The contribution of poor diet quality, as assessed by diet quality indices, to weight gain has not been fully elucidated.
To evaluate the association between diet quality and body weight change in adults by synthesizing the best available evidence on the relationship between overall diet quality and weight change over time.
Types of participants
Adults aged ≥ 18 years at baseline.
Types of intervention(s)/phenomena of interest
Studies assessing dietary intake, total energy intake (TEI), energy density (ED) or total fat reported as the main exposure variable.
Types of studies
Cohort studies with longitudinal data analysis.
Types of outcomes
Studies reporting change in body weight as the outcome.
A search of four databases (MEDLINE, CINAHL, EMBASE and Scopus) was performed from 1970 to March 2011 for English language cohort studies. Search terms included diet quality and weight status.
Study quality was assessed using standardised critical appraisal instruments from the Joanna Briggs Institute, Meta-Analysis of Statistics Assessment and Review Instrument (MAStARI).
The first author extracted the data from included studies using a standardised data extraction tool from JBI-MAStARI with a second reviewer checking the data extracted for accuracy.
It was not possible to pool results in meta-analysis; thus this systematic review tabulated the results of the included studies.
From 2304 studies identified, 32 studies met all inclusion criteria. Eight focused on diet quality indexes, seven on dietary patterns identified from factor or cluster analysis, and 17 studies used nutrient-based approaches including fat intake, TEI or ED.
Additional studies are needed that examine diet quality as a predictor of weight gain. Currently, the majority of studies use factor or cluster analysis to examine diet quality, but these comparisons represent very different dietary patterns. Currently no studies have applied factor or cluster analysis along with a diet quality index within the same population. This systematic review has highlighted the limitations and inconsistencies for the few studies that have examined EI, ED or total fat intake and weight change over time.
1. Priority Research Centre in Physical Activity and Nutrition, University of Newcastle, Callaghan, New South Wales, Australia
2. School of Health Sciences, University of Newcastle, New South Wales, Australia
3. Faculty of Nutrition and Health Science, King Abdul-Aziz University, Jeddah, Saudi Arabia University of Newcastle, Callaghan, NSW, 2308, Australia
4. Faculty of Health, University of Technology Sydney, New South Wales, Australia
5. The University of Newcastle Evidence Based Health Care Group: a JBI Evidence Synthesis Group