Male and female cats have different regional body compositions and energy requirements for weight loss and weight maintenance

Abstract

Body composition and energy requirements are different between males and females in several species, and both interfere with weight loss. The aim of this study was to compare the total and regional body composition and energy requirements in obese male (n = 8) and female (n = 8) cats, during weight loss and weight maintenance over 17 subsequent weeks after regimen. The total and regional (thoracic and pelvic limbs, and trunk) body composition was assessed by dual‐energy X‐ray absorptiometry (DXA). Females exhibited a higher fat mass (FM) than males (p < 0.05), and the trunk was the site with greater fat accumulation regardless of gender. A 23.0 ± 2.8% reduction in body weight was followed by a 50.3 ± 9.4% and a 37.0 ± 8.9% reduction in fat in the trunk region in males and females respectively. Lean mass (LM) mobilization was also increased in the trunk (p < 0.05), and the loss of LM was associated with a reduction in bone mass. The energy intake to achieve the same rate of weight loss was 12.9 ± 3.4% higher in males (p < 0.05). The cats exhibited a gradual increase in energy requirements to maintain their body weight after weight loss (p < 0.05). It was concluded that obese cats mainly accumulate fat in the trunk. The reduction in lean mass after the regimen also occurred in the trunk, with no modifications in the skeletal muscle mass of the limbs. Neutered male cats have higher energy requirements than neutered females, and gender should be considered during obesity management in cats.

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

“…Literature on the sex implications of EE is controversial in cats (19) . However, males showed an EE 14 % higher using the feeding trial method (23) and an EE 12 % higher using the DLW method (24) than that of females in previous publications, supporting the results of the current study.…”

“…In the current study, this gain in body weight was characterised by an increase in LM in all groups but also by an increase in FM in obese and non-obese females. Interestingly, the FM in kilograms of males did not change, highlighting differences in energy metabolism and substrate utilisation between the sexes that should be further explored (22)(23)(24) . However, despite the increase in LM, there was no improvement in cat BC, as the LM percentage did not change for F-OB, M-NO and M-OB groups fed the HP (55 % CP) diet; however, the LM percentage decreased in the F-NO group when fed this treatment due to the increase in FM.…”

“…The available equations for estimating energy requirements also do not account for the possible influence of sex, reproductive condition, BC, age and physical activity (19)(20)(21) . Higher LM and EE in males compared with females have been reported (22)(23)(24) . The increase in body fat content in overweight and obese cats is also associated with reduced EE for maintenance, limiting the amount of food intake by these cats and increasing their chance of gaining weight in ad libitum feeding systems (18,23,25) .…”

Validation of saliva and urine use and sampling time on the doubly labelled water method to measure energy expenditure, body composition and water turnover in male and female cats

“…In the present study, however, EE on a metabolic body weight basis was 14•2 % higher for males than for females. In a study that directly compared male with female cats during body weight loss and maintenance, male cats exhibited a general EE that was 12•3 % higher than that for females (5) . For several animal species, differences among sexes are recognised for energy requirements (53)(54)(55)(56) .…”

“…However, several other factors besides body composition may interfere with the energy expenditure (EE) of felines (2) . Male cats, for example, tend to be heavier, with more lean and less fatty mass than females, and may present higher EE (3)(4)(5) . Diet composition, neutering, genetics, physical activity, age and many other physiological and environmental factors also interfere with metabolic rate, thereby resulting in considerable differences in EE among individuals (6,7) .…”