether or not to believe it, or even care; this was just to answer your questions.

    TL;DR - Because its not necessary and can be dangerous.
    But does it say anywhere in there that your body needs those 1240 calories from TODAY's food? I think it's understood that bodies use stored fat calories to fuel deficits.

    Even Lyle has a very low calorie diet plan. It goes down to below 800 calories, I believe.

    But your body will burn muscle over fat, first, just because it's easier to convert to energy. You would have to agree that preserving muscle mass should be a priority as you lose weight, yes? You need to exercise and get adequate protein for this to happen. So you need to eat above your basic bodily function to account for exercise, and getting enough protein on 1200 is really difficult.
  • FeebRyan
    FeebRyan Posts: 738 Member
    What amazes me is the amount of people who say that doctors will give you 1200 calories a day to survive if you are unable to feed yourself.

    This is completely untrue, I have a peg feeding certificate and regardless of shape or size, everyone gets the same 1000 calorie peg feed over a 24 hours period.
  • SugaryLynx
    SugaryLynx Posts: 2,640 Member
    Eating less than your body needs is how weight loss occurs, so it's not a bad idea for overweight people.

    Right. But eating far too little is how muscle loss can occur along with fat loss. That's not ideal loss and why people tend to recommend above 1200 to lose unless morbidly obese and facing death or very short. Those with much more fat to lose might be able to temporarily take in 1200(Non net) or less without much muscle loss but it certainly isn't necessary. Those that do should be monitored by a doctor too, not a bunch of Internet strangers.

    Plus, I'd rather eat more than less, increase my odds of retaining muscle during a cut, than race to finish and end up potentially metabolically damaged at a VLCD or losing all my muscle and ending up "skinny fat". Another huge concern is vital organs, hair, nails.

    I mean, even if there is a chance no negative effects were to come of it, worth the gamble? Nah.
  • pyrowill
    pyrowill Posts: 1,163 Member
    The fact that you are only really using very obese people/bariatric patients as an example speaks for itself. No one said VLC diets are a terrible idea for those types of people. But they are probably in the extreme minority. It would be a good idea to not start your argument generalising, and then changing your mind and focusing it on a specific group of people.
  • WalkingAlong
    WalkingAlong Posts: 4,926 Member
    But your body will burn muscle over fat, first, just because it's easier to convert to energy.
    Do you have anything that supports that assertion? Fat is the easiest dietary macronutrient to convert to energy, using only 2-3% of its calories. Protein is around 30%. Fat is much easier to convert to energy.

    What evolutionary sense would it make for the body to store excess calories as fat if it then accessed muscle in times of famine?
  • cwolfman13
    cwolfman13 Posts: 41,865 Member
    Anorexic...there are **** tons of these pro-anorexic threads on MFP...tons.
    Well this isn't one of them. I am talking about obesity management.

    Just wait...they'll be along shortly...the anorexics I mean....glorifying their 500 calorie per day diets and how they just never feel hungry...and just want to be a size zero, and how awesome it is to weight 98 Lbs, etc.

    Maybe hang out here a little while and see where these kind of threads generally go and maybe you'll see why so many of us are generally speak out against this. You're new here, and haven't witnessed the fall out that often occurs.

    By the by, there's a tremendous difference between having surgery and/or otherwise being obese and being on a SUPERVISED VLCD and just willy nilly coming to MFP without any knowledge of actual nutrition and doing the same....huge difference.
  • bcattoes
    bcattoes Posts: 17,299 Member
    Other than the health implications of non Clinician monitored VLC diets as mentioned above. The majority of people that do them are likely to gain the weight plus more back. Also there is a thing why make yourself miserable while losing weight that's why most people fail. If you hate doing something you are not going to keep at it.

    I'm not sure statistics would back up these statements. I don't know about VLCD in general, but the latest statistics I've seen is that those would lose weight via surgery tend to keep the weight off longer than those who lose by diet and exercise without surgery.
  • msf74
    msf74 Posts: 3,498 Member
    Because extreme restrictions usually result in extreme reactions (the most common being bingeing / yo yo dieting.)

    The most problematic part of VLCD dieting isn't physiological (generally) in my view.

    It's what it does to your mind - an unusual pre-occupation or obsession with food, low mood, anxiety, anger, irritability, (and if you read what happened to the healthy, well adjusted chaps who took part in the Minnesota Semi Starvation experiment - self harm.)

    Low cal dieting has a propensity for harm which outweighs the benefits, unless it is done in a well structured manner.
  • EvgeniZyntx
    EvgeniZyntx Posts: 24,208 Member
    Anorexic...there are **** tons of these pro-anorexic threads on MFP...tons.

    Well this isn't one of them. I am talking about obesity management.
    Here is an interesting article that answers your question as to why eating a VLCD is a bad idea. You are not giving your body the fuel it needs to function properly.

    Based on that, bariatric surgery is a bad idea. Yet some people benefit from bariatric surgery.

    Different approaches to weight loss may work for different people. One obese person may need to see more rapid initial weight loss in order to get into stride and start feeling better about exercise, etc. For another person, slow and steady may be the best approach.

    But there are no high quality scientific data to support this notion that slow weight loss is the best approach for everyone.

    It's all about medical cost benefit and risks.

    Bariatric surgery, like all surgery is a "bad" idea in that it will result in a number of deaths each year (1% to 3%...are the US numbers). However, sometimes it makes sense.

    There is strong medical information and scientific evidence that certain risks are increased with rapid weight loss - these may be balanced out by other risks of living with obesity - so while slow weight loss isn't the best approach for everyone, it is the reference approach to discuss on a board without clinical support - if you want to try VLCDs, use medical supervision, and this is not the place to promote them.
  • venus_blue
    venus_blue Posts: 103 Member
    There's this myth mainly seems to be promoted by the diet industry that losing weight is incredibly hard for everyone and you have to deprive yourself, suffer and buy into one of their products to do this. When in reality its a lot easier than most people think it just takes, consistency, some patience, common sense and the will to do it and you really don't have to be miserable.

    This is such a true and powerful statement. I struggled with weight loss and used to think if I wasn't hungry and miserable, I couldn't possibly lose enough weight. I gained and lost the same 40-50 pounds for about ten years eating VLC. A couple of years ago I realized it didn't have to be a struggle. My will has wavered, and I've let myself down from time to time, but not because it was too hard. Frankly, it was mostly a lack of patience and consistency.
  • WalkingAlong
    WalkingAlong Posts: 4,926 Member
    Depends on what you understand under "massive". Two people of average height at the same (about average) weight (specifically 5'10'' and 165 is what I took) , one with 20% bf and one with 10% bf, the one with 10% bf will have a higher RMR by about 160 calories, which is 10% more.
    I keep seeing that now they're saying it's more like 6 calorie per pound per day, so the extra 10% LBM there would be around 16*6=96 calories a day. Going from 20% BF to 10% is a huge change.
  • WalkingAlong
    WalkingAlong Posts: 4,926 Member
    Eating less than your body needs is how weight loss occurs, so it's not a bad idea for overweight people.

    Right. But eating far too little is how muscle loss can occur along with fat loss.
    Muscle loss always occurs along with fat loss, and it should occur because someone obese doesn't need as much muscle at a healthy weight. A lot of the body matter decreases... organs shrink, blood volume shrinks, water volume shrinks.

    I haven't really seen a lot of support for 'lower deficits mean more preserved LBM'. I've asked and people show me a couple studies from the 80s. The current research seems to show more support for the opposite-- that VLCD leads to greater weight loss maintained over the long term.

    I'm not advocating VLCD, I just think the fear of it here is overblown. I imagine for every anorexic teen reading here there are many WLS patients eating fine at VLCD, saying nothing here.
  • _Resolve_
    _Resolve_ Posts: 735 Member
    I didn't make the connection with the Lyle reference, I cant comment on his eating habits. Again, what I do know is eating less calories than your body needs to function is a bad idea.


    Also I understand the point of that article has nothing to do with VLCD i was trying to be HELPFUL and demonstrate what calories your body needs to function.

    Why are you trying to troll?
    Why is my opinion a troll? We're all trying to be helpful. A discussion where only one viewpoint is presented isn't very helpful.

    Eating less than your body needs is how weight loss occurs, so it's not a bad idea for overweight people.

    I pretty sure I understand how weight loss occurs.
  • WalkingAlong
    WalkingAlong Posts: 4,926 Member
    Right, you know you burned fat calories to fuel your activities. Do you believe your body fueled your BMR from today's food and fueled the rest of your activities from stored fat?
  • alexis831
    alexis831 Posts: 469 Member
    I locked by diary for this very reason. I am almost at my pre-c-section#3 body however, I am barely 5’1 and about 108lbs and 19% body fat. If I didn’t work out at my sitting job I only burn 1450-1550 calories a day meaning a 1200 calorie diet with a -250 to -350 deficit would take forever to get there. I usually take in around 1k calories a day (-500/-600 deficit) give or take as I fight off that last little bit of my stubborn lower belly to earn my 8pk back again. Every time I pump out a kid and have my diet open I get crap from everyone saying, I can’t possibly be healthy eating under 1200 calories. No one takes into account height, weight with current calorical burns in a day they just see someone eating under 1200 and go crazy on them. Kinda got tired of it and stopped coming to these forums because I was tired of arguing with stupid.
  • FIT_Goat
    FIT_Goat Posts: 4,224 Member
    Even Lyle has a very low calorie diet plan. It goes down to below 800 calories, I believe.

    Have you read his book on crash dieting? That is the one where he discusses that plan. He stresses that it is rarely appropriate (and when it might be), should never be long term, and he discusses tons of things you need to mind in order to avoid harming yourself. Even with that, he points out that you are harming your metabolism and will likely suffer negative effects.

    To reduce those damages, his plan has structured refeeds, full diet breaks (where you eat at maintenance for a few weeks), and other periods of high calories. It is hardly a good example of VLC dieting endorsement. Even if you were to mind all of the details and specifics he goes into (which is hard), he recommends not doing that diet and instead following a different and more sustainable diet (he recommends his own books on those diets).

    Edit: He only published that guide because he recognizes that there are idiots who will do VLC diets regardless of how bad they are and he wanted to reduce the damage they were going to do to themselves to the bare minimum. He doesn't endorse such plans.
  • neandermagnon
    neandermagnon Posts: 7,436 Member
    Here is an interesting article that answers your question as to why eating a VLCD is a bad idea. You are not giving your body the fuel it needs to function properly.

    http://www.bodyrecomposition.com/research-review/dissecting-the-energy-needs-of-the-body-research-review.html


    As you can see in the chart organs needs a minimum to function properly, in the "average" human the following figures are used:

    Liver 200
    Brain 240
    Heart 400
    Kidneys 400

    As you can see in just these 4 organs the average person needs to consume 1240 calories a day to allow normal organ function. Its up to you whether or not to believe it, or even care; this was just to answer your questions.

    TL;DR - Because its not necessary and can be dangerous.

    I actually wonder about this when I read it. Why isn't my body, a survival beast, at least in evolutionary terms, happily gobbling down my excess fat every day to provide the calories my vital organs need regardless of how much I eat that day?

    because fat is what's going to make you survive a food shortage - your body wants to make your fat last as long as possible. This is why your body will catabolise skeletal muscle to make fat last longer in a food shortage. Also, your BMR is reduced by more than what you'd expect from the catabolism of lean mass alone (this is called adaptive thermogenesis) because it's diverting energy away from non-essential purposes (such as your reproductive system, brain, skin, nails and hair) to make your fat stores last even longer. These changes increase your chances of surviving a food shortage but it's at a cost to general health and wellbeing - less energy going to non-essential functions makes you more prone to being ill, it makes you look ill, it makes you feel tired and run down, and the loss of lean body mass (especially if it's combined with a cessation in menstruation (for women) or falling sperm count (for men)) increases the risk of osteoporosis, and loss of muscle tissue and bone density makes the whole body weaker.

    The above won't happen straight away in a food shortage (aggressive calorie deficit) - but there are several behavioural responses that kick in pretty early on, that evolved to stop people or animals from accidentally starving to death, such as increased hunger and binge eating... so many people who do aggressive calorie deficits succumb to binge eating, then blame themselves for their lack of willpower and often get stuck in a cycle of excessive restriction and binge eating... this results in the body composition worsening (loss of lean mass in the restriction phase and fat storage post-binge)... for a Homo erectus enduring a food shortage this is good news as the fat ensures they'll survive longer and the loss of lean mass makes their whole body able to run on fewer calories....... but for a Homo sapiens who's trying to diet down to get a flat stomach and look lean and toned, it's very bad news. It means they'll maintain their body weight at a lower calorie intake and will be hungry and miserable and beating themselves up over binge eating, and their body fat will increase as a result of binge eating.

    So basically, the human body is actually extremely good at surviving on too little food... but the changes in the body that enable it to do this result in sub-optimal health and worsening of body composition, and also make people freaking miserable. I'm sure Homo erectus people were extremely miserable while enduring food shortages... but for most Homo sapiens people nowadays it's self-induced..... and it's not at all necessary to succeed at fat loss.

    A conservative calorie deficit is best, in order to avoid all the above problems (especially the excessive hunger and binge eating which kicks in long before any physical health issues happen), plus strength training and adequate protein intake, in order to protect the lean mass and only lose fat. in evolutionary terms, this is emulating what life would have been like during the harsher seasons in the year, when people got nearly enough to eat but not quite, but had to carry on hunting and gathering... in fact the cutting and bulking cycles of bodybuilders and strength athletes mimic this the best, i.e. cutting cycles = the harsher seasons of the year, fat is lost but muscle is maintained in order to keep on hunting successfully (because the muscles are being used, they're protected to some extent from catabolism, but it needs to be fairly strenuous exercise, because unused muscle fibres are likely to be catabolised).... bulking cycles = more plentiful time of the year where you still need to keep on hunting, but the more plentiful food means your muscles can grow a little bigger and you can lay down a little fat that's going to see you through the harsher times of the year.
  • QuietBloom
    QuietBloom Posts: 5,413 Member
    1200 calories is not considered VLC.
  • bcattoes
    bcattoes Posts: 17,299 Member
    1200 calories is not considered VLC.

    You must be talking about the real world, the world outside MFP.
  • _Resolve_
    _Resolve_ Posts: 735 Member
    Right, you know you burned fat calories to fuel your activities. Do you believe your body fueled your BMR from today's food and fueled the rest of your activities from stored fat?

    I think you are painting with a pretty broad brush on what fuels what. Depending on what zone i keep my heart rate in I can better judge what I am burning. For example when I am cycling if I keep my heart rate 50%-60% I will burn off the glucose stores in my body (that is how I maintain my type two without medication), 60%-70% I will enter into fat burning, 70-Vo2 Max will use carbs as a primary fuel source. So no I don't agree with you that fat fuels the majority of my activities unless I want it to, and If I do I will keep my heart rate within the 50-60% vo2 max range while I do whatever it is I am doing that day.
  • ironanimal
    ironanimal Posts: 5,922 Member
    Here is an interesting article that answers your question as to why eating a VLCD is a bad idea. You are not giving your body the fuel it needs to function properly.

    http://www.bodyrecomposition.com/research-review/dissecting-the-energy-needs-of-the-body-research-review.html


    As you can see in the chart organs needs a minimum to function properly, in the "average" human the following figures are used:

    Liver 200
    Brain 240
    Heart 400
    Kidneys 400

    As you can see in just these 4 organs the average person needs to consume 1240 calories a day to allow normal organ function. Its up to you whether or not to believe it, or even care; this was just to answer your questions.

    TL;DR - Because its not necessary and can be dangerous.

    I actually wonder about this when I read it. Why isn't my body, a survival beast, at least in evolutionary terms, happily gobbling down my excess fat every day to provide the calories my vital organs need regardless of how much I eat that day?
    Because fat metabolism only happens so quickly. If you exceed your body's ability to metabolise fat, the deficit has to be taken from other sources of energy; muscle, bone, connective tissues etc.

    I'm not sure of the actual maximal rate of fat metabolism, and haven't found any literature on the numbers, though.
  • perseverance14
    perseverance14 Posts: 1,364 Member
    The problem is, there are way too many who are not in the obese category doing these. If you do one, as soon as you are out of the obese category you should eat more, it is bad for you to do that long term, plus doing in obese range doesn't cost you as much muscle, it does after that. I think there is nothing wrong with telling somebody when they are in danger of harming their body. It is not just strength (which is very important) you lose from losing muscle, you also lower your metabolism by losing lean tissue, and at that rate if you ever eat more than low calories you could easily gain because your metabolism has adapted to low calorie eating. Eating lower calories IMHO should be what you do for a time, but as you can eat more you should, especially as soon as you are out of obese range, then you should eat as much as you can and still lose a safe amount, which once you are out of obese range may be 2 lbs. per week at first, but it is not long until it is 1 lb, then 0.5 lb., and if you lose more than that you risk losing muscle.
  • Meerataila
    Meerataila Posts: 1,885 Member
    Here is an interesting article that answers your question as to why eating a VLCD is a bad idea. You are not giving your body the fuel it needs to function properly.

    http://www.bodyrecomposition.com/research-review/dissecting-the-energy-needs-of-the-body-research-review.html


    As you can see in the chart organs needs a minimum to function properly, in the "average" human the following figures are used:

    Liver 200
    Brain 240
    Heart 400
    Kidneys 400

    As you can see in just these 4 organs the average person needs to consume 1240 calories a day to allow normal organ function. Its up to you whether or not to believe it, or even care; this was just to answer your questions.

    TL;DR - Because its not necessary and can be dangerous.

    I actually wonder about this when I read it. Why isn't my body, a survival beast, at least in evolutionary terms, happily gobbling down my excess fat every day to provide the calories my vital organs need regardless of how much I eat that day?
    Because fat metabolism only happens so quickly. If you exceed your body's ability to metabolise fat, the deficit has to be taken from other sources of energy; muscle, bone, connective tissues etc.

    I'm not sure of the actual maximal rate of fat metabolism, and haven't found any literature on the numbers, though.

    That makes sense. Thanks!
  • perseverance14
    perseverance14 Posts: 1,364 Member
    1200 calories is not considered VLC.
    Low calorie is 800-1200, very low calorie is 800 or less.
  • FIT_Goat
    FIT_Goat Posts: 4,224 Member
    Because fat metabolism only happens so quickly. If you exceed your body's ability to metabolise fat, the deficit has to be taken from other sources of energy; muscle, bone, connective tissues etc.

    I'm not sure of the actual maximal rate of fat metabolism, and haven't found any literature on the numbers, though.

    The quoted numbers typically range from 22 Cal - 32 Cal per pound of body fat per day.

    So, if you weigh 200 pounds and have 55 pounds of fat, your max deficit would be between 1,210 and 1,815 calories a day. There are studies on this, but there is also some debate about whether or not this would apply to people getting sufficient protein (the criticisms generally are around the fact that the studies use typical levels of protein and not high protein).