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Table 1 Description of studies included in the analysis 

From: Is altering the availability of healthier vs. less-healthy options effective across socioeconomic groups? A mega-analysis

Paper (& study)

Setting

Sample

Intervention

Findings

Odds ratio (OR) (95%CIs)

Notes

N (obs)

Recruitment criteria

Availability typea

Availability conditions

Food target(s)

Impact of availability on healthier option selection

Differential impact of availability by SEP

Pechey & Marteau (2018) [16]

Online; Images of food options

1509 (1509)

UK adults

Quotas set by gender, age and occupational status

Absolute & Relative; Range changed

(E) two healthier, two less healthy foods,

(MH) six healthier, two less healthy foods,

(MLH) two healthier, six less healthy foods

Snacks

Ref. group E:

MH: 2.0 (1.6, 2.6)

MLH: 0.23 (0.17, 0.32)

Main effects (higher education [ref: 1–4 GCSEs]):

5 + GCSEs: 1.7 (n.s., 0.8, 3.8);

2 + A levels: 1.4 (n.s, 0.6, 3.5);

Degree: 1.8 (n.s., 0.9, 3.6)

Interactions (MH [ref: E]):

5 + GCSEs: 0.6 (n.s., 0.2, 1.8);

2 + A levels: 1.0 (n.s., 0.3, 3.2);

Degree: 0.6 (n.s., 0.3, 1.6)

Interactions (MLH [ref: E]):

5 + GCSEs: 0.4 (n.s., 0.1, 1.7);

2 + A levels: 0.2 (n.s., 0.0, 1.5);

Degree: 0.8 (n.s., 0.3, 2.3)

Other manipulations: cognitive load (high; low)

Pechey, Clarke, Pechey, Ventsel, Hollands, & Marteau (2021) [25]: Study 1

Online; Images of food options

2340

(18,720)

UK adults

Quotas set by gender, age and education

Relative; Range kept the same

(E) 50% healthier;

(MH) 75% healthier;

(MLH) 25% healthier

[number of options varied by trial]

Snacks; Drinks

For fuller shelves condition onlyb; Ref. group E:

MH: 1.14 (1.01, 1.28)

MLH: 0.95 (n.s., 0.84, 1.07)

Not assessed

Other manipulations: Display layout (emptierb; fuller); Manipulation-level (product; category)

Participants were explicitly asked about popularity pre-selection

Pechey, Clarke, Pechey, Ventsel, Hollands, & Marteau (2021) [25]: Study 2

Laboratory; Real food options

139

(139)

UK adults

Quotas set by gender, age and education

Relative; Range kept the same

(MH) 6/9 healthier & 3/9 less-healthy;

(MLH) 3/9 healthier & 6/9 less-healthy

Snacks

For fuller shelves condition onlyb; Ref. group MLH:

MH: 3.3 (n.s., 0.99, 10.9)

Not assessed

Other manipulations Display layout (emptierb; fuller)

Pechey, Sexton, Codling & Marteau (2021) [17]

Laboratory; Real food options

417

(417)

UK adults

Quotas set by gender, age and education

Absolute & Relative; Range changed

(E) two healthier, two less healthy foods,

(MH) six healthier, two less healthy foods,

(MLH) two healthier, six less healthy foods

Snacks

Ref. group E:

MH: 2.5 (1.5, 4.1)

MLH: 0.34 (0.20, 0.60)

Main effect (higher educationc [ref: lower]): 0.54 (n.s., 0.26, 1.12)

Interaction (MH [ref: E]): 2.50 (n.s., 0.91, 6.83)

Interaction (MLH [ref: E]): 4.04 (1.31, 12.40)

None

Pechey, Hollands & Marteau (2022) [18]: Study 1

Online; Images of food options

1976

(7904)

UK adults

Quotas set by gender, age and education

Exclusions: Vegetarians

Relative; Range changed

(MH) 3 healthier; 1 less-healthy;

(MLH) 3 less-healthy; 1 healthier

Snacks; Meals

Ref. group MLH:

MH: 8.9 (7.9, 10.1)

Main effect (higher educationc [ref: lower]): 1.1 (n.s., 0.9, 1.3)

Interaction: 1.0 (n.s., 0.8, 1.2)

None

Pechey, Hollands & Marteau (2022) [18]: Study 2

Online; Images of food options

1078

(2156)

UK adults

Quotas set by gender, age and education

Exclusions: Vegetarians

Relative; Range changed

(MH) 3 healthier; 1 less-healthy;

(MLH) 3 less-healthy; 1 healthier

Meals

Ref. group MLH:

MH: 9.7 (7.0, 13.5)

Main effect (higher educationc [ref: lower]): 1.4 (n.s., 0.9, 2.1)

Interaction: 1.3; (n.s., 0.8, 2.1)

Greater differences by preference between healthier vs. less-healthy than Study 1

  1. Snacks: Lower-energy (under 100 kcal per pack) vs. higher-energy (over 200 kcal per pack); Drinks: Lower sugar (less than 2.5 g of sugar per 100 ml); higher sugar (2.5 g or more of sugar per 100 ml); Meals: Lower-energy (under 500 kcal per meal); higher-energy (over 500 kcal per meal)
  2. Quotas by age and gender were designed to be representative of the UK population; quotas by SEP recruited equal numbers of higher vs. lower SEP participants
  3. E Equal number of healthier vs. less-healthy options, MH More healthier than less healthy options, MLH More less-healthy than healthy options
  4. aAvailability types as defined in a conceptual review of availability interventions [12]; (i) Absolute Availability (changing the overall number of options, while keeping the proportions comprised by any subsets of options constant); (ii) Relative Availability (changing the proportion comprised by a subset of options, yet keeping the overall number of options constant); (iii) Absolute and Relative Availability (changing both the overall number of options and the proportions comprised by subsets of options). This was determined for the key comparisons made within the papers, i.e. for Pechey & Marteau (2018) and Pechey, Sexton, Codling & Marteau (2021), this was the comparison between the ‘Equal’ condition and the other availability conditions
  5. b“Emptier” trials (layouts designed to reverse the effect of availability by implying previous participants had more frequently selected options that were less available on shelves or trays) were excluded from the mega-analysis; For Pechey, Clarke, Pechey, Ventsel, Hollands, & Marteau (2021) [25]: Study 1: 9306 trials were ‘fuller’ trials; Study 2, 68 participants completed ‘fuller’ trials
  6. cIn Pechey, Hollands & Marteau (2022) higher education equated to 2 or more A levels; in Pechey, Sexton, Codling & Marteau (2021) [17], higher education equated to degree level or higher
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International Journal of Behavioral Nutrition and Physical Activity

ISSN: 1479-5868

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