Craig A. Johnston, PhD
Am J Lifestyle Med. 2012;6(1):18-20.
ABSTRACT AND INTRODUCTION
Abstract
Lifestyle interventions show considerable promise in improving levels of inflammation. This review discusses how these improvements in inflammation are consistent with a “small changes” approach.
Introduction
Managing inflammation has the potential to be a key component in warding off disease. This may be of particular importance given its link to type 2 diabetes, cardiovascular disease, metabolic syndrome, and obesity,[1–3] and the role it plays in the progression of these and other diseases. It has been speculated that physical inactivity and excess body weight are among the primary underlying causes of increases in inflammation.[2,4] This provides reason for concern as fewer people engage in exercise and more are becoming overweight.[5,6] Specifically, time spent participating in physical activity is decreasing in the general public and is being replaced with time spent participating in sedentary behaviors at dramatic levels.[5] Similarly, the intake of dietary fiber, one of the dietary factors that may treat or prevent inflammation, is so low in the United States that it is a public health concern for both adults and children.[7]
Perhaps most concerning is that heightened levels of inflammation have been shown in children.[4,8–12] For example, children who are obese have higher concentrations of inflammatory biomarkers than their normal weight peers.[8,9] In fact, the levels of inflammation in higher risk children may be as much as 8 times that for healthier children.[9] Increased levels of inflammation in children are also related to profiles that are at increased risk for future cardiovascular disease.[4] Inflammation in children is positively associated with elevated levels of insulin, glucose, and total cholesterol.[10–12] Given that inflammation promotes the progression of disease states, it is not surprising that diseases such as type 2 diabetes are on the rise in younger children.[13]
As discussed by Gaesser et al,[14] lifestyle interventions that focus on increasing exercise and improving diet have shown positive outcomes in improving levels of inflammation. This is consistent with the impact that lifestyle interventions have on other diseases such as obesity,[15,16] cardiovascular disease,[15] and type 2 diabetes.[16] The promise of lifestyle interventions has been that patients would engage in long-term behavior change that leads to extended improved health. However, a considerable limitation of lifestyle interventions is the ability to maintain healthy changes in the long term. This has led to the suggestion that lifestyle interventions should focus on the concept of a “small changes approach.”[17] The core of this concept is to promote relatively small, manageable changes that are simple to follow. In turn, it is hypothesized that these easierto-manage small changes, when engaged in the long term, can lead to significant improvements. It is estimated that decreasing one’s caloric intake by 100 calories a day or that taking an additional 2000 to 2500 steps a day could stop weight gain, a first step in reversing the obesity epidemic.[18]Another example of small changes is to encourage patients to lose 5% of their initial body weight as this has been shown to have significant improvements in health instead of focusing on becoming normal weight.[19]
A model for weight reduction has been developed that can be used on an individual or population level.[20] Under this model, a small daily energy gap (ie, as few as 10 kcal per day) may underlie population wide weight gain. It is further postulated that a decrease of approximately 220 kcal per day would be necessary to reverse the obesity epidemic. Although larger changes would be needed for an individual with a higher body mass index, these averaged calculations are representative for the majority of the population. Changes maintained at these levels for 3 years would result in maximum weight change.
Although concepts such as these can be extremely helpful in assisting clinicians to maintain realistic goals for their patients, this is a much different approach than most individuals undergoing treatment have in mind. This is best exemplified in that patients engaged in weight loss programs expect to decrease their weight by approximately 30%.[21] Other examples of patients making large (and in many cases, unmanageable) changes include individuals having adverse reactions to exercise programs or diet plans because they tend to engage in advanced levels of physical activity too quickly or become overly restrictive in their diet. In this way, unrealistic expectations toward lifestyle change can have a negative impact on outcomes. For many individuals, a small change approach is inconsistent with their individual goals. Unrealistic expectations from patients likely result from and are reinforced by multiple factors. One factor that appears to play a critical role in this is the media.[22] The diet industry frequently makes claims of losing weight quickly, easily, and often dramatically. Although these unrealistic expectations may play a role in individuals initiating change,[23] they are also likely to set them up for failure.[24,25] Unrealistic expectations for and unrealistic benefits of weight loss make failures more probable.[24,25] Overall, it is critical that patients understand and become committed to attainable goals and have realistic criteria for success. For the vast majority of patients, goals focusing on “large changes” should be avoided.
Clearly, evidence for a large changes approach has yet to be successful; however, little empirical evidence exists to show that a small changes approach will work either.[18] Although small changes are consistent with behavioral theory, most of the research conducted in this area is done through model simulations and not through actual interventions.[18,20] Interestingly, research with improvements in inflammation is consistent with a small changes approach. Specifically, improvements in markers of inflammation have been shown for individuals engaging in exercise as little as 2 hours per week for 12 weeks[26] or slightly less than 1 hour per week for 6 months.[27]These changes also appear to occur relatively soon (eg, 4 weeks) after engaging in lifestyle exercise,[28] and the benefits of exercise may continue well after the program has been discontinued.[29] Overall, significant improvements in inflammation have been shown with modest changes in lifestyle. These small changes resulted in improved inflammation even without weight loss.[30,31] One of the limitations of an approach that focuses on small changes is that a longer period of time may be needed for the patient to see changes. Even though these changes may result in improved levels of inflammation in a fairly limited time,[28] it may prove difficult to use levels of inflammation as a means of providing patients with feedback on their successes. For example, a patient undergoing a weight loss intervention can be provided almost instant feedback by a change in weight. Small changes that take place on a more physiological level may be more difficult to reinforce. With this limitation notwithstanding, a burgeoning literature is developing that supports the need to focus on small changes in lifestyle interventions. Although most people believe that eating healthier and engaging in exercise is beneficial, too few people actually participate in these behaviors. Evidence demonstrating that minimal changes in exercise and diet may possibly slow disease progression through decreasing inflammation provides additional incentive to engage in these behaviors. It should encourage clinicians and patients alike that more manageable small changes can have a significant impact on health.