High starch intake favours body weight control in neutered and spayed cats living in homes fed .

Different starch-to-protein ratios were compared among neutered and spayed domiciled cats. Male and female obese and non-obese cats were fed kibble diets for 4 months high in starch (HS (38 % crude protein (CP)): starch 32 %, protein 38 %; DM basis) or high in protein (HP (55 % CP): starch 19 %, protein 55 %) but similar in energy and fat in a crossover design. Physical activity was evaluated using an accelerometer, and body composition (BC), energy expenditure (EE) and water turnover (WT) using the doubly labelled water method. Results were compared in a 2 diet × 2 sex × 2 body condition factorial arrangement. Cats fed the HS (38 % CP) diet maintained a constant body weight, but lean mass (LM) tended to be reduced in female obese but to be increased in male non-obese ( < 0·08) and increased in female non-obese cats ( = 0·01). The HP (55 % CP) diet induced an increase in cat body weight and LM ( < 0·05) without altering BC proportion. EE tended to be higher in males (351 (se 8) kJ/kg/d) than females (330 (se 8) kJ/kg/d; P = 0·06), was unaffected by diet or BC, decreased as age increased ( 0·44; < 0·01) and increased as physical activity increased ( 0·58; < 001). WT was higher for the HP (55 % CP) diet ( < 001) and increased with EE ( 0·65; < 001). The HS (38 % CP) diet favoured body weight control during 4 months of feeding. Caution is necessary to balance protein in diets of female obese cats over 5 years, as they may have low energy and food intake, with LM loss.