Nutrient patterns and their relation to general and abdominal obesity in Iranian adults: findings from the SEPAHAN study.

BACKGROUND

Few studies have linked major dietary nutrient patterns to chronic diseases. Despite the growing evidence of associations between dietary patterns and obesity, we are aware of no study that examined the association between patterns of nutrient intake and obesity.

OBJECTIVE

To identify major nutrient patterns in Iranian adults and investigate their association with general and abdominal obesity.

METHODS

In this cross-sectional study that was conducted under the framework of the Study on the Epidemiology of Psychological Alimentary Health and Nutrition (SEPAHAN), dietary data were collected using a validated dish-based 106-item semi-quantitative food frequency questionnaire in 8691 subjects aged 18-55 years. Complete data of 6724 and 5203 adults were available for general and abdominal obesity, respectively. Data on anthropometric measures were collected through a self-administered questionnaire. General obesity was defined as body mass index ≥ 30 kg/m(2), and abdominal obesity as waist circumference > 102 cm for men and >88 cm for women. Daily intakes of 38 nutrients and bioactive compounds were calculated for each participant. Factor analysis, followed by a varimax rotation, was applied to derive major nutrient patterns.

RESULTS

Three major nutrient patterns were identified: (1) The first pattern was high in fatty acids (including saturated, monounsaturated and polyunsaturated fatty acids), cholesterol, vitamin B12, vitamin E, zinc, choline, protein, pyridoxine, phosphorus and pantothenic acid; (2) the second pattern was high in thiamine, betaine, starch, folate, iron, selenium, niacin, calcium, and manganese; and (3) the third pattern was high in glucose, fructose, sucrose, vitamin C, potassium, total dietary fiber, copper and vitamin K. Men in the highest quintile of the second pattern were less likely to be generally obese in the fully adjusted model [odds ratio (OR) 0.39, 95 % confidence interval (CI) 0.20-0.76]. After adjustment for potential confounders, a significant positive association was observed between the third pattern and general obesity among men (OR 1.77, 95 % CI 1.04-3.04), but not women (OR 1.18, 95 % CI 0.74-1.88). No overall association was seen between patterns of nutrient intake and abdominal obesity in both genders.

CONCLUSIONS

Major nutrient patterns were significantly associated with general, but not abdominal obesity among male participants of the SEPAHAN study. Further studies in other populations, along with future prospective studies, are required to confirm these findings.