Table 1 Characteristics of included studies (n = 30)

Abu-Saad 2019 [33]

Israel

50

53 y

58% female

Not rural

Secondary – participants with T2DM

Pilot two-arm un-blinded RCT

6 mo

BL, 3 mo, 6 mo, 12 mo

Diabetes-related dietary knowledge

Vegetable, fruit, wholegrain, added sugars, dietary fibre intake

PA, adiposity, HbA1c

NS increase vs CG (4.2 vs 3.4 portions/d)

No

Alonso-Dominguez 2019 [34]

Spain

204

61 y

46% female

Not rural

Secondary – participants with T2DM

Two-arm RCT

12 mo

BL, 3 mo, 12 mo

Mediterranean Diet Adherence Screener (including ≥ 2 serves/d vegetables)

Diet Quality Index, clinical measures

NS increase adherence at 12 mo (11%) vs BL

No

Bhurosy 2020 [35]

US

165

19 y

86% female

Not rural

Primary – diet

RCT

3 d

Day 1, day 2, day 3

Red/orange vegetable intake

S increase from

0.9 ± 0.9 times/d on day 1 to 1.6 ± 

1.3 times/d on day 2 and to 1.3 ± 

1.3 times/d on day 3. NS increase in the CG

Yes

Bozorgi 2021 [36]

Iran

120

52 y

40% female

Not rural

Secondary – participants with hypertension

Two-arm RCT

6 mo

BL, 2 mo, 6 mo

Adherence to medication

DASH (including vegetable intake), blood pressure, PA

Increase in IG (n = 19 by > 2 serves/d; no statistical comparison)

No

Brown 2014 [37]

US

150

22 y

Sex NA

Not rural

Primary – diet

Pilot two-arm RCT

7 wk

BL, 7 wk

MyPlate food group recognition

Vegetable, fruit intake

Trend in increase in intervention group (data not shown)

No

Cantisano 2022 [56]

Spain

16

21 y

100% female

Not rural

Primary – diet and lifestyle

Pre-post trial

3 mo

BL, 3 mo

Dietary intake (Global Diet Quality Index, 8 FG including vegetables)

PA, lifestyle and wellbeing

S increase of 3.75 score vs BL (P = 0.005)

Yes

Celis-Morales 2016 [57]

Ireland, NL, Spain, Greece, UK, Poland, Germany

1269

40 y

59% female

Not rural

Primary – diet and PA

Four-arm RCT

6 mo

Low intensity: BL, 3, 6 mo

High intensity: BL, 1, 2, 3, 6 mo

Dietary intake (9 FG including vegetables),

Healthy Eating Index

Anthropometric measures (Weight, BMI, waist), biomarkers

NS increase of 2.0 g/day (P = 0.81) between CG and IG

No

Chan 2020 [38]

US

160

70 y

100% men

Not rural

Secondary – participants with prostate cancer

Pilot four-arm RCT

3 mo

BL, 3, 6 mo

Feasibility

Diet score, dietary intake (7 FG including cruciferous vegetables), PA

S increase in vs CG (0.29 serves/d)

Yes

Debon 2020 [39]

Brazil

39

59 y

82% female

Not rural

Secondary – participants with hypertension

Pilot non-blinded non- randomized, controlled trial

3 mo

BL, 3 mo

Dietary intake (10 FG including vegetables), self-care, biomarkers, blood pressure

NS increase in vegetable intake in the IG vs BL (0.95 serves/wk)

No

Elbert 2016 [40]

NL

146

41 y

73.3% female

Not rural

Primary—diet

RCT

6 mo

BL, 6 mo

Fruit and vegetable intake overall and by health literacy

Self-efficacy in eating fruit and vegetables

NS increase IG vs BL. S increase in participants with high health literacy vs low

No

Fjeldsoe 2019 [41]

Australia

114

54 y

67% female

Not rural

Primary—lifestyle

RCT

12 mo

BL, 6, 12 mo

Fruit, vegetable, SSB intake, takeaway meals, fat, fibre index, weight, PA

NS increase in serves/day vs BL (0.10; 95% CI: − 0.32 to 0.53)

No

Gilson 2017 [42]

Australia

19

48 y

Not rural

Primary—diet and physical activity

Pilot non-randomised uncontrolled trial

5 mo

BL, 5 mo, 2 mo follow up

Fruit, vegetable, saturated fat, SSB, PA

Sedentary periods

S increase by 1 serve/d vs BL (P = 0.024)

Yes

Goni 2020 [43]

Spain

720

60 y

24% female

Not rural

Secondary – participants with atrial fibrillation

Single-blind RCT

2 y

BL, 1, 2 y

Mediterranean diet (including vegetables)

NS increase vs CG (-20 g/day 2-y change)

No

Hansel 2017 [44]

France

120

57 y

67% females

Not rural

Secondary – participants with T2DM and abdominal obesity

Two-arm open-label RCT

4 mo

BL, 3, 6 mo

International

Diet Quality Index (including vegetables)

Weight, HbA1c, measured maximum oxygen consumption

S increase 0.3 points vs CG (-0.3; P = 0.01)

Yes

Hebden 2014 [45]

Australia

51

23 y

81% female

Not rural

Secondary – participants with overweight or obesity

Pilot two-arm RCT

3 mo

BL, 3 mo

Weight, BMI

Vegetable, SSB intake, takeaway meals, PA

NS increase

vs CG

No

Hendrie 2020 [58]

Australia

1224

48 y

84% female

Not rural

Primary—diet

Pre-post trial

90 d

BL, 21, 90 d

Vegetable intake and variety

Psychological variables (attitudes, intentions, self-efficacy, and action planning) and app usage

S increase of 0.48 serves/d and 0.35 types /d vs BL

Yes

Jahan 2020 [46]

Bangla-desh

412

47 y

86% female

Rural

Secondary – participants with hypertension

Two-arm open-label RCT

5 mo

BL, 5, 12 mo

Salt, fruit, vegetable intake, blood pressure, weight, PA

Dietary salt excretion, glucose, quality of life

NS increase (1% more increased vs CG)

No

Kerr 2016 [52]

Australia

247

24 y

65% female

Not rural

Primary—diet

Three-arm RCT

6 mo

BL, 6 mo

Fruit, vegetables, SSB, energy-dense nutrient-poor foods and beverages

Weight, BMI

NS decline vs CG (-0.1 serves/d)

No

Lara 2016 [47]

UK

70

61 y

75% female

Not rural

Primary—lifestyle

Pilot two-arm single-blinded RCT

2 mo

BL, 2 mo

Mediterranean diet (including vegetables), PA, healthy ageing

Decline (2.6 portions/d) vs BL (2.4 portions/d)

(no statistical comparison)

No

Lombard 2016 [48]

Australia

649

40 y

100% female

Rural

Primary—weight management

Cluster RCT (by town)

12 mo

BL, 12 mo

Weight loss

Diet quality, greater self-management

behaviours (including vegetables)

NS increase in IG by 3 g/d

No

Perez-Junkura 2022 [59]

Spain

27

37 y

81% female

Not rural

Primary—diet

Non-randomised, uncontrolled trial

12 mo

BL, 12 mo

Dietary intake (including vegetables)

Gastrointestinal symptoms

NS increase vs BL by 0.7 portions/d

No

Plaete 2015 [60]

Belgium

426

32 y

60% female

Not rural

Primary—diet

Three arm- non-randomised controlled trial

1 mo

BL, 1 wk, 1 mo

Fruit, vegetable intake

S increase vs BL (IG1: χ2 1 = 5.3, p = 0.02; IG2: χ2 1 = 12.8, p < 0.001). NS increase in CG

Yes

Pope 2019 [49]

US

38

22 y

74% female

Not rural

Primary—lifestyle

Two-arm, RCT

3 mo

BL, 1.5 mo, 3 mo

Feasibility

Fruit, vegetable, wholegrains, SSB, calories, PA, physiology, weight

Decline vs BL (no statistical comparison)

No

Recio-Redruguez 2016 [50]

Spain

833

52 y

62% females

Not rural

Primary—diet

Two-arm RCT

3 mo

BL, 3 mo

Mediterranean diet (including vegetables), PA

Blood pressure, BMI, biomarkers

NS decline vs CG (-4% ≥ 2 serves/d)

No

Schulz 2014 [51]

NL

5055

44 y

47% female

Not rural

Primary -lifestyle

Three-arm RCT

2 y

BL, 1, 2 y

Overall risk score

Fruit, vegetable intake, alcohol, smoking, PA

NS increase vs CG (β 0.07, P = 0.62)

No

Turner-McGrievy 2013 [53]

US

96

43 y

75% female

Not rural

Secondary – participants who are overweight

Post hoc analysis of RCT

6 mo

BL, 3, 6 mo

Weight

Fruit, vegetables intake, PA

NS increase between app, paper journal or website P = 0.67)

No

Wang 2021 [54]

China

110

18 y

59% female

Not rural

Primary—lifestyle

Non-randomized controlled trial

21 d

BL, 21 d

Dietary intake (including vegetables)

PA, fitness, body composition

S increase vs BL (0% vs 7% ≥ 500 g/d). NS increase in CG

Yes

Wang 2020 [55]

Mongolia

171

51 y

57% males

Not rural

Secondary – participants with T2DM

Two-arm RCT

12 mo

BL, 12 mo

Plasma glucose

Fruit, vegetable intake, PA, smoking, weight control

S increase in % who increased intake vs CG (87% vs 29%; p < 0.001)

Yes

Williams 2022 [61]

Australia

477

52 y

78% female

Not rural

Primary – diet and lifestyle

Two-arm RCT

3 mo

BL, 1, 3 mo

Healthcare professional visitations

PA, BMI, fruit, vegetable intake

NS increase in meeting guidelines vs CG (0.90 [0.39, 2.10])

No

Zenun Frano 2022 [62]

UK

187

43 y

84% female

Not rural

Primary—diet

Two-arm, single-blinded RCT

3 mo

BL, 3 mo

m-AHEI (including vegetable scores)

Weight, BMI, PA

NS decline vs CG (-0.32 m-AHEI points)

No