Weight loss as a treatment for nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is a chronic liver disease that can progress to cirrhosis and hepatocellular carcinoma. NAFLD has been associated with obesity and other features of the metabolic syndrome, including insulin resistance, impaired glucose tolerance, and dyslipidemia. As a result, and with a lack of other effective treatments, weight loss achieved through lifestyle modifications (diet and exercise) has been promoted as the standard treatment. However, there is very little empiric evidence to support the effectiveness of weight loss for NAFLD. This article reviews the current literature on the effects of weight loss achieved through lifestyle modification or medications on NAFLD. To date, there have been no randomized controlled trials of weight loss interventions on hepatic pathology. Only three published trials (N = 89 subjects), which include a comparison group, have been published. These studies suggest improvement in liver enzymes and/or hepatic pathology; however, direct between group comparisons are lacking. Four small, nonrandomized studies (N = 59 subjects) have evaluated the effect of weight loss achieved with medications (4 of orlistat, 1 of sibutramine) on NAFLD. These suggest some improvement in liver enzymes and histopathology. Finally, a brief review of observational studies on the association between NAFLD pathology or liver enzymes and diet composition suggests a possible role for the manipulation of macronutrients and/or micronutrients in NAFLD treatment. In summary, there is little empiric evidence to support the role of weight loss achieved through lifestyle modification or medication in the treatment of NAFLD. Rigorously conducted, randomized controlled trials are needed in this area.     

Lifestyle modification for the management of obesity

Several expert panels have recommended that obese individuals attempt to lose 10% of their initial body weight through a combination of diet, physical activity, and behavior therapy (frequently referred to as lifestyle modification). This article reviews the short-and long-term results of lifestyle modification and methods to improve them. Randomized controlled trials were examined that compared different diet and activity interventions for inducing and maintaining weight loss. Studies that compared different methods of providing lifestyle modification, including on-site vs. Internet-based delivery, also were examined. A comprehensive lifestyle modification program was found to induce a loss of approximately 10% of initial weight in 16 to 26 weeks of group or individual treatment, delivered on-site. Comprehensive Internet-based programs induced a loss of approximately half this size. Patients' consumption of portion-controlled diets, including liquid meal replacements, was associated with significantly greater short-term weight loss than was the consumption of isocaloric diets comprised of conventional foods. Factors associated with long-term weight control included continued patient-practitioner contact (whether on-site or by e-mail), high levels of physical activity, and the long-term use of pharmacotherapy combined with lifestyle modification. In summary, lifestyle modification induces clinically significant weight loss that is associated with the prevention or amelioration of cardiovascular risk factors.     

Weight loss interventions and nonalcoholic fatty liver disease: Optimizing liver outcomes

The growth in prevalence of obesity, type 2 diabetes and nonalcoholic fatty liver disease (NAFLD) has become one of the most important global health challenges. The three chronic diseases are closely linked in their epidemiology and pathophysiology. Currently, weight loss is the most effective treatment for NAFLD (even in the minority of patients with NAFLD who do not have obesity) and is recommended in all national and international guidelines. Accumulating evidence has shown that weight loss, whether achieved by diet and lifestyle interventions, bariatric surgery or pharmacotherapy, can improve biomarkers of NAFLD, as well as prevent progression and, in some cases, reverse fibrosis. There is a dose dependency of weight loss with NAFLD improvement. Pharmacotherapy with antiobesity medications, alone or in combination with intensive lifestyle interventions or other weight-loss drugs, is closing the efficacy gap between diet and exercise and weight-loss surgery in efficacy at reversing obesity. Given the importance of providing effective weight-loss treatment to patients with NAFLD, weight management services need to be made increasingly available and embedded within hepatology services. This narrative review addresses the evidence that weight loss optimizes liver outcomes in people with NAFLD.     

Role of diet and lifestyle changes in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) has become one of the most common causes of liver disease worldwide and has been recognized as a major health burden. The prevalence of NAFLD has grown proportionally with the rise in obesity, sedentary lifestyle, unhealthy dietary pattern, and metabolic syndrome. Currently, there is no drug therapy that can be formulated for treating NAFLD. A combination of dietary modifications and increased physical activity remains the mainstay of NAFLD management. It is hard to maintain this mode of management; however, it seems to have significant long-term benefits. Furthermore, NAFLD patients, whether obese or not, should be educated that a healthy diet and physical activity have benefits beyond weight reduction. Further large controlled randomized trials are needed in order to identify the best dietary regimen and physical activity in the management of NAFLD patients. This review highlights the role of diet and lifestyle modifications in the management of NAFLD, and focuses on human studies regarding dietary modifications and physical activity.     

Weight maintenance: challenges,tools and strategies for primary care physicians

Obesity is recognized as a chronic disease and one of the major healthcare challenges facing us today. Weight loss can be achieved via lifestyle, pharmacological and surgical interventions, but weight maintenance remains a lifetime challenge for individuals with obesity. Guidelines for the management of obesity have highlighted the role of primary care providers (PCPs). This review examines the long‐term outcomes of clinical trials to identify effective weight maintenance strategies that can be utilized by PCPs. Because of the broad nature of the topic, a structured PubMed search was conducted to identify relevant research articles, peer‐reviewed reviews, guidelines and articles published by regulatory bodies. Trials have demonstrated the benefit of sustained weight loss in managing obesity and its comorbidities. Maintaining 5–10% weight loss for ≥1 year is known to ameliorate many comorbidities. Weight maintenance with lifestyle modification – although challenging – is possible but requires long‐term support to reinforce diet, physical activity and behavioural changes. The addition of pharmacotherapy to lifestyle interventions promotes greater and more sustained weight loss. Clinical evidence and recently approved pharmacotherapy has given PCPs improved strategies to support their patients with maintenance of weight loss. Further studies are needed to assess the translation of these strategies into clinical practice.     

Physical activity as a treatment of non-alcoholic fatty liver disease: A systematic review

AIM: To review the effectiveness of exercise as a therapy for nonalcoholic fatty liver disease (NAFLD) and potential benefits in treating insulin resistance and atherosclerosis.METHODS: Medline (EBSCOhost) and PubMed were searched for English-language randomized controlled trials and prospective cohort studies in human adults aged ≥ 18 which investigated the various effects of exercise alone, a combination of exercise and diet, or exercise and diet coupled with behavioral modification on NAFLD from 2010 to Feburary 2015.RESULTS: Eighteen of 2298 available studies were chosen for critical review, which included 6925 patients. Nine (50%) studies were randomized controlled trials. Five (27.8%) studies utilized biopsy to examine the effects of physical activity on hepatic histology. The most commonly employed imaging modality to determine change in hepatic steatosis was hydrogen-magnetic resonance spectroscopy. Only two studies examined the effects of low impact physical activity for patients with significant mobility limitations and one compared the efficacy of aerobic and resistance exercise. No studies examined the exact duration of exercise required for hepatic and metabolic improvement in NAFLD.CONCLUSION: While exercise improved hepatic steatosis and underlying metabolic abnormalities in NAFLD, more studies are needed to define the most beneficial form and duration of exercise treatment.     

Nutritional and behavioral modification therapies of obesity: facts and fiction

Current practice guidelines for management of overweight and obesity recommend a tripartite treatment - lifestyle modification program of diet, exercise, and behavior therapy for all persons with a body mass index of at least 30 (and those with body mass index 25 plus two weight-related comorbidities). Behavior therapy provides the structure that facilitates meeting goals for energy intake and expenditure. Lately, there has been a shift in focus from behavior change to cognitive change because it improves long-term results of lifestyle modification programs. Weight loss diets based on the amounts of individual macronutrients (high-protein diets, low-fat diets and low-carbohydrate diets, etc.) in the diet are not more effective than 'classical' low-calorie and balanced diets. An exception has been detected only in short-term diets with a low glycemic load. Also, epidemiological studies show that there is an inversely proportional relationship between body weight and Mediterranean diet. Cognitive behavioral therapy based on the Mediterranean diet has proven to be effective in clinical practice with regard to weight loss, body fat distribution, biochemical parameters, blood pressure and simplicity of following the diet.     

Effective strategies for weight loss in post‐partum women: a systematic review and meta‐analysis

Post‐partum weight loss is critical to preventing and managing obesity in women, but the results from lifestyle interventions are variable and the components associated with successful outcomes are not yet clearly identified. This study aimed to identify lifestyle intervention strategies associated with weight loss in post‐partum women. MEDLINE, EMBASE, PubMed, CINAHL and four other databases were searched for lifestyle intervention studies (diet or exercise or both) in post‐partum women (within 12 months of delivery) published up to July 2014. The primary outcome was weight loss. Subgroup analyses were conducted for self‐monitoring, individual or group setting, intervention duration, intervention types, the use of technology as a support, and home‐ or centre‐based interventions. From 12,673 studies, 46 studies were included in systematic review and 32 randomized controlled trials were eligible for meta‐analysis (1,892 women, age 24–36 years). Studies with self‐monitoring had significantly greater weight lost than those without (?4.61 kg [?7.08, ?2.15] vs. ?1.34 kg [?1.66, ?1.02], P = 0.01 for subgroup differences). Diet and physical activity when combined were significantly more effective on weight loss compared with physical activity alone (?3.24 kg [?4.59, ?1.90] vs. ?1.63 kg [?2.16, ?1.10], P < 0.001 for subgroup differences). Lifestyle interventions that use self‐monitoring and take a combined diet‐and‐exercise approach have significantly greater weight loss in post‐partum women.     

The comparative and cumulative effects of a dietary restriction and exercise on weight loss

OBJECTIVE: To assess the independence of changes made in diet and physical activity for weight loss; and, to examine the comparative and cumulative effects of these behavioral changes on weight loss outcomes. DESIGN: The observational study is based on longitudinal data collected from 674 women and 288 men enrolled in a 2-year weight loss program introduced into a managed care setting. MEASUREMENTS: The outcome variable was body mass index (BMI) change from baseline to 2-year follow-up. Primary independent variables were changes in physical activity and dietary fat intake, assessed as continuous measures using the Paffenbarger Physical Activity Questionnaire and Block Fat Screener Questionnaire, respectively. Two-way ANCOVA was used to assess the relative effect on BMI of behavioral changes. RESULTS: Study results showed no preference for diet or physical activity change as a weight loss strategy. For both genders, the relationship between the two behaviors was synergistic rather than compensatory. Examination of the comparative benefits of behavioral changes indicated that, for women and men, restricting fat intake was more effective than increasing exercise for weight loss. While fat restrictions alone contributed to weight loss in both genders, exercise alone provided weight loss benefits to men, only. The cumulative effect of weight loss behaviors varied by gender. In women, an interaction was observed. The response of weight to fat restriction was greater among those who increased their exercise moderately or substantially. In men, there was no interaction; exercise increases helped to offset weight gain or provided small weight loss benefits at all levels of dietary fat change. CONCLUSION: Dietary changes appeared to be more effective than increased physical activity for weight loss. For women, the cumulative effect of concomitant changes in diet and exercise on weight loss was more than additive.     

Dietary strategies to reduce metabolic syndrome

Metabolic syndrome (MetS) is a cluster of metabolic abnormalities characterized by central obesity, dyslipidemias, hypertension, high fasting glucose, chronic low-grade inflammation and oxidative stress. This condition has become an increasing problem in our society where about 34 % of adults are diagnosed with MetS. In parallel with the adult situation, a significant number of children present lipid abnormalities and insulin resistance, which can be used as markers of MetS in the pediatric population. Changes in lifestyle including healthy dietary regimens and increased physical activity should be the first lines of therapy to decrease MetS. In this article, we present the most recent information on successful dietary modifications that can reduce the parameters associated with MetS. Successful dietary strategies include energy restriction and weight loss, manipulation of dietary macronutrients—either through restriction of carbohydrates, fat, or enrichment in beneficial fatty acids, incorporation of functional foods and bioactive nutrients, and adherence to dietary and lifestyle patterns such the Mediterranean diet and diet/exercise regimens. Together, the recent findings presented in this review serve as evidence to support the therapeutic treatment of MetS through diet.     

Alimentary regimen in non-alcoholic fatty liver disease: Mediterranean diet

Non-alcoholic fatty liver disease(NAFLD)is the most common liver disease worldwide.The mechanisms of the underlying disease development and progression are awaiting clarification.Insulin resistance and obesity-related inflammation status,among other possible genetic,dietary,and lifestyle factors,are thought to play the key role.There is no consensus concerning the pharmacological treatment.However,the dietary nutritional management to achieve weight loss is an essential component of any treatment strategy.On the basis of its components,the literature reports on the effectiveness of the Mediterranean diet in reducing cardiovascular risk and in preventing major chronic diseases,including obesity and diabetes.New evidence supports the idea that the Mediterranean diet,associated with physical activity and cognitive behaviour therapy,may have an important role in the prevention and the treatment of NAFLD.     

Non-alcoholic fatty liver disease and associated dietary and lifestyle risk factors

Nonalcoholic fatty liver disease (NAFLD) has emerged as the most common chronic liver disease worldwide with a reported prevalence ranging 20–30% depending on the studied populations. The high prevalence of NAFLD is probably due to the contemporary epidemics of obesity, unhealthy dietary pattern, and sedentary lifestyle. NAFLD patients are at increased risk of cardiovascular and liver related mortality. The cornerstone of any treatment regimen for patients with NAFLD is lifestyle modification focused on weight loss, exercise, and improving insulin sensitivity. The purpose of this review is to outline the effect of diet and lifestyle factors on developing NAFLD.     

Behavioral therapy for management of obesity

Obesity is a major public health problem and is implicated in the rising prevalence of cardiac disease and type 2 diabetes mellitus in India. Management of an obese patient includes therapeutic lifestyle changes of increasing physical activity and reducing calorie intake. This combination can result in about a 10% loss of initial body weight. To reinforce this intervention, behavioral therapy needs to be incorporated into the overall intervention under the belief that obesity is a result of maladaptive eating behaviors and exercise patterns. This review explains the principles of behavioral therapy, including the underlying assumptions and characteristics. The common components of behavioral therapy for obesity are explained. The different settings where behavioral therapy can be administered are mentioned. The review focuses on how behavioral therapy can be incorporated in the routine clinical management of obesity by primary and secondary care physicians who encounter obese patients.     

Current treatment options for the metabolic syndrome

Optional statement The metabolic syndrome is defined as a condition characterized by a set of clinical criteria: insulin resistance, visceral obesity, atherogenic dyslipidemia, and hypertension. The major risk factors leading to the epidemic of this syndrome in the United States are visceral obesity, physical inactivity, and an atherogenic diet. The available current evidence suggests that the first step in management of patients with metabolic syndrome should be focused on lifestyle modifications (eg, weight loss and physical activity). The treatment should be based on two major components: behavioral change to reduce caloric intake and an increase in physical activity. A realistic goal for weight reduction should be 7% to 10% over 6 to 12 months. The general dietary recommendations include low intake of saturated fats, trans fats and cholesterol, and diets with low glycemic index. Soy protein could be more beneficial than animal protein in weight reduction and correction of dyslipidemia. Physical activity is associated with successful weight reduction and these therapeutic lifestyle changes can reduce by half the progression to new-onset diabetes in patients with metabolic syndrome. Physical activity recommendations should include practical, regular, and moderated regimens of exercise, with a daily minimum of 30 to 60 minutes. An equal balance between aerobic exercise and strength training is advised. Medication therapy is a critical step in the management of patients with metabolic syndrome when lifestyle modifications fail to achieve the therapeutic goals. There is no single best therapy and the treatment should consist of treatment of individual component(s). Atherogenic dyslipidemia should be controlled with statins if there is concomitant increase in low-density lipoprotein cholesterol and if indicated with combination therapy, including fibrates, nicotinic acid, bile acid-binding resins, or ezetimibe. Drugs such as thiazolidinediones and renin-angiotensin system blockers are a few of the available agents in this category. Some evidence suggests that angiotensin-converting enzyme inhibitors and β blockers are more beneficial for treatment of hypertension in patients with metabolic syndrome. Patients with metabolic syndrome also have elevations in fibrinogen and other coagulation factors leading to prothrombotic state and aspirin may be beneficial for primary prevention in these patients. The new developments in the treatment of metabolic syndrome with drugs, such as peroxisome proliferator-activated receptor agonists, will broaden the horizons of the current treatment options in metabolic syndrome.     

Lessons from obesity management programmes: greater initial weight loss improves long-term maintenance

It is a common belief that weight loss achieved at a slow rate is better preserved than if the weight is lost more rapidly. However, the literature shows that initial weight loss is positively, not negatively, related to long‐term weight maintenance. There is evidence from randomised intervention trials to support that a greater initial weight loss induced without changes in lifestyle e.g. liquid formula diets or anorectic drugs) improves long‐term weight maintenance, providing it is followed by a 1–2 years integrated weight maintenance programme consisting of lifestyle interventions involving dietary change, nutritional education, behaviour therapy and increased physical activity. In conclusion, we find evidence to suggest that a greater initial weight loss as the first step of a weight management programme may result in improved sustained weight maintenance.     

Have guidelines addressing physical activity been established in nonalcoholic fatty liver disease?

The purpose of this review was to highlight, in relation to the currently accepted pathophysiology of non-alcoholic fatty liver disease (NAFLD), the known exercise habits of patients with NAFLD and to detail the benefits of lifestyle modification with exercise (and/or physical activity) on parameters of metabolic syndrome. More rigorous, controlled studies of longer duration and defined histopathological end-points comparing exercise alone and other treatment are needed before better, evidence-based physical activity modification guidelines can be established, since several questions remain unanswered.     

The DASH Diet and Insulin Sensitivity

Lifestyle modifications, including adoption of the Dietary Approaches to Stop Hypertension (DASH) dietary pattern, weight loss in individuals who are overweight or obese, and physical activity, are effective in the prevention and treatment of hypertension. A healthy lifestyle may also have beneficial effects on metabolic abnormalities, such as insulin resistance, that are associated with high blood pressure. This review examines the independent and combined effects of the DASH diet and weight loss plus exercise on blood pressure and insulin sensitivity, with a focus on recently published results from the ENCORE study. Our data suggest that the DASH eating plan alone lowers blood pressure in overweight individuals with higher than optimal blood pressure, but significant improvements in insulin sensitivity are observed only when the DASH diet is implemented as part of a more comprehensive lifestyle modification program that includes exercise and weight loss.     

Exercise and diet modification in non-obese non-alcoholic fatty liver disease: analysis of biopsies of living liver donors

Background and Aims: We evaluated efficacy of exercise and diet modification for steatosis improvement of non‐obese non‐alcoholic fatty liver disease (NAFLD) patients. Methods: We analyzed retrospectively the clinical and histological parameters of consecutive living liver donors, who experienced repeated liver biopsies due to steatosis and were treated using exercise and diet modification. Results: From 1995 to 2009, among a total of 1365 potential living liver donors with NAFLD seen on the initial liver biopsy, 120 consecutive donors with steatosis ≥ 30% or an estimated donor‐recipient weight ratio < 0.8, underwent exercise and diet modification and received follow‐up liver biopsy at our institution. Median age was 33 years, and median interval between the two consecutive biopsies was 10 weeks (range, 1–39). At the time of initial biopsy, the number of normal body mass index, overweight, and obese donors was 49 (40.8%), 65 (54.2%), and 6 (5.0%), respectively. After lifestyle modification, weight reduction and steatosis improvement were observed in 92 (76.7%) and 103 (85.8%) donors, respectively, at the time of follow‐up biopsy. On multivariate analysis, initially higher steatosis (hazard ratio [HR] 1.03, P = 0.02), total cholesterol reduction ≥ 10% (HR 5.59, P = 0.02), and weight reduction ≥ 5% (HR 6.63, P = 0.03) were significantly associated with ≥ 20% steatosis improvement in 120 donors with NAFLD, after exercise and diet modification. Conclusions: Exercise and diet modification were effective in reducing steatosis in potential living liver donors with non‐obese NAFLD. Total cholesterol reduction ≥ 10% could be used as a non‐invasive predictor for steatosis improvement in liver donors with NAFLD, after exercise and diet modification.