The Clinical and Metabolic Effects of Rapid Weight Loss in Obese Pet Cats and the Influence of Supplemental Oral L‐Carnitine

Abstract

The efficacy, safety, and metabolic consequences of rapid weight loss in privately owned obese cats by means of a canned weight-reduction diet and the influence of orally administered L-carnitine on rate of weight loss, routine clinical evaluations, hepatic ultrasonography, plasma amino acid profiles, and carnitine analytes were evaluated. A double-blinded placebo-controlled design was used with cats randomly divided into 2 groups: Group 1 (n = 14) received L-carnitine (250 mg PO q24h) in aqueous solution and group 2 (n = 10) received an identical-appearing water placebo. Median obesity (body condition scores and percentage ideal body weight) in each group was 25%. Caloric intake was restricted to 60% of maintenance energy requirements (60 kcal/kg) for targeted ideal weight. The reducing formula was readily accepted by all cats. Significant weight loss was achieved by week 18 in each group without adverse effects (group 1 = 23.7%, group 2 = 19.6%). Cats receiving carnitine lost weight at a significantly faster rate (P < .05). Significant increases in carnitine values developed in each group (P < .02). However, significantly higher concentrations of all carnitine moieties and a greater percentage of acetylcarnitine developed in cats of group 1 (P < .01). The dietary formula and described reducing strategy can safely achieve a 20% weight reduction within 18 weeks in obese cats. An aqueous solution of L-carnitine (250 mg PO q12h) was at least partially absorbed, was nontoxic, and significantly increased plasma carnitine analyte concentrations as well as rate of weight loss.

Improvement in insulin resistance and favourable changes in plasma inflammatory adipokines after weight loss associated with two months’ consumption of a combination of bioactive food ingredients in overweight subjects

“…Carnitine is an integral component in the transportation of long-chain fatty acids within the mitochondria for oxidation [36]. Supplemental carnitine has been shown to increase weight loss in animals [37] and to increase the oxidation of long-chain fatty acids in adults [38, 39].…”

Ontogeny and kinetics of carnitine palmitoyltransferase in liver and skeletal muscle of the domestic felid ()

“…Beyond supplementation of carnitine in support of normal growth and development, recent studies on hepatic lipidosis in felids have shown some favorable response to supplemental carnitine [37][38][39]. The mechanisms underly- ing this disorder likely involve increased fatty acid transport to the liver, increased triacylglycerol synthesis, decreased fatty acid oxidation and decreased release of very low density lipoprotein from the liver [40,41].…”

Effect of <i>L</i>-Carnitine on Weight Loss and Body Composition of Rats Fed a Hypocaloric Diet

“…The authors concluded from this that carnitine might modify the hormone metabolism as well [11]. There are some studies in obese cats and dogs which showed that dietary L-carnitine treatment during energy restriction enhances body weight loss [13][14][15]. We wanted to find out whether L-carnitine supplementation enhances the process of weight reduction also in species other than dogs and cats.…”

“…McCarthy [12] postulates that adding carnitine to a lowfat diet can enhance the weight loss effect. A small number of studies exists which proved beneficial effects of Lcarnitine supplementation on body weight loss, body composition and some metabolic parameters during calorie restriction; these studies, however, are limited to obese cats and dogs [13][14][15][16][17]. We intended to investigate whether beneficial effects of L-carnitine supplementation during energy restriction occur also in other species.…”