Diet 7013

Sprague-Dawley rats (Charles River Laboratories, Hollister, CA) were housed in individual cages, exposed to 12-hour light-dark cycles at 21–23°C, and allowed ad libitum access to standard rat chow (Diet 7013, Envigo, Madison WI) [23 ]. The diet contained the following: energy 3.1 kcal/kg, (calories from protein 23%, from fat 18%, and from carbohydrate 59%), crude protein 18%, fat (ether extract) 6.2%, carbohydrate (available) 45%, crude fiber 4%, neutral detergent fiber 13.6%, and ash 6.2%. The National Institutes of Health guidelines were followed. All protocols were approved by the Animal Research Committee at the University of California, Los Angeles (protocol no. 1999-104-53E).

2 days prior to dietary treatment, mice were individually housed. Fasting for 24 hrs was accomplished by placing mice in a new cage without food (fasting arena) with ad libitum access to water. Refeeding entailed allowing fasted mice ad libitum access to either normal chow (Diet 7013, Envigo, Madison, WI; Supp. Fig. 1), LFD (D12450B, Research diets, New Brunswick, NJ; Supp. Fig.2) or HFD (D12492, Research Diets, New Brunswick, NJ; Supp. Fig. 3) for 2 hrs. For behavioral experiments, mice underwent the training phase for NOR or NLR prior to refeeding at 23.5 hrs of fasting. Food disappearance was measured as previously described [15 (link)]. In brief, food was placed in a dish inside the fasting arena and the reduction of weight of the dish + food before and after 2 hrs of refeeding was equated to food consumption. Mouse weight was recorded at the time points indicated using an Ohaus Adventurer Pro digital scale (Parsippany, NJ).

Pregnant Sprague-Dawley rats received ~50% of their daily food intake beginning from gestation day 11 through day 21, causing caloric restriction during mid- to late pregnancy (~11g/day), compared to their control counterparts who received ad libitum rat chow (~22g/d) (Diet 7013 from Envigo, Madison, WI: Energy 3.1 kcal/kg, [calories from protein 23%, from fat 18%, and from carbohydrate 59%] crude protein 18%, fat [ether extract] 6.2%, carbohydrate 45%, crude fiber 4%, neutral detergent fiber 13.6% and ash 6.2%). Both groups accessed drinking water ad libitum. At birth, the litter size was culled to six. Four groups were created by cross-fostering with control mothers (~40g/d) rearing control pups (CON) or prenatally growth restricted pups (IUGR), and pre- and postnatal growth restricted mothers (~20g/d) rearing prenatally growth restricted pups (IPGR) or control pups (PNGR) (Figure 1). At day 21, the female pups were examined soon after weaning from the mother.