# Characteristics and correlation analysis of postprandial free fatty acids and cortisol levels in males after different meals: a clinical trial

## TL;DR

This study examines how different breakfast meals affect free fatty acids and cortisol levels in men, finding that high-fat meals significantly raise these levels and they are closely linked.

## Contribution

The study reveals a significant positive correlation between postprandial free fatty acids and cortisol levels after high-fat meals.

## Key findings

- High-fat meals caused FFA levels to rise above baseline, while other meals showed early suppression followed by a rebound.
- Cortisol levels after high-fat and fat meals showed an early decline followed by an increase, with significant correlations to FFA levels.
- The study found that increased dietary fat content leads to higher postprandial FFA levels.

## Abstract

Elevated levels of free fatty acids (FFA) and cortisol are linked to adverse metabolic effects. The changes in FFA and cortisol levels after different meals and their relationship are still not clear.

Eleven healthy male volunteers were recruited from Hebei General Hospital. Each participant consumed five different test meals, including high-fat meals, fat meals, protein meals, glucose meals, and fructose meals, with a one-week washout period between interventions. All test meals were consumed between 7:00 and 8:00 am. Blood samples were collected before and after each meal to assess blood lipids, blood glucose, insulin, FFA, and cortisol levels.

After consumption of the fat meals, FFA levels showed an initial rise followed by a gradual decline, peaking at 4 hours after the meal, and remaining above baseline at 6 hours (P < 0.001). In contrast, following the high-fat, protein, glucose, and fructose meals, FFA levels exhibited an early suppression with a subsequent rebound, reaching the lowest level at 2 hours after the meal. Among these meals, only after the high-fat meal did FFA levels rise above baseline (P = 0.003). After the high-fat and fat meals, cortisol levels declined early after the meal and then increased, with the lowest values observed at 4 and 2 hours, respectively. Following the protein and fructose meals, cortisol levels showed a continued decline over time. After the glucose meals, cortisol levels rose for a short time, peaked at 0.5 hours, and then decreased to below baseline value at 3 hours (P = 0.034). Significant positive correlation between cortisol and FFA levels were observed at 5 (r=0.610, P = 0.046) and 6 (r=0.824, P = 0.002) hours after the high-fat meals and at 3 (r=0.632, P = 0.037), 4 (r=0.673, P = 0.023), and 6 (r= 0.614, P = 0.045) hours after the fat meals.

As dietary fat content increases, postprandial FFA level also rises. The changes in FFA levels after consuming high-fat meals and fat meals for breakfast are closely related to the changes in serum cortisol.

https://www.chictr.org.cn, identifier ChiCTR2100048497.