Do financial constraint and perceived stress modify the effects of food tax schemes on food purchases: moderation analyses in a virtual supermarket experiment

• Published in: Public health nutrition 2024-01, Vol.27 (1), p.1-e38, Article e38
• Main Authors: Djojosoeparto, Sanne K, Poelman, Maartje P, Eykelenboom, Michelle, Beenackers, Mariëlle A, Steenhuis, Ingrid HM, van Stralen, Maartje M, Olthof, Margreet R, Renders, Carry M, van Lenthe, Frank J, Kamphuis, Carlijn BM
• Format: Article
• Language: English
• Subjects: Adults; Behavior; Beverages; Chronic illnesses; Constraints; Diet; Financial constraint; Food; Food products; Food-related taxes; Fruits; Health care; Healthiness food purchases; Hypotheses; Interventions; Nutrients; Nutrition research; Perceived stress; Price increases; Regression analysis; Regression models; Research Paper; Socioeconomic factors; Soft drinks; Subgroups; Sugar; Supermarkets; Tax rates; Taxation; Taxes; Vegetable juices
• ISSN: 1368-9800; 1475-2727
• DOI: 10.1017/S1368980024000077

To investigate whether financial constraint and perceived stress modify the effects of food-related taxes on the healthiness of food purchases. Moderation analyses were conducted with data from a trial where participants were randomly exposed to: a control condition with regular food prices, an SSB tax condition with a two-tiered levy on the sugar content in SSBs (5-8 g/100ml: €0.21/l and 8g/100 ml: €0.28/l) or a nutrient profiling tax condition where products with Nutri-Score D or E were taxed at a 20 percent level. Outcome measures were: overall healthiness of food purchases (%), energy content (kcal) and SSB purchases (litres). Effect modification was analyzed by adding interaction terms between conditions and self-reported financial constraint or perceived stress in regression models. Outcomes for each combination of condition and level of effect modifier were visualized. Virtual supermarket. Dutch adults (n = 386). Financial constraint or perceived stress did not significantly modify the effects of food-related taxes on the outcomes. Descriptive analyses suggest that in the control condition, the overall healthiness of food purchases was lowest and SSB purchases were highest among those with moderate/high levels of financial constraint. Compared to the control condition, in a nutrient profiling tax condition the overall healthiness of food purchases was higher and SSB purchases were lower, especially among those with moderate/high levels of financial constraint. Such patterns were not observed for perceived stress. Further studies with larger samples are recommended to assess whether food-related taxes differentially affect food purchases of subgroups.