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Western-style diet impairs stimulus control by food deprivation state cues: Implications for obesogenic environments
Sample et. al (2015) addresses the “obesogenic environments” commonly found in the western and westernised societies and the hypothesis that the external cues (that characterise obesogenic environments) associated with highly palatable, energy-dense foods may elicit such powerful changes in appetitive and eating behavior that the internal physiological mechanisms that helps maintain energy balance may become overwhelmed. Sample and others (2015) therefore undertook two experiments to investigate a learning mechanism that may underlie the supposed loss of internal control (relative to external). The first experiment involved rats provided with external stimuli (auditory cues) and varying levels of food deprivation (internal stimuli), both of which could be used to solve a simple discrimination task. Yet, deprivation cues ended up gaining substantial discriminative control over conditioned responding. Whereas, experiment 2 found that in comparison to standard chow, maintenance on a “western-style” diet high in saturated fat and sugar weakened discriminative control by food deprivation cues, but did not impair learning when external cues were also trained as relevant discriminative signals for sucrose. The researchers concluded that eating a western-style diet contributed to a loss of internal control over appetitive behavior relative to external cues, and discussed how interference of hippocampal-dependent learning and memory processes may be the cause of this relative loss of control by food deprivation signals. This would form the basis of a vicious-cycle of excessive consumption, body weight gain, and progreesive cognitive decline that could begin “very early” in life. [NPID: interoception, interoceptive awareness, body image, internal control, control, HDML, hippocampus, Western-style diet, WS diet, cognitive decline]
Year: 2015
