The human body's REAL response to starvation/over exercising!
- Why and how diets damage you.
- Why diets generally "fail" in terms of sustaining weight loss over time
When we look at what actually happens in the human body in response to starvation/over exercising we can see that the weightloss mantra "eat less, excercise more, burn fat" is far too simplistic - to the point that it barely tells half the story!
In fact what happens is that in additrion to burning fat and carbohydrate energy stores, when the human body experiences dieting/ starvation/over exercising -
1 - it burns muscle tissue - reducing BMR (Basal Metabolic Rate = your "tickover" energy burn rate when you are at rest)
2 - it reduces involuntary movement
3 - it lowers body temperature
4 - it reduces investment in sex
(e.g. reduced gamete production, amenorrhea = no periods)
All of which reduce the total calories burned by the body - and crucially these effects are cumulative!
The more restrictive (i.e. the lower your calorie intake) your diet and the longer you diet the lower your metabolic rate is driven!
These effects continue after the starvation period is over!
Hence why a return to normal eating results in rapid weight regain, plus extra weight and why the ex-dieter ends up with a higher percentage body fat than before the diet!
evidence from (among others)
the Minnesota Starvation Study - results published in the legendary two-volume, Biology of Human Starvation (Minneapolis: University of Minneapolis, 1950).
"The experiment the starvation syndrome
The 40 young male participants were carefully selected among hundreds of volunteers for being especially psychologically and socially well-adjusted, good-humored, motivated, well-educated, active and healthy. They were put on calorie-restrictive diets of about 1,600 calorie/day, meant to reflect that experienced in war-torn regions, for 3 months. They dieted to lose 2.5 pounds a week to lose 25% of their natural body weight. The calories were more generous than many weight loss diets prescribe today!**
What this study was actually studying, of course, was dieting and restrictive eating our bodies cant tell the difference if theyre being semi-starved involuntarily like war victims or voluntarily. During the 3-month nutritional rehabilitation period after the diet, the men were randomly assigned to various nutritional regimens, with differing levels of calories, proteins and vitamins. The men lived at the lab and everything they ate and did was closely monitored, as was their health with a battery of tests. Daily exercise was walking about 3 miles a day.
...
Dr. Keys and colleagues painstakingly chronicled how the men did during the 6 months of dietary interventions and for up to a year afterwards. This study scientifically defined for the first time the starvation syndrome.
....
As the men lost weight, their physical endurance dropped by half, their strength about 10%, and their reflexes became sluggish with the men initially the most fit showing the greatest deterioration, according to Dr. Keys. The mens resting metabolic rates declined by 40%, their heart volume shrank about 20%, their pulses slowed and their body temperatures dropped. They complained of feeling cold, tired and hungry; having trouble concentrating; of impaired judgment and comprehension; dizzy spells; visual disturbances; ringing in their ears; tingling and numbing of their extremities; stomach aches, body aches and headaches; trouble sleeping; hair thinning; and their skin growing dry and thin. Their sexual function and testes size were reduced and they lost all interest in sex. They had every physical indication of accelerated aging."
There are also psychological changes brought about by dieting/starvation:
"But the psychological changes that were brought on by dieting, even among these robust men with only moderate calorie restrictions, were the most profound and unexpected. So much so that Dr. Keys called it semistarvation neurosis. The men became nervous, anxious, apathetic, withdrawn, impatient, self-critical with distorted body images and even feeling overweight, moody, emotional and depressed. A few even mutilated themselves, one chopping off three fingers in stress. They lost their ambition and feelings of adequacy, and their cultural and academic interests narrowed. They neglected their appearance, became loners and their social and family relationships suffered. They lost their senses of humor, love and compassion. Instead, they became obsessed with food, thinking, talking and reading about it constantly; developed weird eating rituals; began hoarding things; consumed vast amounts of coffee and tea; and chewed gum incessantly (as many as 40 packages a day). Binge eating episodes also became a problem as some of the men were unable to continue to restrict their eating in their hunger.
These experiences are familiar to those whove spent their lives dieting. In fact, many of the symptoms once thought to be primary features of anorexia nervosa are actually normal biological responses of undernutrition and restrictive eating, said David M. Garner, PhD., director of River Centre Clinic in Sylvania, Ohio, in Psychoeducational principles in the treatment of eating disorders (NY: Guilford Press, 1997). It was actually Dr. Keys research that first evidenced the role of dieting in increasing risks for eating disorders."
from:
http://junkfoodscience.blogspot.com/2008/02/how-weve-came-to-believe-that.html
more:
http://en.wikipedia.org/wiki/Minnesota_Starvation_Experiment
Other references
http://en.wikipedia.org/wiki/Famine_response
To sum up - dieting is phsyiologically and mentally damaging to the human body.
Notes:
{** perspective - this "dreadful" starvation of 1,600cals a day that caused these men so many problems is nearly THREE TIMES the calorie allowance my most recent ex-BBW ex-gf was and is eating on her then and current quest to lose weight. And this is on a "doctor prescribed" diet! This shows just how incredibly divorced from the actual science of human biology at least some of the "medical establishment" has become!}
- Why and how diets damage you.
- Why diets generally "fail" in terms of sustaining weight loss over time
When we look at what actually happens in the human body in response to starvation/over exercising we can see that the weightloss mantra "eat less, excercise more, burn fat" is far too simplistic - to the point that it barely tells half the story!
In fact what happens is that in additrion to burning fat and carbohydrate energy stores, when the human body experiences dieting/ starvation/over exercising -
1 - it burns muscle tissue - reducing BMR (Basal Metabolic Rate = your "tickover" energy burn rate when you are at rest)
2 - it reduces involuntary movement
3 - it lowers body temperature
4 - it reduces investment in sex
(e.g. reduced gamete production, amenorrhea = no periods)
All of which reduce the total calories burned by the body - and crucially these effects are cumulative!
The more restrictive (i.e. the lower your calorie intake) your diet and the longer you diet the lower your metabolic rate is driven!
These effects continue after the starvation period is over!
Hence why a return to normal eating results in rapid weight regain, plus extra weight and why the ex-dieter ends up with a higher percentage body fat than before the diet!
evidence from (among others)
the Minnesota Starvation Study - results published in the legendary two-volume, Biology of Human Starvation (Minneapolis: University of Minneapolis, 1950).
"The experiment the starvation syndrome
The 40 young male participants were carefully selected among hundreds of volunteers for being especially psychologically and socially well-adjusted, good-humored, motivated, well-educated, active and healthy. They were put on calorie-restrictive diets of about 1,600 calorie/day, meant to reflect that experienced in war-torn regions, for 3 months. They dieted to lose 2.5 pounds a week to lose 25% of their natural body weight. The calories were more generous than many weight loss diets prescribe today!**
What this study was actually studying, of course, was dieting and restrictive eating our bodies cant tell the difference if theyre being semi-starved involuntarily like war victims or voluntarily. During the 3-month nutritional rehabilitation period after the diet, the men were randomly assigned to various nutritional regimens, with differing levels of calories, proteins and vitamins. The men lived at the lab and everything they ate and did was closely monitored, as was their health with a battery of tests. Daily exercise was walking about 3 miles a day.
...
Dr. Keys and colleagues painstakingly chronicled how the men did during the 6 months of dietary interventions and for up to a year afterwards. This study scientifically defined for the first time the starvation syndrome.
....
As the men lost weight, their physical endurance dropped by half, their strength about 10%, and their reflexes became sluggish with the men initially the most fit showing the greatest deterioration, according to Dr. Keys. The mens resting metabolic rates declined by 40%, their heart volume shrank about 20%, their pulses slowed and their body temperatures dropped. They complained of feeling cold, tired and hungry; having trouble concentrating; of impaired judgment and comprehension; dizzy spells; visual disturbances; ringing in their ears; tingling and numbing of their extremities; stomach aches, body aches and headaches; trouble sleeping; hair thinning; and their skin growing dry and thin. Their sexual function and testes size were reduced and they lost all interest in sex. They had every physical indication of accelerated aging."
There are also psychological changes brought about by dieting/starvation:
"But the psychological changes that were brought on by dieting, even among these robust men with only moderate calorie restrictions, were the most profound and unexpected. So much so that Dr. Keys called it semistarvation neurosis. The men became nervous, anxious, apathetic, withdrawn, impatient, self-critical with distorted body images and even feeling overweight, moody, emotional and depressed. A few even mutilated themselves, one chopping off three fingers in stress. They lost their ambition and feelings of adequacy, and their cultural and academic interests narrowed. They neglected their appearance, became loners and their social and family relationships suffered. They lost their senses of humor, love and compassion. Instead, they became obsessed with food, thinking, talking and reading about it constantly; developed weird eating rituals; began hoarding things; consumed vast amounts of coffee and tea; and chewed gum incessantly (as many as 40 packages a day). Binge eating episodes also became a problem as some of the men were unable to continue to restrict their eating in their hunger.
These experiences are familiar to those whove spent their lives dieting. In fact, many of the symptoms once thought to be primary features of anorexia nervosa are actually normal biological responses of undernutrition and restrictive eating, said David M. Garner, PhD., director of River Centre Clinic in Sylvania, Ohio, in Psychoeducational principles in the treatment of eating disorders (NY: Guilford Press, 1997). It was actually Dr. Keys research that first evidenced the role of dieting in increasing risks for eating disorders."
from:
http://junkfoodscience.blogspot.com/2008/02/how-weve-came-to-believe-that.html
more:
http://en.wikipedia.org/wiki/Minnesota_Starvation_Experiment
Other references
http://en.wikipedia.org/wiki/Famine_response
To sum up - dieting is phsyiologically and mentally damaging to the human body.
Notes:
{** perspective - this "dreadful" starvation of 1,600cals a day that caused these men so many problems is nearly THREE TIMES the calorie allowance my most recent ex-BBW ex-gf was and is eating on her then and current quest to lose weight. And this is on a "doctor prescribed" diet! This shows just how incredibly divorced from the actual science of human biology at least some of the "medical establishment" has become!}
