Table 5.
Results of reviews on diet and physical activity combined, ordered by type of control and further ordered by mode of delivery of intervention.
| Review | Relevant studies, n (total studies) | Method of synthesis | Interventions | Outcomes | Follow-up | Summary of findings | AMSTAR-2 rating | |
| Mixed (active and nonactive) controls | ||||||||
|
|
Aalbers et al (2011) [47] | 5 (10) | Narrative synthesis of RCTsa and nonrandomized pre-post controlled trials | Internet | Body weight and body weight regain | 1.5-6.5 months | 40% (2/5) of studies reported effect sizes on body weight with small-to-medium significant effects; 1 study reported weight regain but did not reach significance. | Critically low |
|
|
Aneni et al (2014) [100] | 20 (29) | Narrative synthesis of RCTs | Internet | Weight, BMI, waist circumference, and body fat | 6-24 months | Modest improvements were observed in more than half of the studies with weight-related outcomes; 20 studies reported on body weight: 75% (15/20) of high quality and 5 of 20 (25%) low quality); 47% (7/15) high-quality studies reported significant improvement. | Critically low |
|
|
Beishuizen et al (2016) [102] | 7 (57) | Meta-analysis of RCTs | Internet | Systolic blood pressure, diastolic blood pressure, HbA1cb level, cholesterol level, weight, and level of physical activity | 3-60 months | There was a significant reduction in systolic blood pressure (MDc –2.66 mm Hg; 95% CI –3.81 to –1.52), diastolic blood pressure (MD –1.26 mm Hg; 95% CI –1.92 to –0.60), HbA1c level (MD –0.13%; 95% CI –0.22 to –0.05), LDLd cholesterol level (MD –2.18 mg/dL; 95% CI –3.96 to –0.41), weight (MD –1.34 kg; 95% CI –1.91 to –0.77), and an increase in physical activity (SMDe 0.25; 95% CI 0.10 to 0.39). | Low |
|
|
Fry et al (2009) [57] | 8 (19) | Narrative synthesis of all study types | Internet | Diet and physical activity | 8 weeks-30 months | There were generally positive effects of prompts; there was not enough evidence to know whether the medium in which prompts were sent through affected their effectiveness but personal contact with a counsellor did enhance effectiveness. | Critically low |
|
|
Hou et al (2013) [108] | 7 (38) | Narrative synthesis | Internet | Body fat, weight, and dietary fat intake | 0-12 months | In 71% (5/7) of studies, intervention groups lost more body fat, body weight, and dietary fat intake and maintained higher weight loss at 12 months. | Critically low |
|
|
Manzoni et al (2011) [62] | 26 (26) | Narrative synthesis of all study types | Internet | Weight loss and weight loss maintenance | 3-24 months | Internet-based weight loss interventions enhanced by professional feedback provided through the internet are more effective for weight loss than website-only programs but less effective than telephone counselling. 93% (13/14) of studies showed a further improvement in mean weight loss (weight maintenance) after the end of the trials. | Critically low |
|
|
Seo et al (2015) [69] | 31 (31) | Meta-analysis of RCTs | Internet | Waist circumference | 4 weeks-2 years | Internet-based interventions showed a significant reduction in waist circumference (mean change –2.99 cm; 95% CI −3.68 to −2.30; I2=93.3%) and significantly better effects on waist circumference loss (mean loss 2.38 cm; 95% CI 1.61 to 3.25; I2=97.2%) than minimal interventions such as information-only groups; no differences with respect to waist circumference change between internet-based interventions and paper-, phone-, or person-based interventions (mean change −0.61 cm; 95% CI −2.05 to 0.83; P=.42; k=31). | Critically low |
|
|
Sherrington et al (2016) [70] | 12 (12) | Meta-analysis of RCTs | Internet | Weight loss | 3-24 months | The internet-delivered weight loss interventions providing personalized feedback resulted in an MD of 2.13 kg (P<.001) greater weight loss in comparison with control groups receiving no personalized feedback. Heterogeneity levels showed considerable and significant heterogeneity (I2=99%; P<.001) between control groups not receiving personalized feedback and the internet-delivered weight loss interventions providing personalized feedback. | Critically low |
|
|
Elaheebocus et al (2018) [56] | 11 (134) | Narrative synthesis of RCTs | Social media | Body weight | 6-48 months | 82% (9/11) of studies using web-based social networks had positive results for weight loss. | Critically low |
|
|
Maher et al (2014) [61] | 5 (10) | Narrative synthesis | Social media | Weight | 8 weeks-24 months | Findings were mixed, from negligible to large effect sizes for weight loss. | Critically low |
|
|
Mita et al (2016) [65] | 10 (16) | Meta-analysis of RCTs | Social media | Weight change | 1-12 months | Meta-analysis of all trials showed no significant differences for body weight (significant mean difference 0.07; 95% CI −0.17 to 0.20). | Moderate |
|
|
Williams et al (2012) [75] | 10 (22) | Meta-analysis of RCTs | Social media | BMI; body weight; diet | 3 months-24 months | Meta-analysis showed no significant differences in changes in weight (SMD 0; 95% CI −0.19 to 0.19; 10 studies); however, pooled results from 5 studies showed a significant decrease in dietary fat consumption with social media (SMD −0.35; 95% CI −0.68 to −0.02). | Critically low |
|
|
Willis et al (2017) [76] | 5 (5) | Narrative synthesis of all study types | Social media | Body weight; body composition; blood pressure; and blood markers | 8 weeks-6 months | 100% (5/5) of studies reported a reduction in baseline weight. 60% (3/5) of studies reported significant decreases in body weight when online social networks was paired with health educator support. Only one study reported a clinically significant weight loss of 55%. | Critically low |
|
|
Bacigalupo et al (2013) [50] | 5 (7) | Narrative analysis of RCTs | Mobile | Weight loss and BMI | 9-52 weeks | Strong evidence for weight loss in the short term with moderate evidence for the medium term. | Low |
|
|
Covolo et al (2017) [104] | 21 (40) | Narrative synthesis of RCTs | Mobile | BMI and waist circumference | 6-12 months | 62% (13/21) of studies did not find a statistical difference in changes in weight. 24% (5/21) of studies found that a mobile app was more effective compared with controls (P<.05). In 3 studies, this did not differ significantly between the 2 groups. | Critically low |
|
|
Head et al (2013) [107] | 3 (19) | Meta-analysis of RCTs | Mobile (SMS text messaging) | Weight | Mean 81.26 days | The weighted mean effect size for weight loss was Cohen d=0.255 (95% CI .056 to .455; P=.01; k=3). | Critically low |
|
|
Liu et al (2015) [59] | 9 (14) | Meta-analysis of RCTs | Mobile | Weight and BMI | 3-30 months | Compared with the control group, mobile phone intervention was associated with significant changes in body weight and body mass index (weight [kg]/height (m2) of −1.44 kg (95% CI −2.12 to −0.76) and −0.24 units (95% CI −0.40 to −0.08), respectively; no differences between shorter and longer trials (< or ≥6 months; k=22). | Critically low |
|
|
Lyzwinksi et al (2014) [60] | 8 (17) | Meta-analysis of RCTs | Mobile | Body weight and BMI | 8 weeks-12 months | 75% (6/8) of studies of mobile phone interventions found significant changes in weight favoring the mobile phone intervention groups over the controls; the meta-analysis generated a medium, significant effect size of 0.430 (95% CI 0.252 to 0.609; P≤.01), favoring mobile interventions. | Critically low |
|
|
Palmer et al (2018) [111] | 3 (71) | Meta-analysis of RCTs | Mobile | Body weight and triglyceride levels | 24 hours-6 months | There were, at best, modest benefits of diet and physical activity interventions. The effect of SMS text messaging–based diet and physical activity interventions on incidence of diabetes was pooled (risk ratio 0.67; 95% CI 0.49 to 0.90; I2=0.0%); end point weight was pooled (MD −0.99 kg; 95% CI −3.63 to 1.64; I2=29.4%); percentage change in weight was pooled (MD −3.1; 95% CI −4.86 to −1.3; I2=0.3%); and triglyceride levels was pooled (MD −0.19 mmol/L; 95% CI −0.29 to −0.08; I2=0%). | Moderate |
|
|
Schoeppe et al (2016) [68] | 10 (27) | Narrative synthesis of RCTs, randomized trials, controlled trials, and pre- and poststudies | Mobile | Physical activity; diet; weight status; BMI; blood pressure; sedentary behavior; and fitness | 1-24 weeks | 40% (4/10) of studies that measured weight reported significant improvement in weight status; apps were more successful when used alongside other intervention components than when used alone. | Critically low |
|
|
Siopis et al (2015) [71] | 6 (14) | Meta-analysis of RCTs, quasi-RCTs, and pre-post studies | Mobile | Body weight and BMI | 8 weeks-12 months | The weighted mean change in body weight in intervention participants was −2.56 kg (95% CI −3.46 to −1.65) and in controls, −0.37 kg (95% CI −1.22 to 0.48). | Critically low |
|
|
Wieland et al (2012) [74] | 18 (18) | Meta-analysis of RCTs, quasi-RCTs, and quasiexperimental studies | Computer based | Weight | 4 weeks-30 months | At 6 months, computer-based interventions led to greater weight loss than minimal interventions (MD −1.5 kg; 95% CI −2.1 to −0.9; 2 trials) but less weight loss than in-person treatment (MD 2.1 kg; 95% CI 0.8 to 3.4; 1 trial). At 6 months, computer-based interventions were superior to a minimal control intervention in limiting weight regain (MD −0.7 kg; 95% CI −1.2 to −0.2; 2 trials) but not superior to infrequent in-person treatment (MD 0.5 kg; 95% −0.5 to 1.6; 2 trials). | Critically low |
|
|
Afshin et al (2016) [99] | 35 (224) | Narrative synthesis and meta-synthesis for RCTs and quasiexperimental studies | Various: internet and mobile | Weight | 3-30 months | 69% (24/35) of studies reported significant improvements in adiposity following the intervention. 81% (13/16) of RCTs reported significant reductions in adiposity; using the internet in the weight loss program resulted in 0.68 kg (95% CI 0.08 to 1.29 kg) additional weight reduction over a period of 3 to 30 months; in studies finding significant weight reduction, the magnitude of weight change ranged from 1 to 6 kg after 6 months of follow-up. | Critically low |
|
|
Allen et al (2014) [48] | 38 (39) | Narrative synthesis of randomized trials | Various: internet, messaging, chat rooms, and mobile | Weight loss | 5 weeks-24 months | 53% (21/39) of RCTs reported statistically significant weight loss in the intervention group as compared with the control group; the proportion varied by mode of delivery, the highest proportion of successful trials involving SMS text messaging or email (67%), followed by online chat rooms (50%), web-based (48%), and self-monitoring with technology (43%). | Critically low |
|
|
Bassi et al (2014) [51] | 8 (28) | Narrative analysis of RCTs | Various: internet and mobile | BMI and weight | 12 months | Results were mixed; 2 studies reported significant improvements with weight loss; however, effects were typically short lived, and more weight is regained in a primarily technology-based approach, as compared with personal contact. | Critically low |
|
|
Carvalho de Menzes et al (2016) [53] | 18 (18) | Narrative synthesis of all study types | Various: email, telephone, face-to-face, and websites | Fat consumption, fruit and vegetable consumption, and physical activity | 1-36 months | Approximately half the studies showed weight loss in the intervention group. | Critically low |
|
|
Coons et al (2012) [54] | 13 (13) | Narrative synthesis of RCTs | Various: PDAf, web-based, and wearables | Body mass; BMI; BPg; waist circumference; RHRh; physical activity; body fat percentage; energy intake; and EEi | 12 weeks-24 months | 50% (6/12) of weight loss trials reported significantly greater weight loss among individuals randomized to technology interventions compared with controls; insufficient evidence to determine the effectiveness of interventions for weight maintenance. | Critically low |
|
|
Dutton et al (2014) [55] | 18 (22) | Narrative synthesis of all study types | Various: mobile, internet, and podcasts | Weight | 3 weeks-24 months | 67% (12/18) of trials found significant differences in weight loss at one or more assessments. | Critically low |
|
|
Maxwell (2015) [64] | Not reported | Narrative synthesis of all study types | Technology interventions, including web-based and mobile | Healthy eating and active living | Not reported | Men participate in technology-based healthy lifestyle interventions less than women; maintenance of behavior is challenging. | Critically low |
|
|
Podina and Fodor (2018) [66] | 43 (47) | Meta-analysis of RCTs | Various: mobile messaging, mobile app, and website | Weight, BMI, waist circumference, and percentage of body fat | 3-24 months | Standard active treatment was more effective than eHealth interventions with regard to weight (g=−0.31; 95% CI − 0.43 to −0.20). There was a statistically significant, albeit small effect size favoring eHealth interventions relative to passive control groups for weight (g=0.34; 95% CI 0.24 to 0.44) and behavioral outcomes (g=0.17; 95% CI 0.07 to 0.27). | Critically low |
|
|
Ryan et al (2019) [67] | 6 (6) | Narrative synthesis of randomized trials | Various: mobile or internet | Weight loss | 5 weeks-24 months | Tailored interventions were found to be more effective in supporting weight loss than generic or waitlist controls in 66% (4/6) of articles. Effect sizes were very small to moderate, with evidence of fluctuations in effect sizes and differences of effect between tailored and nontailored interventions, and between tailoring types, over time. | Critically low |
| Nonactive controls | ||||||||
|
|
An et al (2017) [49] | 21 (22) | Meta-analysis of RCTs, pre-post studies, and cohort studies | Social media | Physical activity; sedentary behavior; diet; BMI; hip-waist ratio; body fat; and waist circumference | 2-102 weeks | Social media–based interventions were found to reduce body weight by 1.01 kg (95% CI 0.45 to 1.57), BMI by 0.92 kg/m2 (95% CI 0.29 to 1.54), and waist circumference by 2.65 cm (95% CI 0.86 to 4.43). | Critically low |
|
|
Tang et al (2016) [72] | 18 (27) | Meta-analysis of RCTs | Various | Body weight; BMI; and waist circumference | 1-24 months | Participants receiving internet-based, self-directed interventions lost significantly more weight than those receiving minimal intervention or no treatment (MD −1.72 kg; 95% CI −2.60 to −0.84; significant mean difference −0.45; 95% CI −0.67 to −0.23; I2=80%; P<.001) and a significantly greater reduction in BMI levels than those receiving no treatment or minimal intervention (MD −0.47 kg/m2; 95% CI −0.81 to −0.14; significant mean difference −0.32; 95% CI −0.61 to −0.03; I2=90%; P=.03; 13 evaluations). There was a greater reduction in BMI (MD 0.54 kg/m2) and waist circumference (2.81 cm) at 0-4 months follow-up than at later times (k=27). | Critically low |
| Active controls | ||||||||
|
|
Beleigoli et al (2019) [52] | 11 (11) | Meta-analysis of RCTs | Internet | Weight and BMI | 3-12 months | Compared with offline interventions, digital interventions led to a greater short-term (<6 months follow-up) weight loss (MD −2.13 kg; 95% CI −2.71 to −1.55; 393 participants; high-certainty evidence) but not in the long-term (MD −0.17 kg; 95% CI −2.10 to 1.76; 1104 participants; moderate-certainty evidence). | Critically low |
|
|
Kodama et al (2012) [58] | 23 (23) | Meta-analysis of RCTs | Internet | Weight loss | 3-30 months | Using the internet had a modest but significant additional weight loss effect compared with nonweb user control groups (−0.68 kg; P=.03). Internet-based interventions were effective for weight loss (−1.00 kg; P<.001) but not a substitute for face-to-face support (+1.27 kg; P=.01). An additional effect on weight control was observed when the aim of using the internet was initial weight loss (−1.01 kg; P=.03) but was not observed when the aim was weight maintenance (+0.68 kg; P=.26); furthermore, it was effective to use the internet as an adjunct to face-to-face care (−1.00 kg; P<.001) but adverse effects on weight loss were found when it was used as a substitute (+1.27 kg; P=.01). The weight loss effect was insignificant (−0.20 kg; P=.75) in studies with educational periods ≥12 months and was significant in studies with an educational period <6 months (−1.55 kg; P=.001). | Critically Low |
aRCT: randomized controlled trial.
bHbA1c: glycated hemoglobin.
cLDL: low-density lipoprotein.
dMD: mean difference.
eSMD: standardized mean difference.
fPDA: personal digital assistant.
gBP: blood pressure.
hRHR: resting heart rate.
iEE: energy expenditure.