Modeling health gains and cost savings for ten dietary salt reduction targets.

BACKGROUND: Dietary salt reduction is included in the top five priority actions for non-communicable disease control internationally. We therefore aimed to identify health gain and cost impacts of achieving a national target for sodium reduction, along with component targets in different food groups. METHODS: We used an established dietary sodium intervention model to study 10 interventions to achieve sodium reduction targets. The 2011 New Zealand (NZ) adult population (2.3 million aged 35+ years) was simulated over the remainder of their lifetime in a Markov model with a 3 % discount rate. RESULTS: Achieving an overall 35 % reduction in dietary salt intake via implementation of mandatory maximum levels of sodium in packaged foods along with reduced sodium from fast foods/restaurant food and discretionary intake (the "full target"), was estimated to gain 235,000 QALYs over the lifetime of the cohort (95 % uncertainty interval [UI]: 176,000 to 298,000). For specific target components the range was from 122,000 QALYs gained (for the packaged foods target) down to the snack foods target (6100 QALYs; and representing a 34-48 % sodium reduction in such products). All ten target interventions studied were cost-saving, with the greatest costs saved for the mandatory "full target" at NZ$1260 million (US$820 million). There were relatively greater health gains per adult for men and for Maori (indigenous population). CONCLUSIONS: This work provides modeling-level evidence that achieving dietary sodium reduction targets (including specific food category targets) could generate large health gains and cost savings for a national health sector. Demographic groups with the highest cardiovascular disease rates stand to gain most, assisting in reducing health inequalities between sex and ethnic groups.

The use of a wearable camera to capture and categorise the environmental and social context of self-identified eating episodes.

Research investigating the influence of the environmental and social factors on eating behaviours in free-living settings is limited. This study investigates the utility of using wearable camera images to assess the context of eating episodes. Adult participants (N = 40) wore a SenseCam wearable camera for 4 days (including 1 familiarisation day) over a 15-day period in free-living conditions, and had their diet assessed using three image-assisted multiple-pass 24-hour dietary recalls. The images of participants' eating episodes were analysed and annotated according to their environmental and social contexts; including eating location, external environment (indoor/outdoor), physical position, social interaction, and viewing media screens. Data for 107 days were used, with a total of 742 eating episodes considered for annotation. Twenty nine per cent (214/742) of the episodes could not be categorised due to absent images (12%, n = 85), dark/blurry images (8%, n = 58), camera not worn (7%, n = 54) and for mixed reasons (2%, n = 17). Most eating episodes were at home (59%) and indoors (91%). Meals at food retailers were 24.8 minutes longer (95% CI: 13.4 to 36.2) and were higher in energy (mean difference = 1196 kJ 95% CI: 242, 2149) than at home. Most episodes were seated at tables (27%) or sofas (26%), but eating standing (19%) or at desks (18%) were common. Social interaction was evident for 45% of episodes and media screens were viewed during 55% of episodes. Meals at home watching television were 3.1 minutes longer (95% CI: -0.6 to 6.7) and higher in energy intake than when no screen was viewed (543 kJ 95% CI: -32 to 1120). The environmental and social context that surrounds eating and dietary behaviours can be assessed using wearable camera images.

Do physical activity and dietary smartphone applications incorporate evidence-based behaviour change techniques?

BACKGROUND: There has been a recent proliferation in the development of smartphone applications (apps) aimed at modifying various health behaviours. While interventions that incorporate behaviour change techniques (BCTs) have been associated with greater effectiveness, it is not clear to what extent smartphone apps incorporate such techniques. The purpose of this study was to investigate the presence of BCTs in physical activity and dietary apps and determine how reliably the taxonomy checklist can be used to identify BCTs in smartphone apps. METHODS: The top-20 paid and top-20 free physical activity and/or dietary behaviour apps from the New Zealand Apple App Store Health & Fitness category were downloaded to an iPhone. Four independent raters user-tested and coded each app for the presence/absence of BCTs using the taxonomy of behaviour change techniques (26 BCTs in total). The number of BCTs included in the 40 apps was calculated. Krippendorff's alpha was used to evaluate interrater reliability for each of the 26 BCTs. RESULTS: Apps included an average of 8.1 (range 2-18) techniques, the number being slightly higher for paid (M = 9.7, range 2-18) than free apps (M = 6.6, range 3-14). The most frequently included BCTs were "provide instruction" (83% of the apps), "set graded tasks" (70%), and "prompt self-monitoring" (60%). Techniques such as "teach to use prompts/cues", "agree on behavioural contract", "relapse prevention" and "time management" were not present in the apps reviewed. Interrater reliability coefficients ranged from 0.1 to 0.9 (Mean 0.6, SD = 0.2). CONCLUSIONS: Presence of BCTs varied by app type and price; however, BCTs associated with increased intervention effectiveness were in general more common in paid apps. The taxonomy checklist can be used by independent raters to reliably identify BCTs in physical activity and dietary behaviour smartphone apps.

Achieving the WHO sodium target: estimation of reductions required in the sodium content of packaged foods and other sources of dietary sodium.

BACKGROUND: Excess sodium intake is one of the top 2 dietary risk factors contributing to the global burden of disease. As such, many countries are now developing national sodium reduction strategies, a key component of which is a sodium reduction model that includes sodium targets for packaged foods and other sources of dietary sodium. OBJECTIVE: We sought to develop a sodium reduction model to determine the reductions required in the sodium content of packaged foods and other dietary sources of sodium to reduce adult population salt intake by ∼30% toward the optimal WHO target of 5 g/d. DESIGN: Nationally representative household food-purchasing data for New Zealand were linked with branded food composition information to determine the mean contribution of major packaged food categories to total population sodium consumption. Discretionary salt use and the contribution of sodium from fresh foods and foods consumed away from the home were estimated with the use of national nutrition survey data. Reductions required in the sodium content of packaged foods and other dietary sources of sodium to achieve a 30% reduction in dietary sodium intakes were estimated. RESULTS: A 36% reduction (1.6 g salt or 628 mg Na) in the sodium content of packaged foods in conjunction with a 40% reduction in discretionary salt use and the sodium content of foods consumed away from the home would reduce total population salt intake in New Zealand by 35% (from 8.4 to 5.5 g/d) and thus meet the WHO 2025 30% relative reduction target. Key reductions required include a decrease of 21% in the sodium content of white bread, 27% for hard cheese, 42% for sausages, and 54% for ready-to-eat breakfast cereals. CONCLUSIONS: Achieving the WHO sodium target in New Zealand will take considerable efforts by both food manufacturers and consumers and will likely require a national government-led sodium reduction strategy.