Energy Restriction Results in a Mass-Adjusted Decrease in Energy Expenditure in Cats That Is Maintained after Weight Regain ,

Abstract

Dietary energy restriction (ER) is used to treat obesity in cats but it is often unsuccessful. The purpose of this study was to determine whether ER results in a sustained decrease in mass-adjusted energy expenditure (EE) that may oppose weight loss and promote weight regain. EE and body composition were measured in 10 adult neutered cats at 3 time points: baseline (obese cats), during weight loss (40% ER), and following weight regain. The cats started with a body weight (BW) of 6.1 ± 0.30 kg, body condition score (BCS) of 7.6 ± 0.14 (on a 9-point scale), and fat body mass (FM) of 38 ± 1.0% of BW. After weight loss, BW was 5.0 ± 0.19 kg, BCS was 5.5 ± 0.07 kg, and FM was 31 ± 1.6% (P < 0.01). After weight regain, BW was 6.2 ± 0.30 kg, BCS was 7.7 ± 0.16, and FM was 42 ± 1.8% (P < 0.01). Total EE decreased from 1258 ± 33.7 kJ/d to 1025 ± 39.6 kJ/d during weight loss (P < 0.001). After weight regain, EE was still lower than baseline (1103 ± 41.5 kJ/d, P < 0.001). Energy intake (EI) at baseline (1337 ± 50.6 kJ/d) was higher than EI after weight loss and regain (1217 ± 61.2 kJ/d), resulting in no differences in energy balance (78 ± 30.4 and 104 ± 35.4 kJ/d, respectively, P = 0.581). These results support the hypothesis that ER results in a mass-adjusted decrease in EE in cats that is maintained after weight regain.