Caloric restriction-induced weight loss with a high-fat diet does not fully recover visceral adipose tissue inflammation in previously obese C57BL/6 mice

Abstract

Caloric restriction (CR) reduces body weight and systemic inflammation, but effects on adipose tissue under dietary lipid overload are controversial. We evaluated the effects of CR-induced weight loss with a high-fat diet (HF) on adipose tissue inflammation of obese mice. Male mice were assigned into LF (low-fat diet) and HF. After 8-wk, HF was reassigned for another 7-wk into HF – kept at HF; LFAL - switched from HF to LF ad libitum; RHF - fed HF calorie-restricted to reach LFAL body weight. Serum markers, adipocytokines, morphology, and inflammatory infiltrates in retroperitoneal adipose tissue (RAT) were accessed. LFAL and RHF reduced body weights, equaling to LF. LFAL restored almost all inflammatory markers as LF, except tumor necrosis factor-alpha (TNF-α), monocyte chemoattractant protein-1 (MCP-1), and adiponectin. Compared to HF, RHF lowered visceral adiposity, retroperitoneal adipocyte sizes, RAT inflammatory cell infiltration as well as TNF-α, interleukin-6, hepatic and serum C-reactive protein, which were higher than LFAL; adiponectin and MCP-1 did not change. CR with high-fat diet reduced body weight and attenuated visceral adiposity, but did not fully recover visceral tissue inflammation.
 Novelty bullets
 • Caloric restriction in a high-fat diet ameliorated visceral adiposity.
 • Caloric restriction in a high-fat diet did not recover visceral adipose tissue inflammation.

Contribution of PGC-1α to Obesity- and Caloric Restriction-Related Physiological Changes in White Adipose Tissue

“…In this manuscript, we review findings mainly based on studies that focus on the physiological changes from normal conditions to obese or CR conditions. However, there are many studies that demonstrate CR-related changes in obese conditions [ 133 , 134 , 135 , 136 , 137 ]. Investigation of the effects of CR on obesity physiology is important for evaluating the clinical significance of CR.…”

Visceral Adiposity and Cancer: Role in Pathogenesis and Prognosis

“…These hypotheses take origins from the findings that calorie restriction (CR), a reduction in energy daily intake with maintained number and frequency of meals, delays age-related pathologies and increases lifespan. Intriguingly, the implementation of a CR approach in mice has been shown to stimulate browning in VAT, resulting in loss of weight and visceral adiposity mainly due to a decrease of adipocytes size, which dampens the inflammatory processes overall [213,214]. By contrast, a CR approach for 8 weeks in obese individuals results in a negative regulation of browning in SAT [215].…”