Behavior Change Interventions to Address Unhealthy Food Consumption: A Scoping Review

"A landscape of the BCI [behaviour change intervention] evidence on unhealthy food consumption is needed to adapt and develop best approaches to address this growing public health and nutrition challenge."

Low- and middle-income countries (LMICs) not only have high burdens of malnutrition but are experiencing a shift away from traditional diets toward energy-dense, nutrient-poor diets, and processed and ultraprocessed foods (high in saturated fats, salt, and sugar). Addressing unhealthy food consumption is distinct from promoting healthy food choice alone in that it requires deterring negative behaviours (often easy, convenient, and appealing) and promoting adoption of positive ones (which may be less tasty or satisfactory). Behaviour change strategies are used to discourage unhealthy food consumption and promote healthy food choices employing techniques such as nutrition education, goal setting, self-monitoring, and provision of feedback and support. This scoping review examines the existing evidence on behaviour change interventions (BCIs) to address unhealthy food consumption.

For the scoping review, unhealthy foods were operationally defined as specific foods/beverages, such as sugar-sweetened beverages (SSBs), sweets, processed meat, refined grains, deep-fried foods, added salt, and added sugar, and nutrients, such as saturated and trans-fat and cholesterol. Diets characterised by high levels of these foods and low in whole grains, fruit, and vegetables are considered unhealthy.

Through a systematic search of 3 databases conducted in December 2022, 2,730 records were retrieved, and 145 studies met the eligibility criteria for review. Most studies were randomised controlled trials (n = 93, 64.1%); 48 studies (33.1%) used quasi-experimental designs, and 4 studies (2.8%) used mixed methods. Only 19% of the studies (n=28) were from LMICs. The key priority group for most BCIs was adults 20 years or older (n=79). Interventions were conducted across 7 types of settings: schools (n=52), digital (n=30), community (n=28), home (n=14), health facility (n=12), worksite (n=6), and market (n=3).

There were 4 mutually inclusive intervention types. Most involved information, education, and communication (IEC) (n=141), such as 105 interventions that provided individual or group counseling, 65 that provided messages or information, and 8 that used mass media. Other interventions were food/beverage substitution (n=10), interactive games (n=7), and labeling/warnings at point of purchase (n=3). Drivers of food choice behaviours - e.g., knowledge, attitudes, and beliefs; motivation and expectancies; and self-efficacy - were reported in 43% of studies. The fact that less than half of the published literature reported on intermediary drivers of unhealthy food choices and consumption behaviour limits the understanding of how impacts on behaviour change were/were not achieved.

Mixed results were observed for reported impacts of BCIs on unhealthy food consumption outcomes. More than half of the studies (among those who measured these outcomes) reported impacts in reducing the consumption of saturated fat (76%), added table salt (59%), SSBs (58%), and packaged salty snacks/fast food (54%). Null impacts were reported for most studies targeting processed meat (73%) and sweets (54%). For the 3 most common outcomes (SSBs n = 74, packaged snacks n = 61, and sweets n = 43), higher proportion of interventions that were designed to reach adults reported impacts compared with those reaching out to young children or older children/adolescents. Potential reasons why interventions geared toward adults may have been more successful include greater cognitive ability, risk perceptions, motivation to change behaviours, and self-efficacy as compared with children.

In addition, more studies that applied counseling and multiple IEC component interventions (counseling, information, and/or mass media) reported positive impacts compared with those providing information alone. Approximately 60%-80% of multicomponent IEC interventions reported impacts on consumption of SSBs, packaged salty snacks and fast food, and sweets, compared with interventions with information only.

Interpretation of the findings was complicated by the lack of comparability in interventions, evaluation designs, outcome measures of unhealthy food consumption, duration of interventions, and study contexts.

The researchers suggest that future studies should invest in critical yet under-represented regions, examine behavioural determinants of unhealthy food consumption and the sustainability of behaviour change, and conduct further analysis of effectiveness from experimental studies.