Introduction
Despite advances in technologies designed to facilitate the monitoring and management of blood glucose in patients with diabetes mellitus, avoidance of hypoglycemia continues to be a challenge for patients with type 1, and those with insulin-dependent type 2 diabetes.1 Despite clear guidance on recommended treatment,2 people with diabetes can struggle to self-treat a hypoglycemic episode correctly; some develop hyperglycemia due to overeating, and others experience severe, prolonged hypoglycemia by selecting foods that slow absorption of glucose (eg, peanut butter).3–5 Consequences of inappropriately and inadequately treated hypoglycemia can include seizures, coma, and death.
Under normal circumstances, hypoglycemia is expected to elicit a counter-regulatory hormonal response comprising curtailed pancreatic B-cell insulin secretion, a rise in pancreatic B-cell glucagon and adrenomedullary epinephrine secretion, together with an increased drive to eat.6 7 Hypoglycemic Sprague-Dawley rats have been found to eat more food than their counterparts given a saline as opposed to a glucose solution.8 Earlier research in adults with type 1 diabetes suggested that insulin-induced hypoglycemia elevates desire for foods high in carbohydrate more than it does for desire for low-carbohydrate foods.9
A tendency to seek carbohydrate-loaded food in response to hypoglycemia appears to align with models of regulation of food preferences rooted in glucose metabolism.10 11 These posit that glucose availability plays a fundamental role in the experience of hunger, meal initiation, and satiety. A fall in blood sugar detected by glucose-sensing brain regions12 is argued to prompt the individual to seek foods with a high glycemic load, whereas insulin secretion through glucose absorption to signal satiety and meal termination via the release of glucagon-like peptide-1.11 Hence, it is reasonable to expect that a considerable reduction in the availability of glucose in the bloodstream would increase preference for high-carbohydrate foods until euglycemia is achieved.
However, if glycemia does exert tight control on short-term eating behavior, we would expect people with diabetes to be able to treat their hypoglycemic episodes effectively. The challenge may be partially attributed to the individual’s hypoglycemia awareness.7 13 In the study by Strachan and colleagues,9 the 13 participants living with type 1 diabetes had normal hypoglycemia awareness (experience or perceive symptoms of hypoglycemia) and no history of severe hypoglycemia. Poor glucose control or long-standing recurrent hypoglycemia can impair the ability to detect the onset of hypoglycemia,7 14 and alter the behavioral response. However, previous work has shown that rats with an impaired neuroendocrine counter-regulatory response can also present a hyperphagic response to insulin-induced hypoglycemia, leading the authors to conclude that eating response to hypoglycemia may be regulated by separate neural substrates and pathways to the neuroendocrine response.8
Diabetes education reduces the risk of severe hypoglycemia.15 16 Cognitive deterioration due to the rapid decline in brain glucose availability6 may interfere with/disrupt an individual’s ability to follow advice and self-treat hypoglycemia. Though the effects of glucose on cognitive function are not entirely clear,17 people with diabetes have attributed difficulties in self-treating to ‘confusion’, ‘disorientation’, and ‘panic’.4 Individuals report being unable to restrain their eating to the amounts needed, and to overindulge in foods they like.4 Another study shows hypoglycemia-related increases in food intake in healthy adults without diabetes are due to an increased consumption of foods high in fat content and low glycemic index.18 These findings are inconsistent with the notion of increased preference for carbohydrates triggered automatically by hypoglycemia, and are aligned with critique of the glucostatic theory of appetite control.19 Instead, nutritional knowledge, individual food preferences, and learned eating habits may also be at play in an individual’s behavioral response to hypoglycemia.
Uniquely, the present study revisited the impact of glucose homeostasis on eating predispositions in children and adolescents (age 5–19 years) without diabetes or prior experience of hypoglycemic episodes. To overcome pragmatic and ethical constraints of testing in free living conditions, we administered a computerised forced-choice food preference task used in nutrition research20 to children and adolescents undertaking an insulin tolerance test (ITT) as part of a clinical assessment of pituitary hormone secretory capacity. We hypothesized that participants’ choice of high-carbohydrate foods over low-carbohydrate foods (matched for calories) would increase when in a hypoglycemic state. We additionally hypothesized that the number of gummy bears participants would eat (one of the recommended items to treat hypoglycemia) would be increased during hypoglycemia. Finally, as food preferences and eating habits are shaped by development,20 21 we analyzed whether age moderates the effect of hypoglycemia on eating predispositions.