Myth Buster #1:Weight Control Can Be Easily Achieved Through Lifestyle Modificatioln

From EHow Myth Busters

I was reading a recent published set of articles in the Bariatric Times (yes that is a legit title for a magazine...) and from a new initiative called the Metabolic Applied Research Strategy that published 5 myths that have direct applicability to this Blog, and I will post a few of them here and there over the coming weeks.

The first one is the most basic, and debunks the myth that lifestyle modification is alone sufficient for substantial weight loss in the obese (BMI > 30) population. It was interesting to me to find that there are many factors at work in undermining success, rather than the typical return to the previous indiscretions of poor dietary practices and lack of regular exercise.

Studies have shown that 80% of those who intend to lose weight through exercise and dietary change may initially lose at least 10% of their body weight, but more than 95% of those will regain all of their lost weight (or more) within the subsequent 2 - 5 years.

Surely there are volitional forces at work, but the regain in weight is not purely a matter of "choice". There are physiological factors at work that are intent on countering that weight loss for the long term.

It is true that body weight is a regulated by delicate balance between caloric intake and energy expenditure. Due to elaborate mechanisms, however, losing and maintaining that weight is quite difficult.

Fat mass is the primary source for both expected and unexpected (e.g. infection, illness, injury, increased physical activity) energy expenditures, and 'adequate' reserves are necessary.  The amount of stored fat is highly regulated based on genetic, developmental, and environmental influences.  Additionally, the physiology of body weight regulation is complex, with robust and redundant systems to ensure sufficient, but not excessive energy stores. Metabolic adaptation can occur, however, in the setting of overeating with resultant weight gain, as well as food restriction and weight loss.

The overall effect of these physiological mechanisms are to defend a stable body fat mass, or "set point" for energy storage.  Hence, the key to obesity is why certain individuals have such elevated set points.  Like so many other metabolic and physiologic 'set points' of the body (blood glucose, LDL, BP, Hct, etc.) they are not firmly "fixed" and reflect the integration of genetic predisposition.

Genetics, developmental history  and environmental exposure seem to contribute to an individual's set point for body fat mass, but the recent epidemic in obesity likely results from a change in the modern environment, leading to an inappropriately elevated set point.  Once that new set point is established, however, normal physiological mechanisms work to defend it.

Some environmental factors at work in our modern society:

*Alterations in the chemical and nutrient of food, that effect both intake and fat mass set point

*Lack of exercise and their resultant change in physiology of the body

*Chronic stress, personal distress, and disruption of regular circadian rhythms promoting obesity and metabolic dysfunction

And, unfortunately, the physiological mechanisms leading to the set point are so strong that even in the setting of willful contradictory actions (lifestyle modification), physiology almost always wins.

Fortunately for those that are morbidly obese, and perhaps beyond the ability to lose substantial amounts of weight due to chronic lack of success, and/or significant life-compromising co morbidites, there is Bariatric / Metabolic surgery which has been shown to induce the needed profound metabolic and physiologic effects that can lead to long-term durable weight loss.



Adapted from L Kaplan, R Seeley, J Harris. "Myth #1 Weight can be reliably controlled by voluntarily adjusting energy balance through diet and exercise."MARS initiative publication, Bariatric Times Vol 9 No 9. C5-C6.