Table 1 Characteristics of included studies (randomized controlled trials)

Reference no.

33

34

35

Author

Vermeer et al.

Lowe et al.

Thorndike et al.

Year

2011

2010

2016

Country

Netherlands

USA (Philadelphia)

USA (Massachusetts)

Type of study

Cluster RCT

RCT

RCT

Participants

Hospital: N = 15, company: N = 5, university: N = 3, police department: N = 2

Hospital: N = 2 cafeterias in hospital or university employees

Hospital: N = 2 cafeterias in hospital where employees were working

Total study population (I/C)

Pre: 499 (184, 135/180)

Post: 308 (129, 75/104)

96 (47/49)

Sex

Males and females;

male 50%

Males and females

(18, 78),

EC (11, 38),

ECPls (7, 40)

Male and females; feedback incentive (72, 28), feedback only (73,27), control (72, 28)

Age

18–79 years; mean (SD) = 39.18 (11.26)

21–65 years

18–50 and over

Intervention duration

3 months

3 months

3 months

Follow-up

–

6 months, 12 months

1 month, 2 months, 3 months

Intervention program

1. Intervention group 1 (N = 9): price was 65% of the standard price. About 2/3 of the size of the standard portion was offered.

2. Intervention group 2 (N = 8); price was 80% of the standard price. A smaller portion size was added to the assortment and value-size pricing (a lower price per unit for large portions than for small portions).

1. Intervention group (density education and incentive): environmental change (EC)-plus

・Financial discounts: 15% discount (low-energy density) or 25% discount (very low-energy density) for cafeteria food items which were lower in energy density (e.g., soups, salads, diet soda, any entrees or side dishes etc., labeled as low or very low in energy density)

*Green: very low in energy density (< 0.6 kcal/g)

*Yellow: low in energy density (< 0.6–1.5 kcal/g)

*Orange: medium in energy density:

(< 1.6–3.9 kcal/g)

*Red: high in energy density: (< 4.9–9.0 kcal/g)

・Group sessions (four time × 60 min) during which subjects were informed about the energy density of different food items.

1. Intervention group 1 (feedback incentive):

・Rewards for achieving “green goal” (40%, 60%, 80%) of all cafeteria purchases. Each time the goal was achieved in a month, $10 was earned as a reward.

・Same as feedback-only group

Control program

1. The control group (N = 8): the standard size of hot meal was offered.

1. Control group (only environmental changes): EC・(same as EC-plus)・No financial discounts No group session

1. Control group (no contact)

2. Feedback only (four letters sent over a period of 3 months; explanation of traffic light system or the proportion of employee’s traffic light group purchases)

ITT*

No; pre-post

Yes

No; pre-post

Outcome

Primary outcome:

BMI

Secondary outcome:

Fried snacks

Primary outcome:

weight change

Secondary outcomes:

Cholesterol

(TC, HDL, LDL),

blood pressure

(no outcome data),

food intake

(fruits, meats, dairy, breads, dairy products, fat and sweets),

nutritional intake

(total energy kcal), sales data (purchased energy [kcal] and purchased proportion of calories from fat, protein, and carbohydrate)

Primary outcome: none

Secondary outcomes: inappropriate