Table 2 Study characteristics and main findings of included studies categorized by TIPPME intervention type
Author | Year | Country | Nudge description | Study design | Study size | Intervention duration | Setting | SEP | Study outcome(s) | Outcome assessment | Main finding(s) | Quality assessment |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Information nudges (symbols) | ||||||||||||
 Cawley et al. [19] | 2015 | USA | Supermarket items were assigned with stars indicating their relative healthiness | Pre-post | 168 supermarkets | >  1 year | Supermarket | N/A | Purchases healthy items (any stars); Purchases of unhealthy items (no stars) | Point of sale system | 1a. Purchases of healthy items were not affected 1b. Purchases of unhealthy items decreaseda | Moderate |
 Dubbert et al. [20] | 1984 | USA | Labels indicating low-calorie choices were placed besides serving location | Pre-post | 6970 customers | >  1 week & ≤ 1 month | Cafeteria | N/A | Purchases of vegetables; Purchases of salad; Purchases of entrees; Caloric content of meal purchased | Point of sale system and observer reported | 2a. Increased vegetable purchasesa 2b. Increased salad purchasesa 2c. Entrée purchases not affected 2d. Caloric content of meals purchased not affected | Weak |
 Elbel et al. [21] | 2013 | USA | Unhealthy items were assigned a tag stating ‘less healthy’ | Pre-post | 3680 purchases | >  1 week & ≤ 1 month | Small food store | Store catered to low-income, minority and immigrant population | Purchases of healthy items; Caloric content of purchases | Point of sale system | 3a. Probability of purchasing healthy items increaseda 3b. Caloric content of items purchased decreaseda | Strong |
 Eldridge et al. [22] | 1997 | USA | Menu boards indicated healthy items with a green check-mark | Pre-post | 7 cafeterias | 6 < months ≤12 | Cafeteria | N/A | Purchases of all targeted items | Point of sale system | 4. Purchases of targeted items were not affected | Moderate |
 Freedman et al. [23] | 2011 | USA | Healthy foods were identified with a promotional logo on shelf-tags | Pre-post | 1 small food store | 1 < month(s) ≤ 6 | Small food store | N/A | Purchases of all targeted items | Point of sale system | 5. Purchases of targeted items were not affected | Moderate |
 Hobin et al. [24] | 2017 | Canada | Supermarket items were assigned with stars indicating their relative healthiness | CT | 44 intervention supermarkets; 82 control supermarkets | 6 < months ≤12 | Supermarket | Supermarkets were located in area where 13.1% had no secondary school diploma | Purchases of healthy items; Caloric content of purchases | Point of sale system | 6a. Average mean star rating per product purchased increased, so healthy purchases increaseda 6b. Caloric content of purchases was not affected | Strong |
 Hoefkens et al. [25] | 2011 | Belgium | Healthy meal suggestions were assigned with stars (0–3 stars) | Pre-post | 224 customers | >  1 week & ≤ 1 month | Cafeteria | N/A | Meal choice (0–3 stars) and energy intake | Questionnaire | 7a. Meal choice was not affected; 7b. Energy intake was not affected | Weak |
 Johnson et al. [26] | 1990 | USA | Labels indicating low-calorie choices were placed besides serving location | Pre-post | 413 customers | >  1 week & ≤ 1 month | Cafeteria | N/A | Caloric content of purchases | Observer reported | 8. Caloric content of purchases was not affected | Weak |
 Lassen et al. [27] | 2014 | Norway | Healthy choices were labelled with the Keyhole symbol | CT | 270 customers | 6 < months ≤12 | Cafeteria | 59% employed as office and administrative personnel or as technical staff | Energy density of consumed foods | Digital photographic method | 9. Energy density decreaseda | Strong |
 Levin et al. [28] | 1996 | USA | Low-fat entrees were labelled with a heart-shaped symbol | CT | 2 cafeterias | 6 < months ≤12 | Cafeteria | N/A | Purchases of targeted items | Point of sale system | 10. Purchases of targeted items increaseda | Moderate |
 Sproul et al. [29] | 2003 | USA | Healthy entrees were labelled with a promotional logo, which additionally provided nutritional information | Pre-post | 1 cafeteria | 1 < month(s) ≤ 6 | Cafeteria | N/A | Purchases of targeted entrees | Point of sale system | 11. Purchases of targeted entrees were not affected | Moderate |
 Sutherland et al. [30] | 2010 | USA | Supermarket items were assigned with stars indicating their relative healthiness | Pre-post | 168 supermarkets | >  1 year | Supermarket | N/A | Purchases of star-labelled items | Point of sale system | 12. Purchases of star-labelled items increaseda | Moderate |
 Vyth et al. [31] | 2011 | The Netherlands | Healthy sandwiches, soups, and fresh fruit were identified with a promotional logo | RCT | 13 intervention cafeterias; 12 control cafeterias | >  1 week & ≤ 1 month | Cafeteria | N/A | Purchases of healthy sandwiches; Purchases of healthy soups; Purchases of fresh fruit | Point of sale system | 13a. Purchases of healthy sandwiches were not affected 13b. Purchases of healthy soups were not affected 13c. Fruit purchases increaseda | Moderate |
 Mazza et al. [32] | 2017 | USA | Emoticons highlighted healthy items | Pre-post | 1 cafeteria | 1 < month(s) ≤ 6 | Cafeteria | N/A | Purchases of healthy beverages Purchases of healthy chips | Point-of-sale system | 14a. Purchases of healthy chips were not affected 14b. Purchases of healthy beverages were not affected | Moderate |
 Steenhuis et al. [33] | 2004 | The Netherlands | In the labelling program, low-fat products were identified with a promotional logo. | RCT | 17 cafeterias were randomly assigned to either of 4 conditions (including control and labelling program) | 1 < month(s) ≤ 6 | Worksite cafeteria | 2% low educational level | Purchases of low-fat items (milk, butter, cheese, meat, desserts). | Point of sale system and questionnaire | 15a. Purchases of low-fat desserts increaseda 15b. Purchases of milk were not affected 15c. Purchases of butter were not affected 15d. Purchases of cheese were not affected 15e. Purchases of meat were not affected | Weak |
Information nudges (nutrition information) | ||||||||||||
 Cioffi et al. [34] | 2015 | USA | Nutrition labels were added to a selection of pre-packaged meals and snacks | Pre-post | 20 small food stores | 6 < months ≤12 | Small food store | N/A | Purchases of low calorie foods; Purchases of high calorie foods; Caloric content of purchases | Point of sale system | 1a. Purchases of low calorie foods increaseda 1b. Purchases of high calorie foods decreased 1c. Caloric content of items purchased decreaseda | Moderate |
 Hammond et al. [35] | 2015 | Canada | Calorie labels were added to all cafeteria menu boards and food stations | Pre-post | 159 customers | ≤ 1 week | University cafeteria | N/A | Caloric content of purchases; Calories consumed | Questionnaire | 2a. Caloric content of purchases decreaseda 2b. Calorie intake decreaseda | Weak |
 Milich et al. [36] | 1976 | USA | Foods were labelled with their caloric value | Pre-post | 450 customers | ≤ 1 week | Hospital cafeteria | N/A | Caloric content of purchases | Observer reported | 3. Caloric content of purchases decreased; (p = 0.06) | Weak |
 Vanderlee et al. [37] | 2014 | Canada | Energy, sodium and fat content were displayed on digital menu boards, as well as a health logo for healthier items | CT | 497 customers at intervention site; 506 customers at control site | 1 < month(s) ≤ 6 | Hospital cafeteria | 14% low educational level (high school or less) 15% low income (<$CAN 40000) | Calorie intake | Questionnaire | 4. Caloric intake decreaseda | Weak |
 Aron et al. [38] | 1995 | UK | Foods were provided with nutrition labels | CT | 65 intervention customers; 35 control customers | ≤ 1 week | University cafeteria | N/A | Calorie intake | Questionnaire | 5. Caloric intake increaseda | Weak |
 Chu et al. [39] | 2009 | USA | Simplified nutrition labels were posted at the point of selection for entrée dishes | Pre-post | 1 cafeteria | >  1 week & ≤ 1 month | University cafeteria | N/A | Caloric content of purchases | Point of sale system | 6. Caloric content of purchases was not affected | Moderate |
 Webb et al. [40] | 2011 | USA | Calorie information was posted on menu boards or was provided only on posters placed away from the point of decision. | CT | 1 experimental cafeteria; 1 control cafeteria | 1 < month(s) ≤ 6 | Hospital cafeteria | 13% low educational level (< eighth grade, some high school and high school graduate) | Purchases of healthy side dishes; Purchases of healthy snacks; Purchases of healthy entrees | Point of sale system | 7a. Purchases of sides dishes increaseda 7b. Purchases of snacks increaseda 7c. Purchases of entrees were not affected | Moderate |
 Chen et al. [41] | 2017 | Taiwan | Entrees and side dishes were labeled with traffic-light labels | Pre-post | 276 customers for first survey; 205 customers for second survey | 6 < months ≤12 | Worksite cafeteria | N/A | Choice for green-labelled food; Attempt to avoid red-labelled food | Questionnaire | 8a. Choice for green entrée increaseda; 8b. Attempt to avoid red-coloured items was not affected. | Moderate |
 Sonnenberg et al. [42] | 2013 | USA | Food and beverages were labelled red, yellow, or green on either the menu board, shelf, or directly on the packaging. | Pre-post | 389 customers | 1 < month(s) ≤ 6 | Hospital cafeteria | N/A | Purchases of green items Purchases of red items | Point of sale system | 9a. Healthy (green) item purchases were not affected 9b. Unhealthy (red) item purchases were not affected | Strong |
 Whitt et al. [43] | 2017 | USA | Items were labelled green (healthy), yellow (neutral) or red (unhealthy). | Pre-post | 1 small food store | 1 < month(s) ≤ 6 | Small food store | N/A | Purchases of green items Purchases of red items | Point of sale system | 10a. Purchases of healthy (green) items increaseda 10b. Purchases of unhealthy (red) items decreaseda | Moderate |
Information nudges (signage) | ||||||||||||
 Allan et al. [44] | 2015 | UK | Signs visually arranged snacks and drinks from least caloric to most caloric, with arrows indicating their location in store | RCT | > 20,000 purchases | 1 < month(s) ≤ 6 | Small food store | N/A | Purchases of high-calorie snacks Purchases high-calorie drinks | Point of sale system | 1a. Purchases of high calorie snacks decreaseda; 1b. Purchases of high calorie drinks were not affected. | Moderate |
 Buscher et al. [45], study 1 | 2001 | Canada | Signs with promotional prompts were located at the cafeteria entrance and in front of the targeted foods | Pre-post | 2280 students potentially exposed to the intervention | >  1 week & ≤ 1 month | University cafeteria | N/A | Purchases of vegetable basket Purchases of pretzels Purchases of yoghurt Purchases of fruit basket | Point of sale system and hand-counts | 2a. Vegetable basket purchases were not affected 2b. Pretzel purchases increaseda 2c. Yoghurt purchases increaseda 2d. Fruit basket purchases were not affected | Moderate |
 Buscher et al. [45], study 2 | 2001 | Canada | Signs with promotional prompts were located at the cafeteria entrance and in front of the targeted yoghurt | Pre-post | 2280 students potentially exposed to the intervention | >  1 week & ≤ 1 month | University cafeteria | N/A | Purchases of yoghurt | Point of sale system | 3. Yoghurt purchases increaseda | Moderate |
 Montuclard et al. [46] | 2017 | USA | A water sign was taped to the cafeterias soda dispensers and coffee dispensers | Pre-post | 357 students pre-intervention survey; 301 students post-intervention survey | 1 < month(s) ≤ 6 | University cafeteria | N/A | Choice for water | Questionnaire | 4. Choice for water increaseda | Moderate |
 Ogawa et al. [47] | 2011 | Japan | Health and nutrition information related to consumption of fruits and vegetables was displayed on posters near fruit/vegetable display and/or checkout counter | CT | 1 intervention supermarket; 1 control supermarket | 1 < month(s) ≤ 6 | Supermarket | N/A | Purchases of fruits Purchases of vegetables | Point of sale system | 5a. Vegetable purchases increaseda 5b. Fruit purchases were not affected. | Moderate |
 Policastro et al. [48] | 2017 | USA | Water consumption was promoted through signage promoting swapping soda for water | Pre-post | 2393 students covering 6730 transactions | ≤ 1 week | University cafeteria | N/A | Choice for water | Point of sale system | 6. Water purchases increaseda | Moderate |
 Scourboutakos et al. [49] | 2017 | Canada | Posters promoted water and fruit and vegetable consumption | Pre-post | 368 to 510 students per data collection day | 1 < month(s) ≤ 6 | University cafeteria | N/A | Purchases of water Purchases of fruits Purchases of vegetables | Observer reported | 7a. Purchases of water increaseda 7b. Purchases of fruit increaseda 7c. Purchases of vegetables increaseda | Weak |
 Mazza et al. [32] | 2018 | USA | A health message stating the % of daily calories contained in beverages, and required exercise to burn calories of chips | Pre-post | 1 cafeteria | >  1 week & ≤ 1 month | Hospital cafeteria | N/A | Purchases of healthy chips Purchases of healthy beverages | Point of sale system | 8a. Purchases of healthy chips were not affected 8b. Purchases of healthy beverages were not affected | Moderate |
 Mazza et al. [32] | 2018 | USA | A health message stating the % of daily calories contained in chips, and required exercise to burn calories of beverages | Pre-post | 1 cafeteria | >  1 week & ≤ 1 month | Hospital cafeteria | N/A | Purchases of healthy chips Purchases of healthy beverages | Point of sale system | 9a. Purchases of healthy chips increaseda 9b. Purchases of healthy beverages were not affected | Moderate |
 Payne et al. [50], study 1 | 2015 | USA | Messages on grocery carts stated the number of fruits and vegetable items customers of that particular store normally purchased | CT | 396,017 individual person transactions | >  1 week & ≤ 1 month | Supermarket | Supermarkets were located in area with 7% unemployment and 24% only high school education | Purchases of fruits and vegetables | Point-of-sale system | 10. Fruit and vegetable purchases increaseda | Strong |
 Payne et al. [50], study 2 | 2015 | USA | Messages on grocery carts stated the number of F&V items customers of that particular store normally purchased | Pre-post | 575,689 individual person transactions | >  1 week & ≤ 1 month | Supermarket | Supermarkets were located in area with 7% unemployment and 24% only high school education | Purchases of fruits and vegetables | Point-of-sale system | 11. Fruit and vegetable purchases increaseda | Strong |
 Salmon et al. [51] | 2015 | The Netherlands | The presence of a banner with was manipulated (absent/present, which stated that a particular low-fat cheese was the most sold brand of cheese in the supermarket. | CT | 127 customers | N/A | Supermarket | 10% low educational level (primary school or lower levels of high school) | Purchases of low-fat cheese | Collection of receipts | 12. Purchases of low-fat cheese were not affected | Strong |
Position nudges | ||||||||||||
 Kroese et al. [52] | 2016 | The Netherlands | Unhealthy snacks at the check-out counter were replaced by healthy snacks | CT | 2 intervention stores; 1 control store | ≤ 1 week | Small food store | N/A | Purchases of healthy snacks; Purchases of unhealthy snacks | Point-of-sale system | 1a. Healthy snack purchases increaseda 1b. Unhealthy snack purchases were not affected | Moderate |
 Meiselman et al. [53], study 1 | 1994 | UK | Candy was repositioned from four cash-points to one distant cash-point | Pre-post | 43 students | ≤ 1 week | University cafeteria | N/A | Choice for candy Energy intake | Questionnaire and food weighing | 2a. Candy selection decreaseda 2b. Energy intake was not affected | Weak |
 Meiselman et al. [53], study 2 | 1994 | UK | Potato chips were repositioned from meal line to distant snack bar | Pre-post | 60 students | >  1 week & ≤ 1 month | University cafeteria | N/A | Choice for potato chips | Questionnaire | 3. Potato chips selection decreaseda | Weak |
 Meyers et al. [54] | 1980 | USA | High calorie desserts were placed in the rear position on buffet line | Pre-post | 4412 food choices were observed | ≤ 1 week | Hospital cafeteria | N/A | Choice for high calorie desserts | Observer-reported | 4. High calorie dessert choice was not affected | Moderate |
 Rozin et al. [55], study 3 | 2011 | USA | Salad bar ingredients were placed on edge position of salad bar vs. middle position | Pre-post | 1 cafeteria | 1 < month(s) ≤ 6 | Hospital cafeteria | N/A | Purchases of salad bar ingredients | Food weighing | 5. Salad bar purchases increaseda | Moderate |
 Van Gestel et al. [56] | 2017 | The Netherlands | Unhealthy snacks at the check-out counter were replaced by healthy snacks | Pre-post | 1 small food store | >  1 week & ≤ 1 month | Small food store | N/A | Purchases of healthy snacks | Point of sale system | 6. Healthy snack purchases increaseda | Moderate |
 Chapman et al. [57], study 1 | 2012 | UK | Confectionery was removed from check-out counters and replaced by fruit | Pre-post | 1 cafeteria | ≤ 1 week | University cafeteria | N/A | Purchases of fruit; Purchases of confectionery | Point of sale system | 7a. Healthy fruit purchases decreaseda 7b. Unhealthy confectionary purchases increaseda | Moderate |
 De Wijk et al. [58] | 2016 | The Netherlands | Wholegrain bread was placed near entrance vs. away from entrance | CT | 2 supermarkets | 1 < month(s) ≤ 6 | Supermarket | N/A | Purchases of wholegrain bread | Point of sale system | 8. Healthy bread purchases were not affected | Moderate |
 Thorndike et al. [59] | 2017 | USA | Stores improved visibility of fruits and vegetables through new supplies (e.g., baskets, shelving) | RCT | 3 intervention stores; 3 control stores | 1 < month(s) ≤ 6 | Small food store | Store was located in low-income urban community | Purchases of fruits and vegetables | Point of sale system (WIC voucher redemption) | 9. Fruit and vegetable purchases increaseda | Moderate |
 Winkler et al. [60] | 2016 | Denmark | Sugar confectionery at one checkout counter was replaced by healthy snacks | CT | 4 intervention stores; 2 control stores | >  1 week & ≤ 1 month | Supermarket | N/A | Purchases of healthy snacks; Purchases of sugar confectionary | Point of sale system | 10a. Healthy snack purchases were generally not affected 10b. Unhealthy purchases were not affected | Moderate |
Mixed nudges | ||||||||||||
 Gittelsohn et al. [61] | 2013 | USA | Environmental changes included demonstrations of healthier cooking methods, taste-tests, and display of point-of-purchase materials (e.g., posters and shelf labels) | RCT | 98 participants from intervention condition; 47 participants from control condition | >  1 year | Supermarket | Years of schooling; 10.9y (intervention particpants) and 9.3y (control participants) | Healthy food purchasing score Unhealthy food purchasing score | Questionnaire | 1a. Healthy food purchasing score was not affected 1b. Unhealthy food purchasing score was not affected | Weak |
 Dorresteijn et al. [62] | 2013 | The Netherlands | Environmental changes included signage promoting low-sodium soup and low-fat croissants. Also, margarine was made less accessible whereas butter was made more accessible. | Pre-post | 1 cafeteria | >  1 week & ≤ 1 month | Hospital cafeteria | N/A | Purchases of normal soup Purchases of healthier soup Purchases of normal croissants Purchases of healthier croissants Purchases of butter Purchases of margarine | Point of sale system and hand-counts | 2a. Normal soup purchases were not affected 2b. Healthier soup purchases were not affected 2c. Normal croissant purchases were not affected 2d. Healthier croissant purchases were not affected 2e. Butter purchases increaseda 2 f. Margarine purchases decreaseda | Weak |
 Gamburzew et al. [63] | 2016 | France | Environmental changes included shelf labels indicating healthy foods, signage explaining the labelling system, placement strategies, and a taste-testing booth. | CT | 6625 customers | 1 < month(s) ≤ 6 | Supermarket | N/A | Purchases of targeted foods (fruits and vegetables; starches; meat/fish/eggs; mixed dishes and sandwiches; dairy products). | Point of sale system | 3a. Purchases of fruits and vegetables increaseda 3b. Purchases of starches increaseda 3c. Purchases of meat/fish/eggs were not affected 3d. Purchases of mixed dishes/sandwiches were not affected 3e. Purchases of dairy were not affected | Weak |
 Gittelsohn et al. [64] | 2010 | USA | Environmental changes included posters, shelf labels, cooking demonstrations and taste tests. | CT | 64 intervention participants; 53 control participants | 6 < months ≤12 | Supermarket | For intervention and comparison group, respectively: Years of schooling, 12.5y and 12.4y; Percentage unemployed, 35.9 and 18.8%. | Healthy food purchasing score Unhealthy food purchasing score Calorie intake | Questionnaires and dietary recall | 4a. Healthy food purchasing score was not affected 4b. Unhealthy food purchasing score was not affected 4c. Calorie intake was not affected | Strong |
 Foster et al. [65] | 2014 | USA | Environmental changes included placement strategies (multiple facings, prime placement), signage, shelf-tags, cross-promotion of healthy foods, and taste testing. | RCT | 4 intervention supermarkets; 4 control supermarkets | 6 < months ≤12 | Supermarket | Supermarkets located in low-income, high-minority neighborhoods | Purchases of targeted foods (milk, cereal, frozen meals, in aisle-beverages, checkout cooler beverages, water) | Point of sale system | 5a. Purchases of some targeted products within the milk category increaseda 5b. Purchases of cereals were not affected 5c. Purchases of some targeted products within the frozen meal category increaseda 5d. Purchases of some targeted products within the in-aisle beverages category decreased to a lesser extent in the intervention stores as compared to controla 5e. Purchases of check-out cooler beverages were not affected 5 f. Purchases of water increaseda | Moderate |
 Lawman et al. [66] | 2015 | USA | Availability of healthy foods was increased and promoted through banners, shelf labels, and recipes. A subset of stores was provided additional business trainings and mini-grants for storing their inventory of healthy foods (high-intensity intervention). | Pre-post | 8671 customers at baseline; 5949 customers at follow-up | 6 < months ≤12 | Small food store | N/A | Mean energy purchased | Observer reported | 6. The intervention did not affect mean energy purchased. | Moderate |
 Levy et al. [67] | 2012 | USA | Foods were labelled green, orange or red. Additionally, a choice architecture intervention was added which increased visibility and accessibility of green-labelled foods and beverages while decreasing the same for certain red-labelled items. | Pre-post | 4642 customers | 1 < month(s) ≤ 6 | Hospital cafeteria | 28% employed as service workers, administrative support, technicians | Purchases of green items Purchases of red items | Point of sale system | 7a. Green item purchases increased∞ 7b. Red item purchases decreased∞ | Strong |
 Lowe et al. [68] | 2010 | USA | Environmental changes included increased availability of foods lower in energy density. Additionally, a labelling system was introduced which color-coded food items. | Pre-post | 49 customers | 1 < month(s) ≤ 6 | Hospital cafeteria | N/A | Caloric content of purchases | Point of sale system | 8. Caloric content of purchases decreaseda | Moderate |
 Cardenas et al. [69] | 2015 | Peru | Fruit was repositioned from a distant position to a more accessible location near the point of purchase. Additionally, signage highlighted health benefits of fruit consumption. | Pre-post | 150 customers | >  1 week & ≤ 1 month | University cafeteria | N/A | Fruit purchases | Hand-counts | 9. Fruit purchases were not affected | Moderate |
 Thorndike et al. [70] | 2012 | USA | Foods were labelled red, yellow and green. Additionally, healthy foods were located to convenient positions and unhealthy options were made less convenient. | Pre-post | 1 cafeteria | 1 < month(s) ≤ 6 | Hospital cafeteria | N/A | Purchases of green items Purchases of red items | Point of sale system | 10a. Purchases of green items increased∞. 10b. Purchases of red items decreased∞ | Moderate |
 Steenhuis et al. [33] | 2004 | The Netherlands | In the food supply program, the availability of low-fat items increased and was made salient with signage. | RCT | 17 cafeterias were randomly assigned to either of 4 conditions (including control and food supply program) | 1 < month(s) ≤ 6 | Worksite cafeteria | 2% low educational level | Purchases of low-fat items | Point of sale system and questionnaire | 11. Purchases of low-fat items were not affected | Weak |
 Thorndike et al. [71] | 2014 | USA | Items were labelled green, yellow or red. Additionally, items were rearranged to make some of the green items more visible and some red items less visible. | Pre-post | 1 cafeteria | >  1 year | Hospital cafeteria | 29% low educated jobs (service workers, administrative support, technicians) | Purchases of green items Purchases of red items | Point of sale system | 12a. Purchases of green-labelled items increaseda 12b. Purchases of red-labelled items decreaseda | Weak |
 Seward et al. [72] | 2016 | USA | The full intervention included traffic-light labels, accessibility changes and tray stickers visualizing recommended portions of food types. The minimal intervention only included accessibility changes. | CT | 4 experimental cafeterias; 2 control cafeterias | 1 < month(s) ≤ 6 | University cafeteria | N/A | Purchases of green items Purchases of red items | Observer reported | 13a. Purchases of green items were not affected in neither full or minimal intervention cafeterias. 13b. Purchases of red items were not affected in neither full or minimal intervention cafeterias. | Moderate |
 Lee-Kwan et al. [73] | 2015 | USA | During phase 1, menus were revised to emphasize healthy foods with labels. Consecutively, during phase 2, (additional) healthy sides and beverages were introduced and promoted. | CT | 3 intervention stores; 4 control stores | 1 < month(s) ≤ 6 | Small food store | Carry-outs were based in low-income neighbourhoods | Purchases of healthy items | Point of sale system | 14. Purchases of healthy items were not affected. | Moderate |
Availability, size, functionality, and presentation nudges | ||||||||||||
 Diliberti et al. [74] | 2004 | USA | During baseline conditions, the portion size of the entree was the standard 100% portion; in the experimental condition the size was increased to 150%. | CT | 180 customers | >  1 week & ≤ 1 month | Cafeteria | N/A | Energy intake | Food weighing | Energy intake from the pasta entree, accompaniments, and entire meal increaseda | Moderate |
 Vandenbroele et al. [75] | 2018 | Belgium | Different sizes of sausages were available: a 150 g portion (default); a 125 g in-between portion; or a small, 100 g portion. | CT | 161 customers who bought targeted product | >  1 week & ≤ 1 month | Supermarket | N/A | Meat purchases | Point-of-sale system | The introduction of smaller portion size alternatives was associated with less meat being purchaseda | Moderate |
 Payne et al., study 1 [76] | 2016 | USA | Large green arrows were placed on the floor directing attention to the store’s produce section. | CT | 1 intervention store; 1 control store | >  1 week & ≤ 1 month | Supermarket | N/A | Purchases of fruit & vegetables | Point-of-sale system | Green arrows on floors were associated with increased fruit and vegetable purchasesa | Strong |
 Payne et al., study 2 [76] | 2016 | USA | Large green arrows were placed on the floor directing attention to the store’s produce section. | CT | 1 intervention store; 1 control store | >  1 week & ≤ 1 month | Supermarket | N/A | Purchases of fruit & vegetables | Point-of-sale system | Green arrows on floors were associated with increased fruit and vegetable purchasesa | Strong |
 Tal et al. [77] | 2015 | USA | Samples (no, apple, or cookie) were offered to participants at the entrance of the store | CT | 120 customers | N/A | Supermarket | N/A | Purchases fruit & vegetables | Observer-reported | Receiving an apple sample was associated with increased subsequent purchases of fruits and vegetables vs. cookie or no sample (p = 0.06). | Weak |