SYMPATHETIC ACTIVITY IS LOWER IN RATS FED A BEEF TALLOW DIET THAN IN RATS FED A SAFFLOWER OIL DIET

Effects of dietary fats consisting of different fatty acids on sympath etic activity and body fat accumulation were studied in rats. Rats wer e meal fed an isoenergetic diet based on either beef tallow or safflow er oil for 8 weeks. Carcass fat content was greater (P < .05) in rats fed the beef tallow diet than in rats fed the safflower oil diet. Nore pinephrine (NE) turnover rate was significantly lower (P < .05) in int erscapular brown adipose tissue (IBAT) and pancreas in rats fed the be ef tallow diet than in rats fed the safflower oil diet, resulting in a decreased (P < .05) diet-induced thermogenesis (DIT) and an increased (P < .05) serum insulin concentration in the former. To confirm the e ffects of dietary fats on sympathetic activity in relation to body fat accumulation, rats were chemically sympathectomized. Sympathectomy ab olished the differences in body fat accumulation, DIT, and serum insul in concentration between the two dietary groups. These results suggest that the beef tallow diet promotes body fat accumulation by reducing sympathetic activity as compared with intake of the safflower oil diet . Copyright (C) 1995 by W.B. Saunders Company