Regulation of food intake during growth in fatty and lean female Zucker rats given diets of different protein content
Open Access
- 1 November 1976
- journal article
- research article
- Published by Cambridge University Press (CUP) in British Journal of Nutrition
- Vol. 36 (3), 457-469
- https://doi.org/10.1079/bjn19760100
Abstract
1. Food intake, and the rates of protein, lipid and energy deposition during growth were measured for lean and congenitally obese (fatty) female Zucker rats given diets of different protein content ad lib. Six semi-synthetic diets were used, which contained 40, 100, 150, 300, 500 and 700 g casein/kg (diets 40C, 100C, 150C, 300C, 500C and 700C).2. Dietary treatments began when the rats were 34 or 35 d old. Collections of urine and faeces were analysed for energy content. The total carcasses of all the rats were analysed individually for protein, lipid and energy.3. In the first experiment, twelve rats of each phenotype were given diets 150C or 300C. Four fatty and four lean rats were killed at 50, 66 and 98 d of age. In the second experiment groups of four fatty and four lean rats were given diets 40C, 100C, 500C and 700C ad lib. until they were killed at 66 d of age. Other groups of fatty rats were pair-fed from 35 to 67 d of age on diets 100C and 500C. Rats were also killed at 24 and 34 d of age to provide initial samples for the comparative slaughter procedure.4. When given food ad lib., fatty and lean rats had identical rates of protein deposition at all ages and for all diets, but lipid and energy deposition were always much greater in the fatty rats. Food intake was also much greater for the fatty rats (except on diet 40C). Differences in food intake and growth rate attributable to diet were most pronounced for the range of diets 40C-150C.5. Fatty rats pair-fed to lean rats deposited less protein but about twice as much energy and lipid as lean rats on the same diets.6. The results are discussed in relation to existing theories of appetite control. It appears that food intake is precisely regulated in the congenitally obese Zucker rat. This regulation is intimately linked with the impetus for protein deposition and the rates of retention of lipid and energy appear to be of no importance in relation to appetite control.This publication has 14 references indexed in Scilit:
- Efficiency of Energy Utilization by the Zucker Hereditarily Obese Rat "Fatty"Experimental Biology and Medicine, 1975
- Heat loss and energy retention during growth in congenitally obese and lean ratsBritish Journal of Nutrition, 1974
- Genetic obesity in rats. I. The effects of food restriction on body composition and hypothalamic functionMetabolism, 1973
- A rapid method for the accurate determination of lipid in animal tissuesThe Analyst, 1972
- The use of automation in determining nitrogen by the Kjeldahl method, with final calculations by computerThe Analyst, 1970
- Weight regulation in normal and hypothalamic hyperphagic rats.Journal of Comparative and Physiological Psychology, 1966
- FATTY, A NEW MUTATION IN THE RATJournal of Heredity, 1961
- Factors influencing food intake of rats fed low-protein rationsAmerican Journal of Physiology-Legacy Content, 1959
- Interactions of Dietary Fiber and Protein on Food Intake and Body Composition of Growing RatsAmerican Journal of Physiology-Legacy Content, 1958
- REGULATION OF ENERGY INTAKE AND THE BODY WEIGHT: THE GLUCOSTATIC THEORY AND THE LIPOSTATIC HYPOTHESISAnnals of the New York Academy of Sciences, 1955