Association between the Phytochemical Index and Overweight/Obesity: A Meta-Analysis.

Nutrients. 2022;14(7)
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Overweight and obesity are characterized by abnormal or excessive fat accumulation that can damage health. Obesity is mainly caused by lifestyle, genetic and environmental factors. As a modifiable behaviour, eating behaviour plays an important role in the etiology of obesity. The phytochemical index/dietary phytochemical index (PI/DPI) is the percentage of total dietary calories derived from foods rich in phytochemicals. The aim of this study was to summarize published studies on the relationship between PI and the risk of overweight/obesity. This study is a meta-analysis of nine studies including 22 groups of data, with a total of 100,753 participants. Results showed that PI was inversely associated with the risk of overweight/obesity; with the increase in PI, the prevalence of overweight/obesity decreased gradually. Authors conclude that no conclusions can be drawn since all the studies included in this study were cross-sectional studies.

Abstract

Some studies suggest that a higher phytochemical index (PI) is associated with a lower risk of overweight/obesity. This meta-analysis is performed to summarize published studies on the relationship of PI and the risk of overweight/obesity. We searched on PubMed, Cochrane Library and Web of Science from the inception dates to February 2022. The random-effect model was used based on heterogeneity. Meta-regression was used to explore potential sources of between-study heterogeneity. Publication bias was evaluated using Begg's and Egger's tests. The dose-response relationship was assessed using a restricted cubic spline model. Nine studies were included in the meta-analysis, with a total of 100,753 participants. The meta-analysis showed that the phytochemical index was associated with a decreased risk of overweight/obesity. The pooled OR (95% CI) was 0.81 (0.74-0.90). The findings from dose-response analysis showed a nonlinear association between the phytochemical index and the risk of overweight/obesity. The results of the meta-regression showed that gender and area were significant covariates influencing the heterogeneity between studies. There was no publication bias in the meta-analysis of this study. In conclusion, although this meta-analysis indicates that a high phytochemical index is associated with a reduced risk of overweight/obesity, all the studies included in this meta-analysis were cross-sectional studies with high heterogeneity. As such, more data from randomized controlled trials are required to confirm the efficacy of PI in evaluating the risk of overweight/obesity.

Lifestyle medicine

Fundamental Clinical Imbalances : Structural
Patient Centred Factors : Triggers/Phytochemical index
Environmental Inputs : Diet ; Nutrients
Personal Lifestyle Factors : Nutrition
Functional Laboratory Testing : Not applicable

Methodological quality

Jadad score : Not applicable
Allocation concealment : Not applicable
Publication Type : Journal Article ; Meta-Analysis

Metadata

Nutrition Evidence keywords : Overweight ; Obesity ; Body mass index ; BMI ; Phytochemicals