Cats are obligate carnivores. This statement is news to no one, and yet we often don't recognize the importance of that statement
or feed them accordingly. While cats can use carbohydrates (CHO) as a source of metabolic energy, they have no requirement
for them (nor do dogs for that matter). But, more importantly, because cats evolved consuming prey (e.g. high protein, low
to moderate fat, minimal carbohydrate), they are metabolically adapted for higher protein metabolism and lower CHO utilization.
What does that mean metabolically and nutritionally? There are a number of specific metabolic and biochemical differences
in feline physiology that are important. For those who are interested in the specific details of these metabolic and physiologic
differences in the nutritional biochemistry of cats, the reader is referred to several recent reviews on this subject. This
paper will discuss several important medical problems in cats that may be directly linked to, or may be specifically managed
by, dietary manipulation.
The primary reason for development of obesity in any animal is that they are consuming more energy than they are expending.
This can occur when a cat has excessive dietary intake of calories (food or treats) or when there is a reduction in energy
expenditure (reduced activity, illness or injury resulting in less exercise, etc). In indoor cats, reduced energy expenditure
is a very important problem, and this is compounded by the fact that it is not easy to increase energy expenditure in cats
like dogs with directed exercise. Additionally, because many cat owners prefer to feed free choice dry food, the risk of overfeeding,
even in very small amounts is very high. In either case, the primary reason that weight gain occurs in cats is that they have
a positive energy balance and this must be changed to affect weight loss. In both dogs and cats, neutering is an important
risk factor due to the hormonal changes that occur that result in changes in levels of leptin, progestins, and other hormones
that result in increased appetite, and reduced energy metabolism and metabolic rate. The key factors for prevention of obesity
in neutered animals appears to be careful control of intake immediately after neutering (no free choice feeding, reduction
of intake by 25% to account for the hormonal changes resulting in reduced energy needs), and close monitoring of body weight
and BCS to allow adjustments in intake if needed. In addition, because feeding our cats is a social interaction, feeding and
food interaction with the cat can become a daily social interaction that can become a problem resulting in overfeeding and
inappropriate food intake patterns. It has been shown that in households where the owners are health conscious (conscious
of diet and nutrition, who exercise regularly, and watch their own weight) they tend not to have obese pets (except where
free choice feeding is used). Thus, there are clearly human behavioral and "food is love" issues that have to be considered
in the development of obesity, and these must be addressed for successful weight control to be achieved.