Effect of Taxes and Subsides on Food Purchases in Mothers
Conditions
Brief summary
The goal of the proposed study is to apply experimental economics in an online grocery store shopping model to examine the effects of pricing on hypothetical food purchases
Detailed description
Participants will be lean and overweight primary grocery shoppers aged 18 years and older. Participants will be considered lean if their body mass index (BMI = kg/m2) is less than 29.9, overweight if their BMI is greater than or equal to 30.12 To meet eligibility for the study, participants must be the guardian of a child at least 2 years or older, do the primary grocery shopping for the family, they must also report being weekly household grocery shoppers, and purchase the majority of their household's groceries once a week.
Interventions
None listed
Sponsors
State University of New York at Buffalo
Study design
Time perspective
CROSS_SECTIONAL
Eligibility
Sex/Gender
FEMALE
Age
18 Years to 65 Years
Healthy volunteers
Yes
Inclusion criteria
18 or older primary shopper in the household, at least one child over 2 years of age
Exclusion criteria
eating disorders, not liking study foods
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in Energy Purchased as a Result of Taxes. | Study Completion | Change in total calories as a result of taxes of 12.5% and 25%. |
| Change in Energy Purchased as a Result of Subsidies | Study Completion | Change in total calories as a result of subsidies of 12.5% and 25%. |
Countries
United States
Participant flow
Recruitment details
Recruitment in the Western New York Area targeted primary household grocery shoppers through the local community during 2011-2013.
Pre-assignment details
Interested eligible participants were screened and offered to start the study.
Participants by arm
| Arm | Count |
|---|---|
| Lean Participants Participants whose baseline BMI is less than 25.
All participants completed a baseline session where behavioral measures of delay discounting, relative reinforcing value and relative reinforcing efficacy were measured. Participants then completed five shopping sessions under various price conditions. Age and Body Mass Index were measured at the end of the six session study; therefore, 5 participants were lost to follow up and no age or body mass index are reported for these participants. | 102 |
| Overweight/Obese Participants Participants whose baseline BMI is greater than or equal to 25.
All participants completed a baseline session where behavioral measures of delay discounting, relative reinforcing value and relative reinforcing efficacy were measured. Participants then completed five shopping sessions under various price conditions. Age and Body Mass Index were measured at the end of the six session study; therefore, 5 participants were lost to follow up and no age or body mass index are reported for these participants. | 110 |
| Total | 212 |
Withdrawals & dropouts
| Period | Reason | FG000 |
|---|---|---|
| Overall Study | Lost to Follow-up | 5 |
Baseline characteristics
| Characteristic | Total | Overweight/Obese Participants | Lean Participants |
|---|---|---|---|
| Age, Continuous | 42.7 years STANDARD_DEVIATION 7.4 | 42.5 years STANDARD_DEVIATION 7.4 | 43.0 years STANDARD_DEVIATION 7.5 |
| Body Mass Index | 27.6 kg/m^2 STANDARD_DEVIATION 7.2 | 22.2 kg/m^2 STANDARD_DEVIATION 2 | 32.6 kg/m^2 STANDARD_DEVIATION 6.6 |
| Delay Discounting $100 reward (DD 100) | 0.7 indifference proportion*delay proportion STANDARD_DEVIATION 0.3 | 0.7 indifference proportion*delay proportion STANDARD_DEVIATION 0.3 | 0.7 indifference proportion*delay proportion STANDARD_DEVIATION 0.2 |
| Delay Discounting $10 reward (DD 10) | 0.6 indifference proportion*delay proportion STANDARD_DEVIATION 0.3 | 0.6 indifference proportion*delay proportion STANDARD_DEVIATION 0.3 | 0.7 indifference proportion*delay proportion STANDARD_DEVIATION 0.3 |
| Ethnicity (NIH/OMB) Hispanic or Latino | 2 Participants | 0 Participants | 2 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 210 Participants | 110 Participants | 100 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| Gender Female | 204 Participants | 105 Participants | 99 Participants |
| Gender Male | 8 Participants | 5 Participants | 3 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 1 Participants | 1 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 8 Participants | 3 Participants | 5 Participants |
| Race (NIH/OMB) Black or African American | 36 Participants | 22 Participants | 14 Participants |
| Race (NIH/OMB) More than one race | 1 Participants | 0 Participants | 1 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 4 Participants | 1 Participants | 3 Participants |
| Race (NIH/OMB) White | 162 Participants | 83 Participants | 79 Participants |
| Relative Reinforcing Value High Energy Dense Foods (RRV HED) | 14.7 Highest Response schedule completed STANDARD_DEVIATION 38.8 | 15.9 Highest Response schedule completed STANDARD_DEVIATION 25.1 | 13.8 Highest Response schedule completed STANDARD_DEVIATION 50.4 |
| Relative Reinforcing Value Low Energy Dense Foods (RRV LED) | 25.2 Highest response schedule completed STANDARD_DEVIATION 32.9 | 23.9 Highest response schedule completed STANDARD_DEVIATION 30.4 | 26.0 Highest response schedule completed STANDARD_DEVIATION 34.7 |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | — / — |
| other Total, other adverse events | 0 / 217 |
| serious Total, serious adverse events | 0 / 217 |
Outcome results
Primary
Change in Energy Purchased as a Result of Subsidies
Change in total calories as a result of subsidies of 12.5% and 25%.
Time frame: Study Completion
Population: Data is reported for 199 participants. Out of 217 participants who started the study, 5 participants were lost to follow up, 1 participant shopped in the same store twice, 2 participants had conditions that would affect shopping, 2 participants did not report minority status and 8 male participants were excluded due to the small sample number.
| Arm | Measure | Group | Value (LEAST_SQUARES_MEAN) | Dispersion |
|---|---|---|---|---|
| Online Grocery | Change in Energy Purchased as a Result of Subsidies | Calories Purchased in the Subsidy 25 Condition | 10189.55 Total Calories Purchased | Standard Error 300.85 |
| Online Grocery | Change in Energy Purchased as a Result of Subsidies | Calories Purchased in the Subsidy 12.5 Condition | 10369.12 Total Calories Purchased | Standard Error 283.95 |
| Online Grocery | Change in Energy Purchased as a Result of Subsidies | Calories Purchased in the Regular Condition | 10548.69 Total Calories Purchased | Standard Error 316.69 |
| Lean Participants | Change in Energy Purchased as a Result of Subsidies | Calories Purchased in the Subsidy 25 Condition | 11036.01 Total Calories Purchased | Standard Error 519.23 |
| Lean Participants | Change in Energy Purchased as a Result of Subsidies | Calories Purchased in the Regular Condition | 10507.63 Total Calories Purchased | Standard Error 437.92 |
| Lean Participants | Change in Energy Purchased as a Result of Subsidies | Calories Purchased in the Subsidy 12.5 Condition | 10176.01 Total Calories Purchased | Standard Error 442.21 |
| Overweight/Obese Participants | Change in Energy Purchased as a Result of Subsidies | Calories Purchased in the Subsidy 25 Condition | 10509.31 Total Calories Purchased | Standard Error 426.99 |
| Overweight/Obese Participants | Change in Energy Purchased as a Result of Subsidies | Calories Purchased in the Subsidy 12.5 Condition | 9704.67 Total Calories Purchased | Standard Error 405.05 |
| Overweight/Obese Participants | Change in Energy Purchased as a Result of Subsidies | Calories Purchased in the Regular Condition | 10311.12 Total Calories Purchased | Standard Error 456.04 |
Primary
Change in Energy Purchased as a Result of Taxes.
Change in total calories as a result of taxes of 12.5% and 25%.
Time frame: Study Completion
Population: Data is reported for 199 participants. Out of 217 participants who started the study, 5 participants were lost to follow up, 1 participant shopped in the same store twice, 2 participants had conditions that would affect shopping, 2 participants did not report minority status and 8 male participants were excluded due to the small sample number.
| Arm | Measure | Group | Value (LEAST_SQUARES_MEAN) | Dispersion |
|---|---|---|---|---|
| Online Grocery | Change in Energy Purchased as a Result of Taxes. | Calories Purchased in the Tax 12.5 Condition | 10401.13 Total Calories Purchased | Standard Error 292.12 |
| Online Grocery | Change in Energy Purchased as a Result of Taxes. | Calories Purchased in the Regular Condition | 10622.09 Total Calories Purchased | Standard Error 329.04 |
| Online Grocery | Change in Energy Purchased as a Result of Taxes. | Calories Purchased in the Tax 25 Condition | 10180.17 Total Calories Purchased | Standard Error 304.13 |
| Lean Participants | Change in Energy Purchased as a Result of Taxes. | Calories Purchased in the Tax 12.5 Condition | 10512.95 Total Calories Purchased | Standard Error 523.1 |
| Lean Participants | Change in Energy Purchased as a Result of Taxes. | Calories Purchased in the Regular Condition | 10507.62 Total Calories Purchased | Standard Error 427.92 |
| Lean Participants | Change in Energy Purchased as a Result of Taxes. | Calories Purchased in the Tax 25 Condition | 10471.42 Total Calories Purchased | Standard Error 464.73 |
| Overweight/Obese Participants | Change in Energy Purchased as a Result of Taxes. | Calories Purchased in the Regular Condition | 10311.12 Total Calories Purchased | Standard Error 456.04 |
| Overweight/Obese Participants | Change in Energy Purchased as a Result of Taxes. | Calories Purchased in the Tax 25 Condition | 10184.04 Total Calories Purchased | Standard Error 436.78 |
| Overweight/Obese Participants | Change in Energy Purchased as a Result of Taxes. | Calories Purchased in the Tax 12.5 Condition | 9733.12 Total Calories Purchased | Standard Error 385.34 |