Background: Maternal nutrition is a pivotal factor in determining long-term energy homeostasis in the offspring. However, whether resveratrol (R), with antioxidant and anti-obesity actions, can improve the long-term impact of poor maternal nutrition on the physiological function of white adipose tissue in the offspring is unknown. We previously reported that maternal resveratrol intake during pregnancy and lactation has long-term effects on metabolism in the offspring and these effects depend on the type of diet ingested by the mother and on the offspring’s sex. Aim: Our aim was to further analyze whether resveratrol supplementation during pregnancy and lactation induces changes in visceral adipose tissue morphology in the adult offspring. Materials and Methods: Female Wistar rats received a low-fat diet (LFD; 3.8 Kcal/g, 10.2% fat) or a high fat diet (HFD; 5.1 Kcal/g, 61.6% fat) during pregnancy and lactation. Half of each group received resveratrol (R) in their drinking water (50 mg/L; intake 2.0-2.5 mg/Kg/day). Offspring were weighed at birth and then weaned onto standard chow on postnatal day (PND) 21. Body weight (BW) and energy intake (EI) were measured weekly until PND150 when they were sacrificed. The visceral adipose tissue (VAT) depot was weighed and histomorphometric analysis of hematoxylin and eosin-stained histological sections was conducted using image-processing software (Adiposoft-ImageJ). Data are expressed as mean ± SD (parametric analyses) or interquartile range (non-parametric analyses). Results: On PND150, male offspring from HFD dams weighed more and had more VAT than those from LFD dams (p<0.0001). Maternal R decreased BW in males from HFD mothers (p<0.01), but tended to increase it in offspring from LFD dams such that BW of males from LFDR dams was similar to that of males from HFD mothers. The amount of VAT paralleled the changes in BW. Offspring from HFD dams had higher accumulated EI than those from LFD dams (males: p<0.001; females: p<0.01), with maternal R decreasing it in males from HFD dams (p<0.001). R decreased the number of adipocytes/area in the offspring from LFD mothers, reaching statistical significance only in males (p<0.0001) and shifted the distribution of adipocyte size to a significantly higher incidence of large adipocytes regardless of sex or diet [males: LFD= 260.9 μm2 (227.4-286.2); LFR= 287.5 μm2 (258.9-314.2); HFD= 257.5 μm2 (236.3-279.7); HFR=266.4 μm2 (243.8-292.3). Females: LFD= 239.7 μm2 (222.7-258.8); LFR= 278.0 μm2 (252.7 - 317.9); HFD= 271.8 μm2 (233.6 -308.0); HFR= 316.6 μm2 (286.8- 349.0)]. In conclusion: 1. Maternal resveratrol intake during pregnancy and lactation modulates adipocyte morphology in the offspring. 2. The effect of resveratrol varies depending on the diet of the mother. 3. These effects are sex dependent. Unless otherwise noted, all abstracts presented at ENDO are embargoed until the date and time of presentation. For oral presentations, the abstracts are embargoed until the session begins. s presented at a news conference are embargoed until the date and time of the news conference. The Endocrine Society reserves the right to lift the embargo on specific abstracts that are selected for promotion prior to or during ENDO.