Fig. 2.

a Time course of plasma acyl ghrelin after 5-day MCT or 3-week MCT–ghrelin combination treatment. Changes in plasma acyl ghrelin were evaluated at 7:00 a.m., 10:00 a.m., 2:00 p.m., and 4:00 p.m. among treatments. Significant changes in the treatments (p = 0.0097), and in the sampling timings (p = 0.0003) are confirmed by a linear mixed effect model. ^**p < 0.01, ^***p < 0.001 between different timings or treatments, using the least squares means Tukey’s honestly significant difference test. Open square, pre-treatment; closed square, after 5-day intake of MCT with octanoic acid C 8:0 alone; closed triangle, after 3-week MCT–ghrelin combination treatment. b Comparison of the changes in the plasma acyl ghrelin and free FA 8:0 levels during the treatment course of a 5-day intake of MCT alone, followed by 3-week MCT–ghrelin combination treatment. Significant increases in the plasma levels of free FA 8:0, obtained at 10:00 a.m. (p < 0.0001) and acyl ghrelin (p = 0.0072), obtained at 4:00 p.m. are confirmed by a linear mixed effect model. ^†p < 0.05, ^††p < 0.01, ^††††p < 0.0001, compared with the pre-treatment values, using the least squares means Tukey’s honestly significant difference test. Continuous line, plasma acyl ghrelin; dashed line, free FA 8:0. Data are presented as means with standard error. FA fatty acid, MCT medium-chain triglyceride