Cognitive training on eating behaviour and weight loss: A meta‐analysis and systematic review

Abstract

Cognitive deficits play a role in the development and maintenance of overeating and obesity, and cognitive training in obesity refers to a family of interventions aimed at reducing overeating and obesity by improving these cognitive deficits. In this review, we synthesize the current literature on these issues by conducting a meta-analysis of studies investigating the effects of cognitive trainings on eating behaviour and presenting a systematic review of studies investigating the effects of cognitive trainings on weight loss. We examined 66 independent experiments that examined the effects of cognitive training aimed at reducing cognitive bias or improving executive control on eating behaviour and weight loss. Overall, inhibition training, attention bias modification training, and episodic future thinking training significantly influenced eating behaviour; however, approach/avoidance training did not significantly influence eating behaviour. Moderator analyses indicated that the effect of inhibition training on eating behaviour was moderated by training task and food novelty, the effect of approach/avoidance training was moderated by food type, and the effect of episodic future thinking training was moderated by type of episodic future thinking. Literature reviewed on cognitive training and weight loss provided preliminary support for the effects of food-specific inhibition training on weight loss from pre-intervention to post intervention. However, because most of the included studies focused on short-term outcomes in normal-weight samples, longer duration studies in clinical populations (eg, individuals with obesity) are needed to examine the generalizability of these results. KEYWORDS cognitive training, eating behaviour, meta-analysis, weight loss 1 | INTRODUCTION Excess weight has become a cause of growing health care costs and accounts for over 2.8 million deaths per year, 1 emphasizing the need for effective treatment. In order to promote weight loss, interventions such as behavioural interventions or bariatric surgery are frequently implemented. However, the amount of weight loss achieved via behavioural weight loss interventions is, at best, only modest and rarely does it last. 2 Although bariatric surgery is an effective weight loss intervention for severe obesity, it is highly invasive and can result in medical complications. 3 Therefore, it is vital to identify novel, noninvasive interventions that foster weight loss. Recent literature emphasizes the importance of cognitive mechanisms in the regulation of eating behaviour and body weight. 4-7 Manypeople nowadays live in an obesogenic food environment and are constantly exposed to appetitive yet unhealthy foods, especially those that contain much sugar and fat. 8 In such an environment, unhealthy eating behaviour (eg, forgoing healthy foods in favour of inexpensive,

Unchanged food approach‐avoidance behaviour of healthy men after oxytocin administration

“…62 Another meta-analysis investigating 13 AAT interventions found no significant effects of the AAT on eating behaviour, suggesting varying AAT methodology and thus decreased reliability. 63 Second, the present study lacked a non-food control condition with the AAT, making it difficult to determine whether the effects that we saw were specific to food rewards. There was also no clear-cut separation in terms of calories or processed foods or snacks vs main meals, and this should be consider in future studies with respect to stimulus development.…”

“…A meta‐analysis of 29 AAT studies suggested that the instructions given to participants (eg, instructed to focus on task‐relevant content vs to attend to an irrelevant feature) played an important role in the non‐significant overall effects 62 . Another meta‐analysis investigating 13 AAT interventions found no significant effects of the AAT on eating behaviour, suggesting varying AAT methodology and thus decreased reliability 63 . Second, the present study lacked a non‐food control condition with the AAT, making it difficult to determine whether the effects that we saw were specific to food rewards.…”

Beyond inhibitory control training: Inactions and actions influence smartphone app use through changes in explicit liking.

“…As a result, training effects cannot be accounted for by Pavlovian, evaluative, or operant conditioning alone, where objects or behaviors are paired with events with clear evaluative connotations (De Houwer, 2007). Instead, GNG was first introduced as a training of inhibitory control (Houben & Jansen, 2011) and is still presented as such (e.g., Allom et al, 2016;Carbine & Larson, 2019;Forman et al, 2019;Jones et al, 2016;Yang et al, 2019). BEYOND INHIBITORY CONTROL TRAINING 4 According to this account, repeatedly not responding to attractive objects serves as an exercise to train the brain to become better at executing control in order to resist temptations.…”

“…Finally, it is doubtful whether executive control can be trained with such a simple training procedure (Veling et al, 2017). In light of these findings and arguments, the current and consistent portrayal of GNG as an inhibitory control training (e.g., Carbine & Larson, 2019;Forman et al, 2019;Yang et al, 2019) is remarkably tenacious. A lack of convincing evidence for alternative explanations may contribute to this status quo.…”

Interpretation bias modification to reduce body dissatisfaction – a randomized controlled pilot study in women with elevated weight and shape concerns

“…CBM paradigms targeting interpretation bias (CBM-I) foster positive (i.e., unbiased, balanced, or self-serving) interpretations of ambiguous information [18,19]. Despite mixed results in meta-analyses [20,21], CBM-I has shown potential to reduce psychopathology [22]. So far, seven studies have examined CBM-I in the domain of body image/ eating disorders (for review see [19]), of which four studies investigated appearance-based CBM-I approaches [23][24][25][26][27].…”