A Low-Fat Diet but not Food Restriction Improves Lactational Performance in Obese Rats
Rats fed a high-fat diet before and during lactation have difficulty initiating lactation and have high pup mortality rates, low milk production and, consequently, poor pup growth. To determine if these adverse outcomes can be mitigated with dietary changes made after delivery, obese Sprague-Dawley rats (who had previously been fed a high-fat diet [AIN-93MTMmodified to contain 35% fat, w/w]) were assigned at parturition to continue to be fed this diet (HF) or switched to free access to a corresponding low-fat (LF) diet (AIN-93MTM4% fat w/w) or switched to the LF diet and restricted to consuming only 75% of ad libitum intake (LF/R). Dams lost weight during lactation, but weight loss was much less in the LF group (19 g) than in the other two groups (47 and 59 g, HF and LF/R, respectively). There was no appreciable change in body water; body fat decreased by about half in all groups, but most substantially in the LF/R group. Compared with the HF group, milk production was 50% higher in the LF group and 12% lower in the LF/R group. Milk lipid concentration tended to be higher and milk water concentration lower in the HF compared with the other two groups. Growth of the litters of the LF dams was significantly higher than both HF and LF/R dams. These results indicate that switching to a low-fat diet mitigates the negative effects of obesity and continued high-fat feeding on lactational performance and pup growth. Consumption of restricted quantities of a low-fat diet negatively affected milk production and failed to improve pup growth, despite the dams’ mobilization of body fat in support of lactation.
Unable to display preview. Download preview PDF.
- Agius L, Rolls BJ, Rowe EA, Williamson DF. Obese rats develop hyperketonemia and fatty liver during lactation. Int J Obes 1983;7:447–452.Google Scholar
- [IOM] Institute of Medicine, Subcommittee on Nutrition During Lactation, Committee on Nutritional Status During Pregnancy and Lactation, Food and Nutrition Board. Nutrition During Lactation. Washington DC: National Academy Press; 1991.Google Scholar
- Rolls BJ, Rowe EA, Fahrbach SE, Agius L, Williamson DE Obesity and high energy diets reduce survival and growth rates of rat pups. Proc Nutr Soc 1980;39:51A.Google Scholar
- Rolls BA, Edwards-Webb JD, Gurr MI. The influence of dietary obesity on milk composition in the rat. Proc Nutr Soc 1981;40:66A.Google Scholar
- Rolls BA, Barley JB, Gurr MI. The influence of dietary obesity on milk production in the rat. Proc Nutr Soc 1983;42:83A.Google Scholar