Endocrine effects of a low-carbohydrate, high-fat ketogenic diet
Abstract
Low-carbohydrate, high-fat ketogenic diets (KD) have become popular in recent years and are often used in an effort to control body weight. Our laboratory examines how maintenance on a ketogenic diet affects the multiple peripheral and central neuroendocrine systems involved in the regulation of energy balance in rats. We have previously observed increases in epididymal fat pad weight, and plasma leptin and ghrelin concentrations, as well as decreases in plasma insulin concentrations following a 7-week KD. The present series of experiments explored the development of changes in plasma endocrine hormone profiles over the course of an 8-week KD and the endocrine effects of returning to a chow diet (CH) following 8 weeks of KD consumption. Rats were maintained on CH or KD and sacrificed after 1, 4, or 8 weeks of diet maintenance (Experiment 1). We found significant increases in epididymal fat pad weight only after the full duration of KD maintenance. Plasma leptin levels were also elevated in KD rats. Contrary to previous studies, the present experiment did not observe alterations in plasma insulin or ghrelin levels. In Experiment 2, rats were maintained on CH or KD for a total of 8 weeks. Following this time, KD rats were switched to consuming CH and sacrificed after 1, 4, or 8 weeks of CH feeding (9, 12, and 16 total weeks). Results were compared to data collected after 8 weeks of maintenance on the original assigned diet. We observed increases in caloric intake and plasma insulin concentrations following the switch from KD to CH, starting at weeks 14 and 16, respectively. Epididymal fat pad weights and plasma leptin concentrations remained at levels exhibited at the end of KD maintenance following the diet switch. The present series of experiments demonstrates the ability of KD to produce alterations in plasma endocrine hormones not only during diet maintenance, but also following the switch to an alternative diet.
Degree
M.S.
Advisors
Kinzig, Purdue University.
Subject Area
Psychobiology
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