Endocrine Abstracts

Background: By focusing on nutrition transition in the Middle East and North Africa, this study aim to investigate the general structure and secular trend of dietary patterns extracted from the Tehran Lipid and Glucose Study (TLGS) and adherence to these dietary patterns among Iranian population from 2006 till 2017.

Methods: We investigated on four examination surveys of TLGS including survey 1 (2006–2008), survey 2 (2009–2011), survey 3 (2012–2014), and survey 4 (2015–2017). The dietary intakes was gathered by a validated and reliable food frequency questionnaire. Generalized Estimating Equations was used to assess secular trends in anthropometric, biochemical, and dietary variables across the study period. To identify general structure and secular trend of dietary patterns during each survey, principle component analysis (PCA) and K–mean cluster analysis were used, respectively.

Results: After adjusting for potential confounders including age, sex, body mass index, and total energy intake, the carbohydrate and protein intake gradually increased and the total fat intake decreased during study period (P–value <0.001); however total energy intake remained stable. During the study period, participants consumed notable less refined grain, solid fat, dairy products, and simple sugar. Snack and dessert consumption increased and meat intake had no significant changes during a decade (all P–values <0.001). Three dietary patterns were extracted buy using PCA including: Healthy dietary pattern characterized by higher intake of vegetable, fruit, dairy products, liquid oil, nuts and seeds, and honey and jam, Western dietary pattern featured by refined grain, solid fat, meat, snack and dessert, potato, and soft drink, and the Mixed dietary pattern highlighted by tea and coffee, and simple sugar. Based on cluster analysis, 27.8% of participants in survey 4 followed a Western dietary pattern, and 34.1% followed the Mixed dietary pattern. The Healthy dietary pattern was stable among study population during the last decade.

Conclusions: The structure and the type of foods that population have chosen to eat had changed since 2006. And a new secular trend in dietary patterns including a stability of Healthy dietary pattern, a decline of the Western dietary pattern and an increase in the Mixed dietary pattern was presented in our investigation.

Keywords: dietary patterns, secular trend, nutrition transition, factor analysis, adults, TLGS.