Low-Carbohydrate Diets, Con: The Mythical Phoenix or Credible Science?

Embracing chaos and complexity: a quantum change for public health

Public health research and practice have been guided by a cognitive, rational paradigm where inputs produce linear, predictable changes in outputs. However, the conceptual and statistical assumptions underlying this paradigm may be flawed. In particular, this perspective does not adequately account for nonlinear and quantum influences on human behavior. We propose that health behavior change is better understood through the lens of chaos theory and complex adaptive systems. Key relevant principles include that behavior change (1) is often a quantum event; (2) can resemble a chaotic process that is sensitive to initial conditions, highly variable, and difficult to predict; and (3) occurs within a complex adaptive system with multiple components, where results are often greater than the sum of their parts.

Obesity management

Because obesity is associated with an increased risk of multiple health problems, it is important for gastroenterologists and all health care providers routinely to identify, evaluate, and treat patients for obesity in the course of daily practice. Therapy for obesity always begins with lifestyle management and may include pharmacotherapy or surgery. Setting an initial weight loss goal of 10% over 6 months is a realistic target, followed by long-term management.

A chaotic view of behavior change: a quantum leap for health promotion

BACKGROUND

The study of health behavior change, including nutrition and physical activity behaviors, has been rooted in a cognitive-rational paradigm. Change is conceptualized as a linear, deterministic process where individuals weigh pros and cons, and at the point at which the benefits outweigh the cost change occurs. Consistent with this paradigm, the associated statistical models have almost exclusively assumed a linear relationship between psychosocial predictors and behavior. Such a perspective however, fails to account for non-linear, quantum influences on human thought and action. Consider why after years of false starts and failed attempts, a person succeeds at increasing their physical activity, eating healthier or losing weight. Or, why after years of success a person relapses. This paper discusses a competing view of health behavior change that was presented at the 2006 annual ISBNPA meeting in Boston.

DISCUSSION

Rather than viewing behavior change from a linear perspective it can be viewed as a quantum event that can be understood through the lens of Chaos Theory and Complex Dynamic Systems. Key principles of Chaos Theory and Complex Dynamic Systems relevant to understanding health behavior change include: 1) Chaotic systems can be mathematically modeled but are nearly impossible to predict; 2) Chaotic systems are sensitive to initial conditions; 3) Complex Systems involve multiple component parts that interact in a nonlinear fashion; and 4) The results of Complex Systems are often greater than the sum of their parts. Accordingly, small changes in knowledge, attitude, efficacy, etc may dramatically alter motivation and behavioral outcomes. And the interaction of such variables can yield almost infinite potential patterns of motivation and behavior change. In the linear paradigm unaccounted for variance is generally relegated to the catch all "error" term, when in fact such "error" may represent the chaotic component of the process. The linear and chaotic paradigms are however, not mutually exclusive, as behavior change may include both chaotic and cognitive processes. Studies of addiction suggest that many decisions to change are quantum rather than planned events; motivation arrives as opposed to being planned. Moreover, changes made through quantum processes appear more enduring than those that involve more rational, planned processes. How such processes may apply to nutrition and physical activity behavior and related interventions merits examination.

An update on low-carbohydrate, high-protein diets

PURPOSE OF REVIEW

The use of low-carbohydrate diets in weight loss is an area of great controversy. In recent years, a significant amount of research has been conducted to evaluate the efficacy of these diets. This review aims to discuss mechanisms of action for weight loss; to assess impact on metabolic parameters including insulin sensitivity and cardiovascular risk parameters and to evaluate the data regarding safety and effectiveness for weight loss.

RECENT FINDINGS

Most studies demonstrate that subjects following low carbohydrate diets lose more weight over the first 3-6 months than subjects consuming control diets. This weight loss is not sustained, however, at 1 year. Carbohydrate controlled diets may be associated with increased insulin sensitivity and improved glycemic control. High carbohydrate, low fat diets appear to have a more favorable impact on total and LDL cholesterol, whereas low carbohydrate diets have been shown to significantly decrease triglyceride and increase HDL cholesterol levels in short-term studies.

SUMMARY

Low carbohydrate diets may be effective in helping people to lose weight. More long-term studies need to be performed, however, to better evaluate efficacy, safety, and impact on metabolic profile.