Exercise, dietary obesity, and growth in the rat.
Four regimens: high-fat diet, exercised (I); chow, exercised (II); high-fat sedentary (III); and chow, sedentary (IV) were initiated in 35-day-old male rats. Growth was exponential in I and II and exponential progressing to rectilinear in III and IV. The exponential model predicted the decreasing rank order in asymptotic weight to be: III, IV, I, II. Body composition data (9 components) showed rank order in masses of fat and the fat-free body mass compartment (FFBM) to be the same as for asymptotic live weight. The rectilinear growth mode probably reflected fat accretion. High-fat diet increased and treadmill exercise decreased FFBM, the latter being reversible. These effects depended on regimen initiations by the 5-7th wk of age. During growth, masses of H2O, muscle, and skin increased as functions of body size; bone as a function of age; and heart, liver, gut, testevity, and diet. Growth in body size was expressed more precisely with FFBM, instead of live weight, as the index of size.
D000311:Adrenal Glands / Q000378:metabolism; D000367:Age Factors; D000818:Animals; D001835:Body Weight; D001842:Bone and Bones / Q000378:metabolism; D002490:Central Nervous System / Q000378:metabolism; D004041:Dietary Fats; D007413:Intestinal Mucosa / Q000378:metabolism; D050356:Lipid Metabolism; D008099:Liver / Q000378:metabolism; D008297:Male; D009132:Muscles / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism; D009765:Obesity; D005082:Physical Exertion; D051381:Rats / Q000254:growth & development*; D012867:Skin / Q000378:metabolism; D013737:Testis / Q000378:metabolism
D004041:Dietary Fats