<qa>  What is the aim of the secondary companion pilot study?In this the preliminary phase, a total of 12 obese patients who have been accepted to undergo gastric restrictive surgery will be recruited. Although the inclusion criteria for the secondary companion pilot study include diabetic patients, having diabetes mellitus is not necessary for the testing of the hypothesis in the preliminary phase. The aim is to test whether subcutaneous adipose tissue in the abdominal region is similar to visceral and omental adipose tissue in terms of cellular mechanisms after ingestion of MCT oil. 