App-based food Go/No-Go training: User engagement and dietary intake in an opportunistic observational study.

Food Go/No-Go training aims to alter implicit food biases by creating associations between perceiving unhealthy foods and withholding a dominant response. Asking participants to repeatedly inhibit an impulse to approach unhealthy foods can decrease unhealthy food intake in laboratory settings. Less is known about how people engage with app-based Go/No-Go training in real-world settings and how this might relate to dietary outcomes. This pragmatic observational study investigated associations between the number of completed app-based food Go/No-Go training trials and changes in food intake (Food Frequency Questionnaire; FFQ) for different healthy and unhealthy food categories from baseline to one-month follow-up. In total, 1234 participants (m(BMI) = 29 kg/m2, m(age) = 43years, 69% female) downloaded the FoodT app and completed food-Go/No-Go training at their own discretion (mean number of completed sessions = 10.7, sd = 10.3, range: 1-122). In pre-registered analyses, random-intercept linear models predicting intake of different foods, and controlled for baseline consumption, BMI, age, sex, smoking, metabolic syndrome, and dieting status, revealed small, significant associations between the number of completed training trials and reductions in unhealthy food intake (b = -0.0005, CI95= [-0.0007;-0.0003]) and increases in healthy food intake (b = 0.0003, CI95 = [0.0000; 0.0006]). These relationships varied by food category, and exploratory analyses suggest that more temporally spaced training was associated with greater changes in dietary intake. Taken together, these results imply a positive association between the amount of training completed and beneficial changes in food intake. However, the results of this pragmatic study should be interpreted cautiously, as self-selection biases, motivation and other engagement-related factors that could underlie these associations were not accounted for. Experimental research is needed to rule out these possible confounds and establish causal dose-response relationships between patterns of engagement with food Go/No-Go training and changes in dietary intake.

The dynamics of decision-making in weight loss and maintenance: a qualitative enquiry.

BACKGROUND: Behavioural approaches to weight loss are often initially successful but less so in the longer term, as some people maintain the necessary behaviour changes while others do not. This study aimed to derive possible explanations for this using a qualitative approach with a view to improving intervention effectiveness. METHODS: Thirty-six participants in a development and feasibility study for a weight loss and maintenance intervention (called SkiM) were interviewed three times over 18 months regarding their experiences before, during and after the intervention. Data were analysed thematically. The accounts of those who were more and less successful in terms of longer term weight loss were compared, and a conceptual model linking the main analytic themes was developed. RESULTS: Five interpretative themes were generated: encountering and managing key situations; the impact of emotion; the source of control; personal values; and acquiring knowledge and skills. These themes were linked through a model of decision-making during key situations. In this model, behavioural decisions emerge from a dynamic interplay between several drivers: emotional state and needs, perceived control, personal values, the individual's knowledge and skills, and their existing habits. The individual's response in key situations generates experiential learning that can influence decisional dynamics in similar situations in future. These dynamics appeared to differ between participants, and between those who were more and less successful in weight management. CONCLUSIONS: Our analysis and model of decision-making during weight-management have implications for the development and delivery of behavioural weight management interventions. By helping individuals to identify the drivers of their decision-making in key situations, and equipping them to manage these drivers, programmes may enhance their capacity to sustain the behaviour changes needed for long-term weight loss.