Why are so many agains low calorie and VLC dieting?

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.

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.

Not arguing with most of this at all, however, you'd think the body would decide to get rid of fat before going after vital organs if it was capable. Then again, I speak as a modern day human living in climate control. I suppose keeping some fat even at the cost of some organ damage might be beneficial for survival? I know I'm all of a sudden freezing in Winter since I dropped a lot of weight, and I used to hate the heat! Or maybe as you mention, it has to do with fat being needed for reproduction. I could see that.

It will run out of fat before metabolising vital organs. Metabolising of vital organs only happens in the extreme, advanced stages of starvation - when the person looks like a walking skeleton and has less than 1% body fat and virtually no skeletal muscle left) and is a last ditched attempt by the body to survive... and death from multiple organ failure usually follows.

But I don't think anyone said that your body would metabolise your vital organs before the fat runs out (if someone did then I missed it or misunderstood it)... the mention of how much energy the vital organs need, I understood to be in relation to the body catabolising skeletal muscle along with fat in order to provide a constant supply of energy for those vital organs while also conserving fat (i.e. burning less of it - fat burning doesn't cease, and fat storage doesn't happen in a deficit, but in a temporary surplus created by binge eating between episodes of excessive calorie restriction can cause fat gain).

Also, adaptive thermogenesis involves energy being diverted away from non-essential organs in order to keep the vital organs functioning, which is why people tend to have difficulty concentrating and why menstruation ceases - energy is being diverted away from the brain and reproductive system, to keep the heart and essential organs functioning.

Lots of good reasons listed in this thread. Just throwing my support behind "it's not necessary and can have adverse affects if not properly monitored by a healthcare professional"

Now...

Thank you!

Lots of good reasons listed in this thread. Just throwing my support behind "it's not necessary and can have adverse affects if not properly monitored by a healthcare professional"

The issue is longevity of that kind of diet vs. reducing calories in a more manageable amount over time. Research has shown over and over that people who go too extreme in calorie reduction tend to gain the weight back within a year or so. While it is also true that people can gain the weight back with more managed caloric deficits, it is far less. So if someone is arguing from the perspective that 1200 calories is hard to maintain long term, I agree. If someone says ANYTHING about starvation mode, they are just dead wrong.

Now, If someone does a 1200 cal thing to kick start things, I have no problem.

b) Profiles, groups, messages, posts, or wall comments that encourage anorexia, bulimia, or very low calorie diets of any kind will be removed, and may be grounds for account deletion. This includes positive references to ana/mia, purging, or self-starving. Our goal is to provide users with the tools to achieve their weight management goals at a steady, sustainable rate. Use of the site to promote, glamorize, or achieve dangerously low levels of eating is not permitted.

4 pages and no one has mentioned that MyFitnessPal's community guidelines are against very low calorie diets. The "Why" is right in the guidelines. I have bolded it.

b) Profiles, groups, messages, posts, or wall comments that encourage anorexia, bulimia, or very low calorie diets of any kind will be removed, and may be grounds for account deletion. This includes positive references to ana/mia, purging, or self-starving. Our goal is to provide users with the tools to achieve their weight management goals at a steady, sustainable rate. Use of the site to promote, glamorize, or achieve dangerously low levels of eating is not permitted.

Do you agree with him that 'sometimes it's necessary or beneficial? Because the outcry here is that it is never necessary or beneficial. I agree with him.

I never said anything about extended periods of time. Arguing that it's not ok for extended periods of time does not mean it's never ok for any periods of time.