Efficiency of utilization of various sources of energy for growth.

Abstract

The relative efficiency of dietary sucrose, protein sources, and fats in depositing body protein and fat (total energy) was directly estimated in young rats by feeding graded levels of each as supplements to a fixed amount of a basal diet that was presumably adequate in all essential nutrients except for energy. Under these conditions, the net gain in total body energy was a linear function of the amount of supplement added and the data fulfill the criteria of a valid slope-ratio bioassay. The available energy measured by this technique for sucrose and protein were similar, as would be expected. Dietary Rice et al. (9) and that the available energy from dietary fat under these conditions compared to sucrose is substantially larger than predicted from the Atwater values. METHODSThe design of the four experiments reported was similar to that proposed by Rice et al. (9). The three basal diets used (Table 1) were formulated to provide all of the essential nutrients when fed in limiting amounts, so the added energy supplement would be the only variable to affect the rates of weight gain and change in body composition. The weanling male rats of the Charles River strain (Charles River Breeding Laboratories) used in the four experiments received daily 5 g of one of the basal diets to which a fixed amount of the energy supplement under study was added.In each experiment, groups of animals received graded levels of sucrose. The response of these animals was compared to those that received fat (Spry, Lever Brothers), casein (General Biochemicals), or gluten (General Biochemicals). The amounts of the various supplements provided in the four different experiments are shown in the tables.After the weanling rats were received in the laboratory, they were fed a laboratory rat chow for 3 days and 5 g of the basal diet for the next 3 days. They were then divided into groups of similar mean weight. Each group in experiments 1 and 2 contained five animals; there were four animals per group in experiments 3 and 4. In each experiment, one group of animals was killed for analysis of body composition. The remaining animals received the appropriate diet for 21 days and were then killed for analysis. § The animals were housed in raised individual cages, kept at a constant temperature and humidity, and weighed two or three times weekly. Papers were placed under the cages so that any spilled food could be weighed and an equivalent amount added to the diet in the next few days. Fortunately, spillage was insignificant.When the animals were killed, the stomach and cecum were removed and discarded to avoid residual food, and the

High sucrose consumption promotes obesity whereas its low consumption induces oxidative stress in Drosophila melanogaster

“…The caloric values of diets were calculated by counting calories derived from sucrose and yeast. Sucrose caloric value 4 kcal/g was used for calculations (Donato, 1987). The caloric value of yeast was 1.17 kcal/g accordingly to the manufacturer's annotation.…”

The effects of beta-adrenergic blockade on body composition in free-fed and diet-restricted rats.

“…This indicates that the overall control of meta bolic pathways rather than the caloric intake alone de termines the percentage body fat in the growing rat. As has been reported by Donato and Hegstad [8], lipo genesis is not necessarily decreased under reduced calo ric intake in the growing rat. Furthermore, they [8] have indicated that even when total caloric intake is restricted, there is a direct deposition of a considerable portion of dietary fat to body fat.…”

“…As has been reported by Donato and Hegstad [8], lipo genesis is not necessarily decreased under reduced calo ric intake in the growing rat. Furthermore, they [8] have indicated that even when total caloric intake is restricted, there is a direct deposition of a considerable portion of dietary fat to body fat. This may be the case in obese patients who fail to maintain a lower body fat content under dietary restriction.…”

Effect of Low-Fat and/or Low-Energy Diets on Anthropometric Measures in Participants of the Women’s Diet Study

“…There is evidence that the Attwater values of 9 kcal/g for fat and 4 kcal/g for carbohydrate may not correspond to their metabolic energy yields. Based on body fat and protein deposition in young rats, metabolic energy yield was found to be greater than expected using graded levels of dietary fat or, conversely, lower than expected using graded levels of dietary carbohydrate [40]. Human metabolism may differ, but the possibility exists that seemingly iso-energetic substitution of carbohydrate for fat may in reality result in an energy deficit.…”