I continually read a great many books, articles, blogs, and forum posts on the subject of obesity.

No one,…. not even the most qualified medical doctor or scientist, … knows everything or holds only beliefs that are absolutely correct.

However, I am often amazed by the vast amount of existing misconceptions, myths, and wishful-thinking that gets spread and promoted by people who present themselves as obesity “experts” or “gurus”.

One thing that Scientists know for sure about obesity management, is the sad fact, that no diet, exercise, medication, not even bariatric surgery, will permanently reset the body’s tendency to defend and regain its body weight to its set point .... this generally being the highest weight that has been achieved and maintained for a notable length of time.



Thus, any effective long-term treatment MUST OFFSET the complex neurobiology which is designed to eventually doom every weight-loss attempt to ultimately "fail".

A comprehensive review recently published in Endocrine Reviews describes the complexity of  the biological system that regulates our body weight.

The 30+ page research paper, backed by about 350 scientific citations, was written by the undisputed leaders in the medical field of Endocrinology (Michael Schwartz, Randy Seeley, Eric Ravussin, Rudolph Leibel and colleagues)  and is actually a “Scientific Statement” from the Endocrine Society. 

In other words, these Scientists know that they are talking about when they speak about the Science of Energy Balance, and in this paper they outline in excruciating scientific detail just how complex the biological system that regulates, defends, and restores body weight actually is.

From the Abstract of this research paper:

We included evidence from basic science, clinical, and epidemiological literature to assess current knowledge regarding mechanisms underlying excess body-fat accumulation, the biological defense of excess fat mass, and the tendency for lost weight to be regained.

A major area of emphasis is the science of energy homeostasis, the biological process that maintains weight stability by actively matching energy intake to energy expenditure over time.

Growing evidence suggests that obesity is a disorder of the energy homeostasis system, rather than simply arising from the passive accumulation of excess weight.

Their position is that, despite all we have learned about this system, we are still far from fully understanding it.

Science knows about one of the pathways, but there are many pathways in a complex network of multiple interacting pathways that involve virtually every part of the brain.

They say that the medical field currently needs a great deal more information about the specifics of this issue:

The identification of neuromolecular mechanisms that integrate short-term and long-term control of feeding behavior, such that calorie intake precisely matches energy expenditure over long time intervals, will almost certainly enable better preventive and therapeutic approaches to obesity.”

To be viable, theories of obesity pathogenesis must account not only for how excess body fat is acquired, but also for how excess body fat comes to be biologically defended.

Answering this question requires an improved understanding of the neuro-molecular elements that underlie a “defended” level of body fat. What are the molecular/neuroanatomic predicates that help establish and defend a “set point” for adiposity? How do these elements regulate feeding behavior and/or energy expenditure, so as to achieve long-term energy balance? By what mechanisms is an apparently higher set point established and defended in individuals who are obese?”

They conclude that:

Given that recovery of lost weight ... (the normal, physiological response to weight loss irrespective of one’s starting weight) ... is the largest single obstacle to effective long-term weight loss, we cannot overstate the importance of a coherent understanding of obesity-associated alterations of the energy homeostasis system.”

So, in essence, this scientific paper shows why no simple solution to obesity is in sight; details the existence of an enormous Problem; and raises Questions for which Science still needs to find answers.

To get a simple explanation of the basic concept, see: Set Point. 

Any “health & wellness” professional, medical doctor, or guru who claims that any particular Diet, Behavior, or LifeStyle can fundamentally change the part of the body’s biology which acts to protect and restore body fat in the long term is Simply Wrong. 

They are either spreading a Lie, sharing a Myth, or offering a hypothesis for which no proof or reasonable evidence exists… which means that they are simply sharing their own Wishful-Thinking.

At this point, all credible Scientific Research indicates the following:

No matter how much weight gets lost, or is maintained for the short-term, …
No matter whether that weight loss was slow or fast, ...
No matter when food intake occurs ...
No matter whether “unprocessed” or “healthy” food is eaten, ...

Ultimately NO diet or behavior
manages to “reset” the body-weight set point to a lower level,
in order to biologically “stabilize” weight loss for the long-term.

NOTE: Originally posted on 7/23/2017.  Bumped up for new viewers.

The Statement:

"You could
stand to lose a few pounds."

A Proper Response:

"Thank you for sharing
your meaningless value judgment."

Are BMI and BMR
interchangeable terms?

In a recent conversation with an M.D., when giving an opinion he incorrectly used the term BMI instead of BMR. I interjected “BMR?”, and he frowned & shook his head sideways indicating “no”. 

I continued with “BMR, not BMI,.. you know .. Basil Metabolic Rate, … from formulas like Harris-Benedict, or Mifflin? The calories burned without activity, like when you are in a coma.”  He responded on a different track, saying people used a lot of energy even in a coma, and never made any correction, or acknowledgment that he even understood his error.

So I thought, Is there some basic information about BMI & BMR that I missed? Are they, in some way, interchangeably connected?  Further research verified my original understanding, which is spelled-out below.

BMI or BMR?

First, although the abbreviations BMI and BMR sound similar, they stand for two separate things.

Your BMI, or body mass index, is a number calculated from your height and weight which is then used to assess your body composition.

Your BMR, or basal metabolic rate, is the number of calories you burn when your body is at rest. 

These two terms are independent of each other, but your BMI may indirectly affect your BMR.

Body Mass Index (BMI)

Your BMI is an indirect measure of your body composition -- or how much body fat you have. Although BMI doesn’t measure body fat directly, it uses your weight and height to determine whether you’re classified as underweight, normal weight, overweight or obese. This measurement correlates moderately well with other measurements of body fat such as skinfold measurements and underwater weighing.

BMI is based on your height & your weight.   There are many online calculators that will easily run BMI equations and provide your individual numbers.   Here’s a link to one that I commonly use.

The equation looks like this: BMI = (weight / height x height) x 703.

A BMI below 18.5 indicates that you’re underweight; a BMI between 18.5 and 24.9 classifies you as a normal weight; a BMI between 25 and 29.9 puts you in the overweight category; a BMI of 30 or above classifies you as obese.

Limitations of BMI

Because it's not a direct measurement, BMI is only used as a screening tool and is not considered a diagnostic test. There are also some limitations to this measurement.

Because BMI uses only height and weight, it doesn’t account for people who may be of below-average height but above-average muscle mass, like bodybuilders. If a man has a lot of muscle, which is denser than fat, his BMI may categorize him as overweight, when his weight is actually healthy.

BMI also doesn’t adjust for age or gender. Women naturally have more body fat than men, and older people tend to have more body fat than younger people. So a sedentary older woman with a normal-to-overweght BMI, who has low muscle mass might be mistakenly considered to be "overly" fat.

Basal Metabolic Rate

Your BMR is the number of calories your body burns at rest to do basic functions like breathing, digesting, keeping your heart beating and all the other physiological tasks that keep you alive.

Your BMR is partly determined by genetics, but other factors, like your body composition and activity level, may also have an effect on your BMR.

There are equations used to determine your BMR, and they differ based on whether you're a man or a woman.  The two most widely formulas to determine BMR are the newer and more accurate Mifflin St JEOR equation, and the old pre-1920s Harris-Benedict equation. The formulas use height, weight, and age.   

While these equations can be a good starting place, it is important to understand that these numbers are based on AVERAGES, and it is common for someone’s ACTUAL personal number to be 15% lower (or higher). There are also Outliers, who have individual numbers which can be VERY far away from the Average stated number.  There are many online calculators that will easily run these equations and provide your individual Number Average. Here’s a link to one I commonly use.

The Mifflin equation (1990) looks like this: 10 × (weight in kg) + (6.25 × height in cm) - (5 × age in years) - 161.  The Harris-Benedict equation (1918) looks like this:  655 + (4.35 x weight in pounds) + (4.7 x height in inches) – (4.7 x age in years).

How BMI and BMR are Connected

Several factors affect your basal metabolic rate -- and body fat composition is one of them. Those with more muscle mass tend to burn more calories at rest because muscle tissue requires more calories to maintain than fat tissue.

BMI and BMR are not directly related. However, if you have a high BMI because you have a high body fat percentage, your BMR might be lower than the number given. If you have a high BMI because you have a large amount of muscle mass, your BMR might be higher than the number given. Additionally, if you are very active, but overweight, your BMR might be higher than the number given.

BMI and BMR are Guidelines that allow nutrition and medical professionals to make educated determinations about your body composition and calorie burn, but every person should still be viewed individually.

At my age, I’ve realized two things.


You can’t
teach
common sense,
and
you can’t
fix
stupid.