A recent study found that consumption of 100% fruit juice – despite this being a convenient source of vitamins, antioxidants and polyphenols – led to weight gain and an increased body mass index (BMI) in children.
Researchers, led by University of Toronto scientists, whose findings were published in JAMA Paediatric, wrote that there were concerns about the link between 100% fruit juice and weight gain, because of the high levels of free sugars and energy in these beverages, and because limited fibre in juice, compared to whole fruits, might lead to lower satiety and increased energy intake.
The aim of the systematic review and meta-analysis was to evaluate the evidence on 100% fruit juice consumption and weight gain in paediatric and adult populations to inform public policy and clinical guidelines, reports News-Medical.net.
For their research, the team searched the MEDLINE, Embase and Cochrane databases from their inception until 18 May 2023.
Prospective cohort studies of at least six months, as well as randomised clinical trials (RCT) with interventions of two weeks or longer, were included in the analysis.
A total of 17 prospective cohort studies included children with a median age of eight-years-old, whereas six prospective cohort studies included adults with a median age of 48.
Although no RCTs involving children were identified in the analysis, 19 RCTs involving adults with a median age of 42 were identified. The included RCTs compared 100% pomegranate, berries, tart cherry, apple, citrus, or grape juice with standard diet alone or non-caloric controls such as water or non-nutritive sweetened beverages.
The primary outcome was the change in BMI and body weight for every 250ml serving increment of 100% fruit juice for children and adults, respectively. Studies reporting changes in juice intake compared to weight were separately analysed.
The main analysis used estimates unadjusted for energy intake, and a secondary meta-analysis considered estimates that were adjusted for total energy intake. Additionally, an analysis extrapolating BMI or body weight change to a year-long period was conducted.
Findings
The risk of bias analysis indicated high quality of the included studies. However, a publication bias was evident in cohort studies in children, said the authors.
A positive association was observed between 100% fruit juice consumption and weight gain in children. Prospective studies not adjusting for energy intake showed a significant positive association between 100% fruit juice consumption and body weight gain in adults, whereas studies adjusting for energy intake found a significant inverse association, thus suggesting that energy intake may mediate this relationship.
Comparatively, in RCTs involving adults, no significant association was observed between the consumption of 100% fruit juice and body weight change.
Notable limitations of the study include potential residual confounding in observational designs, inaccuracies in self-reported dietary assessments, substantial heterogeneity in outcomes, and a lack of RCTs in children, emphasising the need for future research in this area.
The scientist said analysis identified a positive association between 100% fruit juice consumption, slight BMI gain in children, and slight weight gain in adults, which was potentially mediated by calories. These findings support limiting the consumption of 100% fruit juice to prevent obesity and improve public health outcomes.
Study details
Consumption of 100% fruit juice and body weight in children and adultsa systematic review and meta-analysis
Michelle Nguyen, Sarah Jarvis, Laura Chiavaroli, et al.
Published in JAMA Paediatric on 16 January 2024
Key Points
Question
What is the association between 100% fruit juice intake and body weight in children and adults?
Findings
This systematic review and meta-analysis of 42 eligible studies, including 17 among children (n = 45 851) and 25 among adults (n = 268 095), found a positive association between intake of 100% fruit juice and weight gain in children. Analysis of cohort studies in adults found a significant positive association among studies unadjusted for total energy, suggesting potential mediation by calories; an analysis of trials in adults found no significant association between 100% fruit juice consumption and body weight.
Meaning
Study findings support guidance to limit consumption of fruit juice to prevent the intake of excess calories and weight gain.
Abstract
Importance
Concerns have been raised that frequent consumption of 100% fruit juice may promote weight gain. Current evidence on fruit juice and weight gain has yielded mixed findings from both observational studies and clinical trials.
Objective
To synthesise the available evidence on 100% fruit juice consumption and body weight in children and adults.
Data Sources
MEDLINE, Embase, and Cochrane databases were searched through May 18, 2023.
Study Selection
Prospective cohort studies of at least six months and randomised clinical trials (RCTs) of at least two weeks assessing the association of 100% fruit juice with body weight change in children and adults were included. In the trials, fruit juices were compared with non-caloric controls.
Data Extraction and Synthesis
Data were pooled using random-effects models and presented as β coefficients with 95% CIs for cohort studies and mean differences (MDs) with 95% CIs for RCTs.
Main Outcomes and Measures
Change in body mass index (BMI; calculated as weight in kilograms divided by height in metres squared) was assessed in children and change in body weight in adults.
Results
A total of 42 eligible studies were included in this analysis, including 17 among children (17 cohorts; 0 RCTs; 45 851 children; median [IQR] age, 8 [1-15] years) and 25 among adults (6 cohorts; 19 RCTs; 268 095 adults; median [IQR] age among cohort studies, 48 [41-61] years; median [IQR] age among RCTs, 42 [25-59]). Among cohort studies in children, each additional serving per day of 100% fruit juice was associated with a 0.03 (95% CI, 0.01-0.05) higher BMI change. Among cohort studies in adults, studies that did not adjust for energy showed greater body weight gain (0.21 kg; 95% CI, 0.15-0.27 kg) than studies that did adjust for energy intake (−0.08 kg; 95% CI, −0.11 to −0.05 kg; P for meta-regression <.001). RCTs in adults found no significant association of assignment to 100% fruit juice with body weight but the CI was wide (MD, −0.53 kg; 95% CI, −1.55 to 0.48 kg).
Conclusion and Relevance
Based on the available evidence from prospective cohort studies, in this systematic review and meta-analysis, one serving per day of 100% fruit juice was associated with BMI gain among children. Findings in adults found a significant association among studies unadjusted for total energy, suggesting potential mediation by calories. Further trials of 100% fruit juice and body weight are desirable. Our findings support guidance to limit consumption of fruit juice to prevent intake of excess calories and weight gain.
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