# Testing combinations of population interventions to encourage healthy eating

> **NIH NIH R01** · UNIVERSITY OF CALIFORNIA, SAN FRANCISCO · 2021 · $754,951

## Abstract

ABSTRACT
Population-level interventions to encourage healthy eating—which involve changing food environments or
purchasing conditions—have been extensively discussed for the prevention of obesity and type 2 diabetes.
Preliminary data suggest that population interventions introduced in isolation (such as an SSB tax) can have a
modest effect, but multi-faceted interventions should be introduced in combination, to produce large and
meaningful improvements in healthy eating. Studying combinations of population interventions is difficult, as
such interventions are rare. We propose to rigorously assess a rare set of nested natural experiments in the
two largest, most diverse urban settings in California (CA): Los Angeles and the San Francisco Bay Area. We
will identify the complementarities among major population-level interventions to encourage healthy eating. In
Aim 1, we will conduct a prospective evaluation of a population-wide SSB tax in both tax-affected and matched
unaffected CA counties. We will identify changes to both beverage and food consumption and purchasing, food
substitution patterns, spillover to neighboring areas, effects of marketing, and any regressive economic effects
for low-income populations. The longer-term follow-up period enabled by our design will test the hypothesis
that a SSB tax produces sustained declines in SSB consumption rather than merely short-term effects followed
by a return to pre-tax consumption. Uniquely, we will then test complementarity between the tax and other
interventions in Aims 2 and 3. In Aim 2, we will examine the complementarity of the SSB tax with a fruit and
vegetable voucher program. Some SSB tax-affected and distant tax-unaffected counties have introduced fresh
fruit and vegetable purchasing vouchers, which enable low-income families facing food insecurity to purchase
fruits and vegetables at major supermarkets and corner stores in the area, not just at farmer’s markets. We will
test the hypothesis, supported by our preliminary data, that pairing the purchasing penalty of an SSB tax with a
purchasing incentive of a fruit and vegetable voucher improves upon the modest effect of either intervention
alone. In Aim 3, we will identify the complementarity between the SSB tax and a workplace SSB purchasing
ban, implemented in some workplaces but not others during tax-affected and -unaffected periods. We will test
the hypothesis, consistent with our preliminary data, that workplace bans disproportionately reduce SSB
consumption in the lowest-income employees, neutralizing the economically-regressive effect of a SSB tax.
We will evaluate these interventions using innovative methods that advance the study of natural experiments in
obesity and diabetes prevention. Specifically, we will use a synthetic control statistical method, which adjusts
for unmeasured confounders such as differences in culture among the intervention and control areas. Second,
we will input our results into validated computer simulatio...

## Key facts

- **NIH application ID:** 10159248
- **Project number:** 5R01DK116852-04
- **Recipient organization:** UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
- **Principal Investigator:** DEAN SCHILLINGER
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $754,951
- **Award type:** 5
- **Project period:** 2018-06-20 → 2023-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10159248

## Citation

> US National Institutes of Health, RePORTER application 10159248, Testing combinations of population interventions to encourage healthy eating (5R01DK116852-04). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10159248. Licensed CC0.

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