Modelling 16/8 intermittent fasting and breakfast-skipping in mouse adipocytes 3T3-L1 in vitro: a transcriptomics study

Background: Obesity, a chronic metabolic disease, lacks effective treatments. Intermittent fasting (IF), especially time-restricted feeding (TRF), shows promise, yet the comparative molecular effects of different regimens remain unclear. This study examined their impact on 3T3-L1 adipocytes and transcriptomic changes. Methods: 3T3-L1 cells were differentiated into adipocytes for 7 d and synchronized with 200 nM dexamethasone before 24 h treatments: (1) Control [high glucose (4.5 g/L DMEM), 15 % bovine calf serum (BCS)], (2) 16 h fasting/8h feeding IF [control medium ZT3–ZT11; low glucose (1.0 g/L) and low serum (1 % BCS) ZT12–ZT2], (3) “Distributed” IF [medium glucose (2.75 g/L), medium serum (8 % BCS) ZT0–ZT24], (4) Breakfast-skipping (BS) [low glucose/low serum ZT1–ZT5; control medium ZT6–ZT0]. Lipid accumulation was assessed by Oil Red O staining; whole transcriptome sequencing was performed. Results: The 16/8 IF regimen produced the greatest lipid reduction (74.41 % vs. control; p = 0.007) with upregulation of lipolysis genes (Tgm2, Notch2) and downregulation of adipogenesis and glycolysis genes (Ccnd1, Ldha). Pathway enrichment included TGF-β, p53, and apelin signaling. In contrast, the BS regimen did not differ significantly in lipid accumulation compared to control (p = 0.999), but nevertheless showed downregulation of mitochondrial genes mt-Rnr1 and mt-Rnr2. Conclusion: This work highlights the novel comparative evaluation of IF/TRF regimens in adipocytes using transcriptomics, demonstrating that 16/8 IF most effectively reduced lipid content and modulated metabolic pathways within 24 h. These findings provide mechanistic insight that strengthens the rationale for TRF as a dietary approach for obesity management.