Tuesday, January 22, 2013

Weight-loss is NOT necessarily healthy

A new scientific report on nearly 3 million people found that people with BMI's in the "overweight" category had less risk of dying than people of normal weight.  Furthermore, while obese people had a greater mortality risk overall, those with the lowest obesity level BMI (30 to 34.9) were not more likely to die than normal-weight people.

The report, although not the first to suggest this relationship between BMI and mortality, has caught the eye of the medical community and journalists, breaking through the virtually impenetrable resistance of the heretofore fat-obsessed (bias against fat) media culture.  

The report, Association of All-Cause Mortality With Overweight and Obesity Using Standard Body Mass Index Categories, was published in the Jan. 2, 2013 edition of the prestigious Journal of the American Medical Association.  The researchers published their results of a large and carefully done meta-analysis of nearly 100 studies.

Finally, someone has said it, and others have agreed to hear it (thanks to JAMA) and get it out into the public discourse to investigate it further.  This is NOT new information--I have been teaching that fat has never been proven to cause disease, and that fitness matters more than fatness for years in the N.E.W. LIFE program, though participants and dietitians alike have been skeptical and slow to convince.  Pick up Glenn Gaesser's excellent book on this topic Big Fat Lies, an even more convincing review of the overwhelming evidence that body fat, although often associated with lifestyle disease risk factors, cannot be implicated as causative in lifestyle diseases, no matter how much the medical profession and media have tried to blame fat.  In his book Dr. Gaesser retraces the information and faulty "conclusions" in all of the studies that we have been trained on as Registered Dietitians--an attentive read will raise the hairs on the back of a dietitian's neck.  Dr. Gaesser has been saying it for years, I have been saying it for years, and finally others have picked up the ball and are beginning to toss it around. Kudos to researchers Katherine M. Flegal, PhD; Brian K. Kit, MD; Heather Orpana, PhD; Barry I. Graubard, PhD, and JAMA.

What the newly released report (and the media's review of it) does not elaborate on (yet) is what I see as a the bigger two-fold problem:

1)  To the extent that health professionals of all types have led the public thinking that they must lose weight in order to reduce their risk of lifestyle disease, we leave them barking up the wrong tree.  Given how entrenched this thinking is, I wonder how much it is going to take to undo the trend.  It will mean honestly admitting where many strong and wrong recommendations have been given.  Already I have heard the skeptical minimization of this "one" report by a prestigious medical professional interviewed by the media. 

2)  An overwhelming amount (underlined for emphasis below) of evidence shows that weight-loss can actually be harmful, sometimes very harmful.  Consider the following, summarized from Gaesser's excellent book Big Fat Lies (the rest of this blog is longer than the normal quick summary support, but that is precisely the point--the overwhelming amount of convincing evidence that people are not being made aware of):
  • Fifteen studies published between 1983-1993 show that weight loss increases the risk of premature death by up to 260%.
  • Dieters, especially yo-yo dieters (who make up about 90% of the dieters in this country), have a risk for Type II diabetes and for cardiovascular disease that is up to twice that of "overweight" people who remain fat.
  • Weight loss was associated with 40-260% higher death rate when researchers devised 36 different ways of comparing causes of death and amount of body weight lost in a follow-up of the NHANES I study (1971-74) in 2,453 men and 2,739 women.
  • In 20 of 29 groups weight loss increased the death rate from heart disease and stroke from 7-167% in 800,000 men and women tracked by the American Cancer Society.
  • In 1995 the Centers for Disease Control and the American Cancer Society reexamined some of the data from the earlier ACS study focusing specifically on 43,457 women who had never smoked and who were overweight when the study began.  For the 2/3 of the women who were healthy to begin with who intentionally lost between 1-19 pounds, premature death rate from all causes was increased 40-70%. Unintentional weight gain, on the other hand, had no adverse effects on premature death.
  • In a study of 12,000 men at high risk for heart disease men who lost weight actually had a greater risk of dying during the nearly 4 years of follow-up.
  • In the Harvard Alumni study a subgroup of 11,700 men who had a weight loss of more than 11 pounds during 1962-1977 had a 75% greater risk of dying from heart disease by 1988.
  • Dr. Steven Blair and his colleagues studied 10,500 men at high risk for heart disease enrolled in the Multiple Risk Factor Intervention Trial in 1973 and found that weight loss, even for a subgroup of men who would seem to be optimum beneficiaries of weight loss, resulted in 61-242% higher mortality rate from cardiovascular disease.  Weight gain did not significantly increase mortality from heart disease.
  • A study involving 200 extremely heavy young men on a weight loss program at the Veterans Administration Wadsworth Medical Center in Los Angeles between 1960-1975 fasted, lost 60-90 pounds, and were followed for the next 7+ years.  Almost all of the men gained everything back and more (surprise).  It was only after the radical weight loss that the men started to have health problems--75 developed diabetes, 39 became hypertensive, 19 were diagnosed with cardiovascular disease, and 27 went undiagnosed and died of cardiovascular disease.
  • A study at Harvard Medical School involved 12 young men and women (small study) who agreed to follow Dr. Stillman's low-carbohyddrate plan in The Doctor's Quick Weight Loss Diet.  Although average weight dropped by 7 pounds during the 3-17 days on the diet, the subjects' total cholesterol rose from an average of 215 mg/dl to 248, which put them in the high risk category for heart disease.  Five million copies of the book have been sold.
  • A study involving 24 obese men and women (again, a small study) who followed the diet plan recommended by Dr. Atkins' Diet Revolution found that after 8 weeks on the diet the group's LDL cholesterol increased by an average of 19%.  The 10 women in the study had lost an average of 15 pounds but their LDL cholesterol shot up by 33%, and their HDL cholesterol decreased by 10%.  This book sold 20 million copies.
Dr. Gaesser notes that atherosclerosis is a disease characterized not by a slow, steady narrowing of the blood vessels over time but by sudden spurts in the growth of the fat-and-cholesterol-loaded deposits that clog arteries.  Just a couple weeks of high-cholesterol counts resulting from these diets could do more harm than several years of the slightly higher-than-normal cholesterol of the individuals before the diets.

Note:  The amount of weight loss associated with the higher mortality rates reported in these studies was, in most cases, between about 10-30 pounds, amounts very similar to what dieters lose or would like to lose, and what health professionals frequently recommend! 

Finally, any diet, regardless of its composition, can provoke the artery-clogging process because dieting frequently leads to bingeing, particularly on foods that are not heart-healthy.  Dieting intensifies preferences for high-fat and sugar-laden foods.  Other consequences of dieting include increased risk for osteoporosis, abnormally low levels of female reproductive hormones, and an epidemic of eating disorders.

and in animals . . .

·   Veterinary scientists at University of Illinois put pigs on yo-yo diets (1 1/4-2 1/2 years, 4-8 diets) and found that after just a few episodes of dieting the pigs developed high blood pressure.  By the end of the study investigators detected severe damage to the heart muscle and coronary blood vessels of most of the pigs.

·   Researchers at University of Mississippi School of Medicine put lab mice on a onetime low-calorie diet.  As soon as the mice were allowed to resume normal, unrestricted eating, their systolic blood pressures more than doubled within a week.  Although the hypertension was transient, lasting just a couple of weeks, the damage was not--coronary artery damage was found in 80% of the mice.

Overall, the evidence we cannot and should no longer ignore is that losing weight seems to increase the chances of dying from a disease for which weight loss is frequently prescribed to help cure!  Strong evidence indicates this paradox: weight loss is seemingly therapeutic in its effect on many of the risk factors for cardiovascular disease, and dangerous in its association with increased mortality.  It has become increasingly evident that we have not fully understood the "risk factors" implicated as targets to focus on.  For example, we now know that cardiovascular disease is a multifactorial disease, although all everyone heard for decades was that LDL "bad cholesterol" was to blame.

Furthermore, the likely explanation of the paradox lies in the fact that weight loss (especially by dieting) begets weight gain.  For example,
  • In the Harvard study those who had a net loss of more than 11 pounds between 1962-1977 had a cumulative weight loss of 99 pounds, which means they had also gained a considerable amount of weight over the years. Men who had lost and gained the most total pounds had an 80% higher rate of heart disease and a 123% higher rate of Type II diabetes.  Those alumni who had dieted frequently had nearly double the risk for Type II diabetes, hypertension, and coronary heart disease compared with those who never dieted.
  • In the Framingham Heart Study, after more than 3 decades of follow-up evaluations, subjects whose body weights yo-yoed the most had up to 100% greater risk of death from heart disease.
  • Higher rates of heart disease in those who yo-yoed the most were also found in the Multiple Risk Factor Intervention Trial.
  • Dr. Ancel Keys and his colleagues at University of Minnesota found that during the weight-regaining phase of the Minnesota Experiments in which 32 men were put on a 24-week diet with about half the calories they were accustomed to, many of the men seemed to be on the verge of congestive heart failure, with one man hospitalized with severe cardiovascular problems.
  • The experience of the population of Leningrad, after being unintentionally put on a semi-starvation diet for 5 months, not surprisingly fits with current recommendations--people lost weight and hypertension was reduced.  However, after the siege was lifted and food became plentiful, 10,000 people were examined and it was found that the incidence of high blood pressure had shot up by 100-400%, with a similar increase in the incidence of hypertension-related vascular damage at autopsy.
  • Even the government itself issued a report on “Obesity and Health” by the Department of Health, Education and Welfare in 1966 in which 9 experts in health and nutrition warned the public that “the frequent weight gains and losses indulged in by many obese patients . . . may be actually more harmful than maintenance of a steady weight at a high level”.
So while we may not fully understand why body weight and body fat do not necessarily correlate with mortality as has been purported unceasingly for the last several decades, we can say that the evidence most assuredly does implicate yo-yo dieting is dangerous. Even the skeptics of this "new" information, who want to continue to blame fat for disease, can at least agree that everyone ought to take dieting less flippantly and only focus on weight-loss when assured that the weight-loss is the result of focusing on a healthy lifestyle, and  that it will be once and for all without any repetitive yo-yo diets to follow.

So this "new" evidence reported in JAMA is yet one more study supporting Glenn Gaesser's contention that body fat should not take all the blame for causing disease.  I hope it doesn't take another 45 years to seriously consider the fact that convincing and overwhelming evidence also shows that in the effort to produce weight-loss, individuals actually increase their risk for earlier mortality.  

I have said it for 20 years, and I'll say it again, it is an uncompromisable principle of the N.E.W. LIFE program that N.E.W. LIFE Dietitians encourage N.E.W. LIFE participants in every way possible to take the obsessive focus off of weight and focus on lifestyle behaviors instead.  If the weight is supposed to come off, it will.  The message that body fat is not to blame has not been a popular one, but one that must be clearly presented if we are to assist people to change the true causes of lifestyle disease, which is not weight per-se, but excess animal and processed (trans) fat in the diet and lack of exercise.  

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