Laboratory‐based interventions targeting food craving: A systematic review and meta‐analysis

This systematic review and meta‐analysis aimed to quantify the effects of laboratory‐based interventions targeting specific mechanisms of food craving, to identify moderators of effects, and to qualitatively summarize findings. The study was conducted and reported according to the Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA) guidelines. Sixty‐nine studies were included in the quantitative synthesis, and separate meta‐analyses were conducted for the outcomes self‐reported craving and objective food intake. Results show small to medium positive effects across specific craving interventions on both outcomes. Effect sizes were partly moderated by intervention type. The most effective intervention regarding food intake was in sensu cue exposure. For subjective craving, the most robust evidence was found for beneficial effects of cognitive regulation strategies (ie, reappraisal, suppression, and distraction). Results further indicate that training inhibitory control through behavioral inhibition might be more effective than approach‐avoidance training when considering its effect on subjective craving and food intake. People with external eating habits, overeating, or loss‐of‐control eating might benefit from these types of specific craving interventions. Future research should focus on long‐term effects, transferability, and effectiveness in clinical samples.     

Evaluation of an approach–avoidance training intervention for children and adolescents with obesity: A randomized placebo‐controlled prospective trial

This study evaluated the efficacy of approach–avoidance training as an additional treatment for children and adolescents with obesity seeking inpatient treatment. Two hundred thirty‐two participants (8–16 years, 53.9% girls) were randomly assigned either to multisession approach–avoidance (IG) or to placebo training (CG). As outcomes, cognitive biases post intervention, body mass index, eating behaviour, food intake, self‐regulation, and weight‐related quality of life were assessed, also at 6‐ and 12‐month follow‐up. Modification of approach–avoidance bias was observed, but lacked in transfer over sessions and in generalization to attention and association bias. After 6 months, the IG reported less “problematic” food consumption, higher self‐regulation, and higher quality of life; effects did not persist until the 12‐month follow‐up; no significant interaction effects were observed regarding weight course. Despite there was no direct effect on weight course, approach–avoidance training seems to be associated with promising effects on important pillars for weight loss. Further research concerning clinical effectiveness is warranted.     

Expressive Suppression of Emotions and Overeating in Individuals with Overweight and Obesity

Emotions have a considerable impact on eating behaviour; however, research addressing emotion regulation in obesity is rare. The present study is the first to investigate the association between emotional suppression and overeating in individuals with overweight. In total, 314 participants including 190 individuals with obesity filled in a cross‐sectional online survey, which assessed emotional suppression, eating behaviour and psychopathology. A hierarchical linear regression analysis was conducted to identify factors associated with overeating. Individuals with obesity reported more frequent overeating compared with individuals without obesity. The habitual use of emotional suppression was associated with more overeating; however, this link was moderated by increased body mass index (BMI). The results suggest that suppression of emotional expression contributes to overeating and is maladaptive especially in individuals with obesity. Further research should longitudinally investigate the predictive value of emotional suppression on overweight, as the training of emotion regulation could contribute to treating obesity. Copyright © 2016 John Wiley & Sons, Ltd and Eating Disorders Association.     

Improving Inhibitory Control Abilities (ImpulsE)—A Promising Approach to Treat Impulsive Eating?

Although there is preliminary evidence that inhibitory control training improves impulsive eating, less is known about the effects on eating behaviour and weight loss in clinical samples. Sixty‐nine treatment‐seeking adults with obesity (binge‐eating disorder 33.3%; other specific feeding and eating disorders 40.6%) were randomly blockwise allocated to ImpulsE, an intervention to improve inhibitory control and emotion regulation abilities or a guideline‐appropriate cognitive behavioural therapy (CBT)‐based treatment as usual. Self‐reported and performance‐based impulsivity, eating disorder pathology and BMI were compared at baseline (T1), post‐treatment (T2) and 1‐ or 3‐month follow‐up. ImpulsE led to better food‐specific inhibition performance (p = .004), but groups did not differ regarding improvements in global Eating Disorder Examination Questionnaire (EDE‐Q) score at T2. At 3‐month follow‐up, binge eaters benefited most from ImpulsE (p = .028) and completers of ImpulsE demonstrated a significantly greater weight reduction (p = .030). The current findings propose ImpulsE as a promising approach to treat obesity, illustrating acceptability and additional benefits for course of weight. Copyright © 2017 John Wiley & Sons, Ltd and Eating Disorders Association.     

Smartphone‐based cognitive bias modification training improves healthy food choice in obesity: A pilot study

Obesity is partly driven by unhealthy food choices underpinned by cognitive biases, including approach bias (a tendency to move towards food cues) and delay discounting (a preference for immediate rewards). Cognitive training strategies aimed at modifying these biases, namely, approach–avoidance training (AAT) and episodic future thinking (EFT), may improve food choice. This pilot randomised trial examined the effect of these two trainings, delivered daily for 1 week via smartphone apps, on approach bias for healthy/unhealthy foods, delay discounting for money/food, and hypothetical food choice. Sixty overweight/obese participants (18–45 years) were randomly allocated to AAT, EFT, or control. Outcomes were measured at pretraining, posttraining, and 6‐week follow‐up. AAT reduced approach bias for unhealthy food and increased healthy food choice. However, EFT did not affect delay discounting or food choice. We conclude that AAT is useful for improving food choice in obesity and that smartphones are a feasible, engaging way to deliver training.     

Food Addiction in Overweight and Obese Adolescents Seeking Weight‐loss Treatment

Some forms of overeating closely resemble addictive behaviour. The Yale Food Addiction Scale (YFAS) was developed to measure such addiction‐like eating in humans and has been employed in numerous studies for examining food addiction in adults. Yet, little is known about food addiction in children and adolescents. Fifty adolescents were recruited at the beginning of treatment in a weight‐loss hospital and completed the YFAS among other questionnaires. Nineteen participants (38%) received a YFAS diagnosis, who did not differ in age, body mass and gender distribution from those not receiving a diagnosis. However, those with food addiction reported more binge days, more frequent food cravings, higher eating, weight and shape concerns, more symptoms of depression and higher attentional and motor impulsivity. Eating restraint and nonplanning impulsivity did not differ between groups. Results replicate findings from studies in obese adults such that food addiction is not related to age, gender, body mass or eating restraint, but to higher eating pathology, more symptoms of depression and higher impulsivity. Furthermore, results highlight that particularly attentional impulsivity is related to ‘food addiction’. Addiction‐like eating appears to be a valid phenotype in a substantial subset of treatment‐seeking, obese adolescents. Copyright © 2015 John Wiley & Sons, Ltd and Eating Disorders Association.     

Behavioural implications of traditional treatment and closed‐loop automated insulin delivery systems in Type 1 diabetes: applying a cognitive restraint theory framework

As the prevalence of obesity in Type 1 diabetes rises, the effects of emerging therapy options should be considered in the context of both weight and glycaemic control outcomes. Artificial pancreas device systems will ‘close the loop’ between blood glucose monitoring and automated insulin delivery and may transform day‐to‐day dietary management for people with Type 1 diabetes in multiple ways. In the present review, we draw directly from cognitive restraint theory to consider unintended impacts that closed‐loop systems may have on ingestive behaviour and food intake. We provide a brief overview of dietary restraint theory and its relation to weight status in the general population, discuss the role of restraint in traditional Type 1 diabetes treatment, and lastly, use this restraint framework to discuss the possible behavioural implications and opportunities of closed‐loop systems in the treatment of Type 1 diabetes. We hypothesize that adopting closed‐loop systems will lift the diligence and restriction that characterizes Type 1 diabetes today, thus requiring a transition from a restrained eating behaviour to a non‐restrained eating behaviour. Furthermore, we suggest this transition be leveraged as an opportunity to teach people lifelong eating behaviour to promote healthy weight status by incorporating education and cognitive reappraisal. Our aim was to use a transdisciplinary approach to highlight critical aspects of the emerging closed‐loop technologies relating to eating behaviour and weight effects and to promote discussion of strategies to optimize long‐term health in Type 1 diabetes via two key outcomes: glycaemic control and weight management.     

A Pavlovian approach to the problem of obesity

During the past 15-20 y, the incidence of overweight and obesity in the United States has grown rapidly. The processes that underlie this alarming trend remain largely unspecified. We hypothesize that degradation of the ability to use certain orosensory cues to predict the caloric consequences of intake may contribute to overeating and excessive weight gain. The results of two preliminary studies with rats are consistent with this hypothesis. In one study, the ability of rat pups to regulate their caloric intake after consuming a novel high-calorie, sweet food was disrupted if they had received prior training with sweet tastes that failed to predict the caloric consequences of eating. Another study found that altering the normal predictive relationship between food viscosity and calories led to increased body weight in adult rats. Dietary factors that degrade the relationship between sweet tastes, food viscosity and calories may contribute to overeating and weight gain.     

Obesity,intentional weight loss and physical disability in older adults

We examine obesity, intentional weight loss and physical disability in older adults. Based on prospective epidemiological studies, body mass index exhibits a curvilinear relationship with physical disability; there appears to be some protective effect associated with older adults being overweight. Whereas the greatest risk for physical disability occurs in older adults who are ≥class II obesity, the effects of obesity on physical disability appears to be moderated by both sex and race. Obesity at age 30 years constitutes a greater risk for disability later in life than when obesity develops at age 50 years or later; however, physical activity may buffer the adverse effects obesity has on late life physical disability. Data from a limited number of randomized clinical trials reinforce the important role that physical activity plays in weight loss programmes for older adults. Furthermore, short‐term studies have found that resistance training may be particularly beneficial in these programmes as this mode of exercise attenuates the loss of fat‐free mass during caloric restriction. Multi‐year randomized clinical trials are needed to examine whether weight loss can alter the course of physical disablement in aging and to determine the long‐term feasibility and effects of combining resistance exercise with weight loss in older adults.     

The neurocognitive connection between physical activity and eating behaviour

As obesity rates increase worldwide, healthcare providers require methods to instill the lifestyle behaviours necessary for sustainable weight loss. Designing effective weight‐loss interventions requires an understanding of how these behaviours are elicited, how they relate to each other and whether they are supported by common neurocognitive mechanisms. This may provide valuable insights to optimize existing interventions and develop novel approaches to weight control. Researchers have begun to investigate the neurocognitive underpinnings of eating behaviour and the impact of physical activity on cognition and the brain. This review attempts to bring these somewhat disparate, yet interrelated lines of literature together in order to examine a hypothesis that eating behaviour and physical activity share a common neurocognitive link. The link pertains to executive functions, which rely on brain circuits located in the prefrontal cortex. These advanced cognitive processes are of limited capacity and undergo relentless strain in the current obesogenic environment. The increased demand on these neurocognitive resources as well as their overuse and/or impairment may facilitate impulses to over‐eat, contributing to weight gain and obesity. This impulsive eating drive may be counteracted by physical activity due to its enhancement of neurocognitive resources for executive functions and goal‐oriented behaviour. By enhancing the resources that facilitate ‘top‐down’ inhibitory control, increased physical activity may help compensate and suppress the hedonic drive to over‐eat. Understanding how physical activity and eating behaviours interact on a neurocognitive level may help to maintain a healthy lifestyle in an obesogenic environment.     

Dietary restraint and self-regulation in eating behavior

Self-control is generally viewed as highly desirable. In the eating behavior domain, however, the dominance of restraint theory has made the proposition that individuals should attempt to control their eating more controversial. This review discusses evidence from the dietary restraint literature and from studies of self-regulation processes to examine how far self-imposed control around food can be seen as beneficial for effective weight management. Epidemiological and field study evidence provides little support for the proposition that restrained eating causes disinhibited eating patterns. Restraint is often initiated as a response to weight gain, and the co-occurrence of disinhibited and restrained eating patterns on an individual level might better be explained by restraint acting as a marker for overeating tendencies. A sustained effort to monitor and control food intake characterizes successful long-term weight maintenance, suggesting that self-regulation in the eating domain is essential for those with a tendency to gain weight. Evidence from the literature on cognitive self-regulation suggests that there may be potential for people to learn to self-regulate better, both through training and controlled exposure techniques. Integration of the disparate theories of self-regulation is needed to identify the best ways of promoting self-regulation in order to support effective weight control, both in clinical and community settings.     

Functional neuroimaging: a new generation of human brain studies in obesity research

Obesity is predominantly caused by overeating, an abnormal behaviour for which there is no unequivocal neurophysiological explanation. Functional neuroimaging techniques, such as positron emission tomography (PET) and functional magnetic resonance imaging (fMRI), have recently emerged as new tools to search for regions of the brain that are involved in the regulation of eating behaviours and those that are involved in the pathophysiology of obesity. Using these techniques, a limited number of studies have provided the first in vivo images of the human hypothalamic response to nutritional stimuli and revealed the complexity of the human brain response to hunger, taste, and satiation. Selective differences have been reported in the functional architecture of the brain of obese and lean individuals. We discuss current use and possible future developments of functional neuroimaging applied to obesity research. We conclude that functional neuroimaging provides an increasingly important tool for investigating how different regions of the brain work in concert to orchestrate normal eating behaviours and how they conspire to produce obesity and other eating disorders.     

Eating behaviors in relation to gestational weight gain and postpartum weight retention: A systematic review

Preventing obesity is of utmost public health importance. This paper systematically reviews associations between eating behaviors and peripartum weight change. This knowledge is crucial in the development of interventions that reduce long‐term obesity, often triggered and boosted in the peripartum. Through MEDLINE, EMBASE, and Web of Science, we identified 20 studies that fulfilled inclusion criteria: studies on food cravings, disinhibition, restrained, external, emotional, uncontrolled, intuitive, or mindful eating in relation to gestational or postpartum weight among adult women. Higher gestational weight gain was associated with lower intuitive eating (in 3/3 studies) and higher restrained eating (in 4/11 studies), external eating (in 2/2 studies), emotional eating (in 3/4 studies), food cravings (in 3/3 studies), and disinhibition (in 1/3 studies). No association with uncontrolled eating was found (in one study). No studies on mindful eating and gestational weight were identified. Higher postpartum weight loss was associated with higher restrained (in 2/4 studies) and intuitive eating (in 1/1 study). No associations between postpartum weight and food cravings, disinhibition, and mindful eating were found. No studies on external, emotional and uncontrolled eating, and postpartum weight were identified. Concluding, certain eating behaviors might be related to peripartum weight change.     

Comparing the effects of food restriction and overeating on brain reward systems

Both caloric restriction and overeating have been shown to affect neural processes associated with reinforcement. Both preclinical and some clinical studies have provided evidence that food restriction may increase reward sensitivity, and while there are mixed findings regarding the effects of overeating on reward sensitivity, there is strong evidence linking this behavior with changes in reward-related brain regions. Evidence of these changes comes in part from findings that show that such eating patterns are associated with increased drug use. The data discussed here regarding the differential effects of various eating patterns on reward systems may be particularly relevant to the aging population, as this population has been shown to exhibit altered reward sensitivity and decreased caloric consumption. Moreover, members of this population appear to be increasingly affected by the current obesity epidemic. Food, like alcohol or drugs, can stimulate its own consumption and produce similar neurochemical changes in the brain. Age-related loss of appetite, decreased eating, and caloric restriction are hypothesized to be associated with changes in the prevalence of substance misuse, abuse, and dependence seen in this cohort.     

Effect of changes to the school food environment on eating behaviours and/or body weight in children: a systematic review

Previous school obesity‐prevention reviews have included multi‐component interventions. Here, we aimed to review the evidence for the effect of isolated food environment interventions on both eating behaviours (including food purchasing) and/or body weight. Five electronic databases were searched (last updated 30 November 2013). Of the 1,002 unique papers identified, 55 reported on school food environment changes, based on a review of titles and abstracts. Thirty‐seven further papers were excluded, for not meeting the inclusion criteria. The final selection consisted of 18 papers (14 United States, 4 United Kingdom). Two studies had a body mass index (BMI) outcome, 14 assessed purchasing or eating behaviours and two studies assessed both weight and behaviour. Seventeen of 18 papers reported a positive outcome on either BMI (or change in BMI) or the healthfulness of food sold or consumed. Two studies were rated as strong quality and 11 as weak. Only three studies included a control group. A school environment supportive of healthy eating is essential to combat heavy marketing of unhealthy food. Modification of the school food environment (including high‐level policy changes at state or national level) can have a positive impact on eating behaviours. A need exists, however, for further high‐quality studies.     

Mindfulness‐based interventions for obesity‐related eating behaviours: a literature review

Mindfulness‐based interventions (MBIs) targeting eating behaviours have gained popularity in recent years. A literature review was conducted to determine the effectiveness of MBIs for treating obesity‐related eating behaviours, such as binge eating, emotional eating and external eating. A search protocol was conducted using the online databases Google Scholar, PubMed, PsycINFO and Ovid Healthstar. Papers were required to meet the following criteria to be included in this review: (i) describe a MBI or the use of mindfulness exercises as part of an intervention; (ii) include at least one obesity‐related eating behaviour as an outcome; (iii) include quantitative outcomes; and (iv) be published in English in a peer‐reviewed journal. A total of N = 21 papers were included in this review. Interventions used a variety of approaches to implement mindfulness training, including combined mindfulness and cognitive behavioural therapies, mindfulness‐based stress reduction, acceptance‐based therapies, mindful eating programmes, and combinations of mindfulness exercises. Targeted eating behaviour outcomes included binge eating, emotional eating, external eating and dietary intake. Eighteen (86%) of the reviewed studies reported improvements in the targeted eating behaviours. Overall, the results of this first review on the topic support the efficacy of MBIs for changing obesity‐related eating behaviours, specifically binge eating, emotional eating and external eating.     

To Go or Not to Go: A Proof of Concept Study Testing Food‐Specific Inhibition Training for Women with Eating and Weight Disorders

Inefficient food‐specific inhibitory control is a potential mechanism that underlies binge eating in bulimia nervosa and binge eating disorder. Go/no‐go training tools have been developed to increase inhibitory control over eating impulses. Using a within‐subjects design, this study examined whether one session of food‐specific go/no‐go training, versus general inhibitory control training, modifies eating behaviour. The primary outcome measure was food consumption on a taste test following each training session. Women with bulimia nervosa and binge eating disorder had small non‐significant reductions in high‐calorie food consumption on the taste test following the food‐specific compared with the general training. There were no effects on eating disorder symptomatic behaviour (i.e. binge eating/purging) in the 24 h post‐training. The training task was found to be acceptable by the clinical groups. More research is needed with larger sample sizes to determine the effectiveness of this training approach for clinical populations. Copyright © 2017 John Wiley & Sons, Ltd and Eating Disorders Association.     

Selected eating behaviours and excess body weight: a systematic review

The relationship between obesity and the intake of macronutrients and specific foods is uncertain. Thus, there is growing interest in some eating behaviours because they may reflect the joint effect of several foods and nutrients and, thus, increase the likelihood of finding a link to obesity. This study examined the association between selected eating behaviours and excess weight in the general population throughout a systematic review of publications written in English, Spanish or Portuguese identified in a PubMed search up to 31 December 2010. We included 153 articles, 73 of which have been published since 2008. Only 30 studies had a prospective design; of these, 15 adjusted for sociodemographic variables, physical activity and energy or food intake. Moreover, definitions of eating behaviours varied substantially across studies. We found only small or inconsistent evidence of a relationship between excess weight and skipping breakfast, daily eating frequency, snacking, irregular meals, eating away from home, consumption of fast food, takeaway food intake, consumption of large food portions, eating until full and eating quickly. In conclusion, this review highlights the difficulty in measuring human behaviour, and suggests that a more systematic approach is needed for capturing the effects of eating behaviours on body weight.     

Disinhibition: its effects on appetite and weight regulation

Over the past 30 years, the understanding of eating behaviour has been dominated by the concept of dietary restraint. However, the development of the Three Factor Eating Questionnaire introduced two other factors, Disinhibition and Hunger, which have not received as much recognition in the literature. The objective of this review was to explore the relationship of the Disinhibition factor with weight regulation, food choice and eating disorders, and to consider its aetiology. The review indicates that Disinhibition is an important eating behaviour trait. It is associated not only with a higher body mass index and obesity, but also with mediating variables, such as less healthful food choices, which contribute to overweight/obesity and poorer health. Disinhibition is also implicated in eating disorders and contributes to eating disorder severity. It has been demonstrated that Disinhibition is predictive of poorer success at weight loss, and of weight regain after weight loss regimes and is associated with lower self-esteem, low physical activity and poor psychological health. Disinhibition therefore emerges as an important and dynamic trait, with influences that go beyond eating behaviour and incorporate other behaviours which contribute to weight regulation and obesity. The characteristics of Disinhibition itself therefore reflect many components representative of a thrifty type of physiology. We propose that the trait of Disinhibition be more appropriately renamed as 'opportunistic eating' or 'thrifty behaviour'.