It's craving time: time of day effects on momentary hunger and food craving in daily life.

OBJECTIVE: A key determinant of food intake besides hunger is food craving, which refers to an intense desire to consume a specific food. Although they commonly co-occur, they are conceptually different and their dissociation is thought to underlie unhealthy eating (e.g., eating in the absence of hunger). To date, we know almost nothing about their coherence (or dissociation) in daily life or about the role of time of day and different food types. METHODS: The present investigation assessed both hunger and food craving for several food categories in daily life using smartphone-based ecological momentary assessment. Across three independent studies (n = 50, n = 51, and n = 59), participants received five or six prompts a day and reported their momentary hunger and desire for tasty food (a subcomponent of food craving). RESULTS: Consistent across studies, hunger and desire for tasty food exhibited largely similar patterns throughout the day with two peaks (roughly corresponding to lunch and dinner). Examining more specific food categories, study 3 found that although desire for main meal-type foods had a two-peak pattern in coherence with hunger, this pattern was different for snack-type foods: Desire for fruits decreased, whereas desire for sweets and salty snacks increased throughout the day with less coherence with hunger. CONCLUSIONS: These findings suggest that dissociations between hunger and craving are found only for snack-type foods, whereas hunger and general food cravings cohere strongly. Interventions addressing snacking may take these circadian patterns of food cravings into account.

Improvement of Interoceptive Processes after an 8-Week Body Scan Intervention.

Objective: Interoceptive processes are defined as ability to detect sensations arising within the body. There is a growing body of research investigating ways of improving interoceptive processes. One promising approach increasing the attention to bodily sensations is the body scan (BS), a method stemming from mindfulness-based stress reduction. Research so far revealed only heterogenous findings of meditational practice and mindfulness-based stress reduction on interoceptive processes. Even more importantly, there is no study considering the effect of an 8-week BS intervention on interoceptive processes and the distinguishable subdomains of interoception. Therefore, the main objective of this research is to examine the effects of a BS intervention on different interoceptive subdomains over 8 weeks of training in two different samples. Methods: In study 1, healthy participants executed a 20 min standardized audiotaped BS in the BS intervention group (n = 25) each day over 8 weeks. The control group (n = 24) listened to an audio book for the same amount of time. In study 2, the BS group (n = 18) was compared to an inactive control group (n = 18). In both studies, three measurement points were realized and interoceptive accuracy (IAc) - using a heartbeat perception task - as well as interoceptive sensibility (IS) - using confidence ratings for the heartbeat perception task and the subscale 'interoceptive awareness' of the Eating Disorder Inventory-2 (EDI-2) - were assessed. Results: In study 1, we found, as a descriptive trend, IAc and confidence ratings to be increased irrespective of the condition. However, post hoc analysis revealed a significant improvement of IAc between T1 and T3 in the BS intervention only. IS revealed to be unaffected by the interventions. In study 2, we observed a significant positive effect of the BS intervention on IAc and confidence ratings compared to the inactive controls. As in study 1, IS (EDI-2) was unaffected by the intervention. Discussion: The results highlight the fact that interoception can be improved by long-term interventions focusing on bodily signals. Further studies might focus on clinical samples showing deficits in interoceptive processes and could use other bodily systems for measurement (e.g., respiratory signals) as well methods manipulating body ownership.

Interoceptive Processes in Anorexia Nervosa in the Time Course of Cognitive-Behavioral Therapy: A Pilot Study.

OBJECTIVE: Previous studies report reduced interoceptive abilities in anorexia nervosa (AN) using various methods. Recent research suggests that different levels of interoceptive processes aiming at different subdomains of interoceptive abilities must be further distinguished as these levels can be differentially affected. Two important levels refer to interoceptive accuracy (IA) derived from objective performance tasks such as the heartbeat detection task and interoceptive sensibility (IS) as assessed by self-report. There is a lack of studies investigating both IA and IS in AN and examining them in the time course of therapy. The aim of this pilot study was to evaluate the different interoceptive processes - especially IA and IS - in the time course of therapy. METHODS: Fifteen patients with AN (restricting type) from the Psychosomatic Clinic in Windach were investigated three times (T1, T2, T3) during a standardized cognitive-behavioral therapy and compared with 15 matched healthy controls assessed at Ulm University in a comparable design. All participants performed the heartbeat detection task examining IA and completed standard psychological assessments including an assessment of IS. RESULTS: Patients with AN showed a significantly decreased weight, higher levels of depression, and both reduced IA and IS compared to healthy controls at T1. Following therapy, patients recovered in terms of weight and depression symptomatology. A descriptive trend for recovering from IA and IS was observed. DISCUSSION: Our findings suggest that interoceptive deficits are present in recovered patients. Therefore, further investigations are needed with more patients, differentiating between relapsed and recovered patients, and more specific training methods to improve interoceptive processes.