Fasting And Refeeding Cycles Alter Subcutaneous White Depot Growth Dynamics And The Morphology Of Brown Adipose Tissue In Female Rats

Intermittent food restriction (IFR) is used mainly for weight loss; however, its effects on adipose tissue are not known when alternating with an obesogenic diet. To demonstrate its effects on morphological dynamics of fat deposits, female Wistar rats were distributed into groups: standard control (ST-C), with commercial diet; DIO control (DIO-C), with a diet that induces obesity (DIO) during the first and last 15 d, replaced by a standard diet for thirty intermediate days; standard restricted (ST-R), with standard diet during the first and last 15 d, with six cycles of IFR at 50 % of ST-C; and DIO restricted (DIO-R), in DIO during the first and last 15 d, with six cycles of IFR at 50 % of DIO-C. At 105 d of life, white adipose tissue (WAT) and brown adipose tissue (BAT) deposits were collected, weighed and histology performed. The DIO-R group showed higher total food intake (DIO-R 10 768 center dot 0 (SEM 357 center dot 52) kJ/g v. DIO-C 8868 center dot 6 (SEM 249 center dot 25) kJ/g, P < 0 center dot 0001), energy efficiency during RAI (DIO-R 2 center dot 26 (SEM 0 center dot 05) g/kJ v. DIO-C 0 center dot 70 (SEM 0 center dot 03) g/kJ, P < 0 center dot 0001) and WAT (DIO-R 5 center dot 65 (SEM 0 center dot 30) g/100 g v. DIO-C 4 center dot 56 (SEM 0 center dot 30) g/100 g) than their respective control. Furthermore, IFR groups presented hypertrophy of WAT and BAT, as well as fibrosis in BAT. Thus, IFR can establish prospective resistance to weight loss by favouring changes in adipose tissue morphology, increased energy intake and efficiency. Finally, the DIO diet before and after IFR aggravates the damages caused by the restriction.