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

Abstract

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.

FIGURE 1

Schema of the two types of eaters outlined by cognitive restraint theory: the non-restrained eater and the restrained eater. In the non-restrained eater (top), eating is initiated by the aversive quality of hunger and is terminated by the aversive quality of hunger. Within the bracket of hunger and satiety, there is a zone of relative ‘biological indifference,’ where eating is driven by external and psychological factors. In the restrained eaters (bottom), such as individuals who are dieters or who have Type 1 diabetes, there are several key differences: 1) hunger and satiety signalling is disrupted where satiety thresholds are increased; 2) there is a cognitive dietary boundary (either self-imposed or medically imposed). When this diet boundary is exceeded by a ‘preload’ of food or another dietary disinhibition, restrained eaters continue to eat until they reach satiety (which is higher than that of a normal eater). When this boundary is removed (in hypoglycaemia for example, or using the flexible closed-loop systems), they may similarly overeat. Grey arrows represent typical ‘ideal’ food intake and black arrows represent typical food intake in episodes of ‘overeating.’

FIGURE 2

(a) Traditional Type 1 diabetes treatment: At diagnosis with Type 1 diabetes, there is transition into a state of cognitive dietary restraint that is compounded by introduction of nutritional guidelines, carbohydrate counting, eating in the absence of hunger, intense self-regulation, and dietary restraint. (b) Transition to be navigated with introduction of closed-loop systems: the flexibility lent by the closed-loop system will remove rigid eating patterns and lift the boundary of cognitive dietary restraint. We suggest this transition be leveraged as an opportunity to teach persons lifelong eating behaviour to promote healthy weight status by incorporating education and cognitive reappraisal. (c) In the absence of cognitive dietary restraint, eating behaviour should resemble non-restrained eaters, including increased flexibility, intuitive eating, and restored hunger and satiety signalling.