Study of Purchasing Decisions and Food Consumption: Chile

Do Taxes on Unhealthy Foods and Subsidies on Healthy Foods Work in Chile ?: Study of Purchasing Decisions and Food Consumption

Objective: To evaluate the effectiveness of taxes on unhealthy foods and subsidies for healthy foods in modifying the purchasing and consumption behavior of people in the Metropolitan Region, Chile.

Research hypothesis:

1. The application of a tax that increases the price of "High in" foods by 20% will reduce the purchase and consumption of these foods by 24%.
2. The application of a subsidy that reduces the price of fruits and vegetables by 20% will increase the purchase and consumption of these foods by 17%.
3. People of lower socioeconomic status are more sensitive to price changes than people of higher socioeconomic status.

Methodological design. The research proposal proposes an experimental design that will select the participants from a panel composed of people over 18 years of age, men and women, and of all socioeconomic levels. The methodological design considers a random assignment of the people eligible for the study into 3 groups:

1. First group of intervention (GI1): people who will make their purchases with taxes on food and beverages "High in";
2. Second intervention group (GI2): people who will make their purchases with subsidies for fruits and vegetables;

4. Control group (CG) that will make the purchases with the market prices or currently applied by the supermarkets or purchase scenarios.

Methodology. Participants will make a monthly simulated purchase through a simulated supermarket system with products similar to those found in real supermarkets, including "High in" products and fruits and vegetables. Different prices will be applied to each group depending on the type of food. With the data of simulated purchases, a variation of the demand and by socioeconomic subgroup will be calculated. The results will be compared with the control group.

Expected results. GI1 participants are expected to modify their purchase intention with the "High in" food tax, decreasing the purchase of these products in their simulated purchases, compared to CG participants who will make their simulated purchases without taxes. Likewise, IG2 participants are expected to modify their purchase intention with the fruit and vegetable subsidy, increasing the purchase of these foods, compared to CG participants. Finally, it is assumed that the reduction in simulated purchases of "High in" foods and the increase in simulated purchases of fruits and vegetables vary according to socioeconomic level.

Study Overview

• Status: Unknown
• Conditions: Evaluate the Effectiveness of Taxes on Unhealthy; Evaluate the Effectiveness Subsidies for Healthy Foods
• Intervention / Treatment: Behavioral: Taxes; Behavioral: Subsidies; Behavioral: Control

• Study Type: Interventional
• Enrollment (Anticipated): 360
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Chile
  • Región Metropolitana
    • Santiago, Región Metropolitana, Chile
      • Recruiting
      • Carolina Gamboa Vidal
      • Contact: Carolina G Vidal; Phone Number: 223281749 223281749; Email: carolina.vidal@umayor.cl
      • Contact: Patrica M Caro; Phone Number: 223281749 223281749; Email: patricia.caro@umayor.cl
      • Sub-Investigator: Patricia CARO
      • Sub-Investigator: Lorena Hoffmeister
      • Principal Investigator: Carolina Vidal

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Over 18 years of age.
• Person responsible for household purchases.
• Living in a household with one or more boys or girls between 2-14 years of age

Exclusion Criteria:

• That in the home there are no dietary restrictions that prevent the development of this research such as eating disorders, food allergies

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: tax on purchases; exposed to high-price purchases of "high in" foods, including sugary drinks.	Behavioral: Taxes; a "High in" food tax will be applied to study changes in purchasing and consumption behavior of participants in this group. The tax will correspond to a 20% increase over the market price, that is, a tax that reaches the levels recommended by the WHO.
Experimental: subsidies on purchases; exposed to purchases with prices that consider subsidies in fruits and vegetables.	Behavioral: Subsidies; A subsidy will be applied to fruits and vegetables that means a reduction of 20% in their price, to study the changes in purchasing behavior and of the participants of said group.
Placebo Comparator: Control; It will not be subjected to any intervention and therefore will buy with current or market prices.	Behavioral: Control; Average or current food prices will apply. Based on the average of the values reported by three supermarkets

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
healthiness of the total shopping	percent of total unit food items defined as healthy	one measurement per participant (requested to purchase food for 15 days)

Collaborators and Investigators

• Sponsor: Universidad Mayor
• Collaborators: Sociedad Chilena de Pediatría
• Investigators: Principal Investigator: Carolina G Vidal, Escuela de Salud Pública Universidad Mayor, Chile

Publications and helpful links

General Publications

• Waterlander WE, Steenhuis IH, de Boer MR, Schuit AJ, Seidell JC. Introducing taxes, subsidies or both: the effects of various food pricing strategies in a web-based supermarket randomized trial. Prev Med. 2012 May;54(5):323-30. doi: 10.1016/j.ypmed.2012.02.009. Epub 2012 Feb 23.
• Waterlander WE, Steenhuis IH, de Boer MR, Schuit AJ, Seidell JC. The effects of a 25% discount on fruits and vegetables: results of a randomized trial in a three-dimensional web-based supermarket. Int J Behav Nutr Phys Act. 2012 Feb 8;9:11. doi: 10.1186/1479-5868-9-11.

Study record dates

Study Major Dates

• Study Start (Actual): November 5, 2020
• Primary Completion (Anticipated): January 5, 2021
• Study Completion (Anticipated): January 13, 2021

Study Registration Dates

• First Submitted: November 24, 2020
• First Submitted That Met QC Criteria: December 2, 2020
• First Posted (Actual): December 4, 2020

Study Record Updates

• Last Update Posted (Actual): December 4, 2020
• Last Update Submitted That Met QC Criteria: December 2, 2020
• Last Verified: December 1, 2020

More Information

Terms related to this study

• Keywords: Nutrition policy; taxes; Health policy; subsidies
• Other Study ID Numbers: FONISSA17I0121

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

IPD Plan Description

It has not been decided yet. However, the project corresponds to a project awarded from public funds. So Fonis will also safeguard the information.

The results will be published and any information on the project may be requested in a general email from the School of Public Health of the Universidad Mayor (salud.publica@umayor.cl)

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No