The Pavlovian power of palatable food: lessons for weight-loss adherence from a new rodent model of cue-induced overeating

Abstract

ObjectiveRelapsing to overeating is a stubborn problem in obesity treatment. We tested the hypothesis that context cues surrounding palatable food (PF) intake have the power to disrupt caloric regulation even of less PF. Context cues are non-food cues that are in the environment where PF is habitually eaten.DesignRats were conditioned to associate intake of Oreo cookies as the PF to cages with distinct context cues that differed from cues in cages were they were only given chow. PF naturally stimulated greater caloric intake. The rats were then tested in the PF cage with only chow available to determine if the PF-paired cues, alone, could elicit overeating of plain chow.SubjectsNon food-deprived female Sprague-Dawley rats.MeasurementsIntake of plain chow under PF-paired cues vs. chow-paired cues was compared. This was also measured in tests that included a morsel of PF as a priming stimulus. We also controlled for any effect of binge-prone vs. binge–resistant status to predict cued-overeating.ResultsRats consumed significantly more chow when exposed to context cues previously paired with PF than with chow (p<0.01). This effect occurred using various cues (e.g., different types of bedding or wallpaper). The effect was strengthened by priming with a morsel of PF (p<0.001) and was unaffected by baseline differences in propensity to binge on PF.ConclusionContext-cues associated with PF intake can drive overeating even of a less PF and abolish the ability of rats to compensate for the calories of a PF primer. Just as drug-associated context cues can reinstate drug-addiction relapse, PF-paired cues may trigger overeating relapses linked to weight regain and obesity. This model should help identify the reflex-like biology that sabotages attempts to adhere to healthy reduced calorie regimens and call greater attention to the cue-factor in the treatment of binge-eating and obesity.

Opiates, overeating and obesity: a psychogenetic analysis

“…56 In addition, a recent study demonstrated that high intake of palatable food was a good predictor of binge eating in animals independent of their susceptibility to gain weight. 57 There is also evidence that satiety regulation of fat intake is less efficient than it is for other macronutrients, suggesting another mechanism whereby a fat preference contributes to overconsumption. 58 Our final hypothesis was also supported by the data.…”

Learned desires

“…Thus, the conditioned cue was able to stimulate food intake even in the absence of a need for additional calories. Other studies have replicated the finding that a distinct cue or context (usually a visual or an auditory cue, or certain environment) that predicted food intake in the past (CS+) can stimulate food consumption, compared with for example 1) a stimulus that was never followed by food intake (CS-), 2) a group of rats that received a training in which presentations of the CSs and USs were unpaired, or 3) a group of rats that received a training in which presentations of the CSs followed (rather than preceded) the USs (Boggiano et al, 2009;Holland, Petrovich, & Gallagher, 2002;Petrovich, Holland, & Gallagher, 2005;Reppucci & Petrovich, 2012;Weingarten, 1984;Zamble, 1973). Thus, conditioned cues have reliably been shown to be able to stimulate food intake in rodents and they support Pavlovian conditioning as mechanism underlying context and cue-elicited eating.…”

“…Although it may seem obvious that this food-abundant environment is associated with increased food cravings and food intake, not so much is known about the precise causal mechanism involved. Especially the role of Pavlovian learning in human eating behaviour has received very little attention in both the scientific literature and obesity treatment plans, despite the fact that several experts have emphasized its importance in overeating and obesity and its contribution to the difficulty in achieving long-term weight loss (Boggiano, Dorsey, Thomas, & Murdaugh, 2009;Bouton, 2011;Jansen, 2010;Jansen, Nederkoorn, & Havermans, 2011). This dissertation aims to address some of the links between appetitive conditioning, eating behaviour, and (un)successful dieting.…”

“…Both the physiological preparatory responses and eating desires are labeled cue reactivity (Jansen, 1998;Jansen, et al, 2010). Classical conditioning studies with animals show that contexts might act as conditioned stimuli as well: sated rats showed an increased food intake in a cage previously associated with eating (Boggiano, Dorsey, Thomas, & Murdaugh, 2009;. The current obesogenic environment provides many opportunities to associate everyday contexts with food intake and therefore is able to elicit frequently recurring cue reactivity and overeating in conditioned contexts.…”

Conquer your cravings

“…salivation), and may stimulate overeating (e.g. Boggiano, Dorsey, Thomas, & Murdaugh, 2009;Bouton, 2011;van den Akker, Havermans, Bouton, & Jansen, 2014;van den Akker, Jansen, Frentz, & Havermans, 2013). In line with these findings, it was found that healthy-weight non-restrained eaters showed increased gastric activity, heart rate and saliva production during exposure to food cues (CSs) (Nederkoorn & Jansen, 2002).…”