Lower Dietary Energy Density Research Articles

Influence of Pregnancy, Lactation, Litter Size and Diet Energy Density on the Pancreas of Sows

In a first experiment, each of 52 sows having raised one litter was randomly assigned to one of the five following groups: control (nongravid) for pregnancy (CP), 110 d pregnancy (P110), control (nongravid) for lactation (CL), 4 wk lactation with 8 (L8) and with 12 (L12) piglets. In a second experiment, each of 36 sows having raised three litters was randomly assigned to the following groups: control group (nongravid) fed a low energy density 1% tallow diet (CLED) and two lactation groups, one fed the low energy density diet (LLED) and the other fed a high energy density 10% tallow diet (LHED). At slaughter the pancreas was excised, freed from fat and weighed. Fragments were homogenized for evaluation of protein, amylase, chymotrypsin, RNA and DNA content. Pancreas weight was not affected by pregnancy, lactation or litter size. Pancreatic cellular mass (15.2%), amylase (42.6%) and chymotrypsin (34.6%) concentrations were smaller among pregnant sows (P110) than among their controls (CP). Amylase concentration tended to be lower among the L12 than among the L8 sows (P=0.067). Sows fed the high energy diet (LHED) had greater pancreas weight (15.3) and chymotrypsin activity (48.1%) than those fed the low energy diet (LLED). Pregnancy, lactation, litter size and dietary energy density during lactation all had a significant effect on the pancreas of the sow.

The effects of high and low energy density diets on satiety, energy intake, and eating time of obese and nonobese subjects

The concept of time-energy displacement is based on the hypothesis that unrefined complex carbohydrates of low energy density will prolong eating time and induce satiety at a low energy intake. The present study compared the effects of diets low in energy density and high in energy density on satiety, energy intake, and eating time among 20 obese and nonobese subjects. Each diet was served over a 5-day period, and subjects were allowed to eat to satiety. With equal acceptance ratings of the diets, satiety was reached on the diet low in energy density at a mean daily energy intake one-half that of the diet high in energy density (1570 versus 3000 kcal). Eating time was significantly longer on the diet low in energy density by an average of 33%/day. Obese and nonobese subjects were comparable in their satiety ratings, energy consumption, eating time, and food acceptance. These data support the concept of time-energy displacement, which should therefore have applicability to the treatment and prevention of obesity.