Change in craving and frequency of consuming palatable foods for non-homeostatic motives after a gut-cued eating intervention.

INTRODUCTION: Little is known regarding consumption of palatable foods (PFs) for non-homeostatic reasons after weight-loss interventions and if baseline or change in frequency of this kind of eating can predict weight-loss outcomes. Little is also known of the relationship between PF eating for non-homeostatic motives and PF craving. Addressing these gaps is important because cravings and habitual consumption of PFs in the absence of homeostatic need contribute to obesity. METHODS: N = 30 adults with a mean 34.8 BMI completed a seven-response choice version of the PEMS (PEMS-7) before and after Gut-Cued Eating (GCE), an intervention that did not ban PFs but instructed them to eat only when stomach-hungry and stop eating before feeling too full. Photos of PFs were also rated pre- and post-GCE. RESULTS: Frequency of eating PFs for social, reward enhancement, and coping, but not conformity motives, decreased after GCE. The decreases predicted amount of weight loss independent of initial weight and demographics. PF craving also decreased and, while correlated with decreasing PF intake, it did not predict weight loss. DISCUSSION: The study is preliminary because GCE was uncontrolled. However, results warrant a controlled investigation. That craving and frequency of consuming PFs for non-homeostatic motives declined with an intervention that did not ban PFs suggests a method that may voluntarily decrease one's intake of PFs. This should facilitate weight-loss and healthy-weight maintenance. Finally, decreased eating for non-homeostatic motives suggests that individuals were no longer using PFs to cope, socialize, and enhance reward, a change with benefits beyond weight loss.

Effect of transcranial direct current stimulation (tDCS) on food craving and eating when using a control method that minimizes guessing of the real vs. control condition.

PURPOSE: Validation of transcranial direct current stimulation (tDCS) to treat obesity is hampered by evidence that participants can distinguish real from the traditional-control condition. Correctly guessing the real condition precludes knowing if it is neuromodulation or expectation that suppresses food craving and eating. Therefore, this study tested the putative efficacy of tDCS to the dorsolateral prefrontal cortex (DLPFC) to reduce food craving and eating when an alternative control condition was used that would be difficult to distinguish from the real condition. METHODS: N = 28 adults with a 26-50 BMI range received a typical 20-min 2 mA current session of tDCS targeting the DLPFC as the real condition and a same duration/current tDCS session targeting the sensorimotor cortex (SMC), a region not expected to affect appetite, as the control. Food image craving ratings, in-lab food consumption, and momentary ratings of physical sensations were measured. RESULTS: DLPFC failed to reduce food craving and consumption compared to SMC stimulation. When interviewed, 71% of participants were unable to guess real from control conditions. Those who guessed DLPFC tDCS as real attributed their guess to increased number and frequency of sensations. However, their sensation ratings during tDCS did not differ between conditions. CONCLUSIONS: The results question if tDCS suppresses craving and eating at all, or if the DLPFC is the best target to do so. The results also indicate that alternate-site constant stimulation as the control method may strengthen the scientific evaluation of tDCS to treat obesity. LEVEL OF EVIDENCE: Level I, experimental study.