Background/Objective: Long-term weight loss (WL) maintenance is the biggest challenge for overweight and obesity due to the almost unavoidable phenomenon of partial or even total weight regain (WR) after WL. In the current study we investigated the relations of (the changes of) adipocyte size and other risk biomarkers with WR during the follow up of the Yoyo dietary intervention.

Design: In this randomized controlled study, 48 overweight/obese participants underwent a (very) low calorie diet to lose weight, followed by a weight stable period of 4 weeks and a follow-up period of 9 months. Anthropometric measurements, adipocyte volume of abdominal subcutaneous adipose tissue and plasma metabolic parameters (FFA, TG, total cholesterol, glucose, insulin, HOMA-IR, IL6, ACE activity, RBP4) at the beginning and the end of the follow-up were analyzed.

Results: Our results show that changes of TG, IL6, HOMA-IR and ACE are significantly positively correlated with WR. Multiple linear regression analysis shows that only the changes of TG and IL6 remained significantly correlated with WR and increased body fat mass. Moreover, the change of HOMA-IR was tightly correlated with the change in TG. Surprisingly, the change of adipocyte volume during follow up was not correlated with WR nor with other factors, but positive correlations between adipocyte volume and HOMA-IR were found at the beginning and end of the follow up.

Conclusions: These results suggest that TG and IL6 are independently linked to WR via separate mechanisms, and that HOMA-IR and adipocyte volume may indirectly link to WR through the change of plasma TG.