Isocaloric Substitution of Dietary Carbohydrate Intake with Fat Intake and MRI-Determined Total Volumes of Visceral, Subcutaneous and Hepatic Fat Content in Middle-Aged Adults.

Christa Meisinger,Jakob Linseisen,Christopher L Schlett,Susanne Rospleszcz,Elke Wintermeyer,Annette Peters,Barbara Thorand,Fabian Bamberg,Roberto Lorbeer

doi:10.3390/nu11051151

Abstract

The present study investigated the association of carbohydrate intake and isocaloric substitution with different types of fat with visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT) and hepatic fat content as determined by magnetic resonance imaging (MRI). Data from 283 participants (mean age 56.1 ± 9.0 years) from the MRI sub study of the KORA FF4 study were included. VAT, SAT and total body fat were quantified by a volume-interpolated VIBE-T1w-Dixon MR sequence. Hepatic fat content was determined as the proton density fat-fraction (PDFF) derived from multiecho-T1w MR sequence. Dietary intake was estimated using information provided by two different instruments, that is, repeated 24-h food lists and a food frequency questionnaire. Replacing total carbohydrates with an isoenergetic amount of total fat was significantly positively associated with VAT and hepatic fat, while there was no significant association with SAT. The multivariable adjusted β-coefficient for replacing 5% of total energy (5E%) carbohydrates with total fat was 0.42 L (95% CI: 0.04, 0.79) for VAT. A substitution in total fat intake by 5E% was associated with a significant increase in liver fat content by 23% (p-value 0.004). If reproduced in prospective studies, such findings would strongly argue for limiting dietary fat intake.

Highlights

IntroductionWeight gain and a subsequent increase of body fat content causes an enlargement of adipocytes and goes along with an increase of subcutaneous fat and of fat depots in other parts of the body
Obesity, a worldwide epidemic due to the availability of many unhealthy food options and limited physical exercise [1], is a known risk factor for many metabolic disorders like coronary heart disease, malignancies, osteoarthritis and respiratory disorders [2].Weight gain and a subsequent increase of body fat content causes an enlargement of adipocytes and goes along with an increase of subcutaneous fat and of fat depots in other parts of the body
Replacing total carbohydrates with an isoenergetic amount of total fat was significantly positively associated with visceral adipose tissue (VAT) and hepatic fat, while there was no significant association with subcutaneous adipose tissue (SAT) (Table 3)

Summary

Introduction

Weight gain and a subsequent increase of body fat content causes an enlargement of adipocytes and goes along with an increase of subcutaneous fat and of fat depots in other parts of the body. This ectopic fat is mainly stored intra-abdominally and in muscle tissue, the liver and in the beta cells. Both subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) are metabolically active, the excess accumulation of VAT appears to play a more significant pathogenic role. The contribution of carbohydrates from whole grain consumption to total carbohydrate intake decreased while the intake of refined starchy products and sugar-containing food increased [6,7]

Methods

Results

Conclusion