The treatment and prevention of overweight and obesity in cats is based on our understanding of the basic nutritional needs of cats and their eating behavior.
In fact, the way we actually feed cats and the food we actually feed them are often contrary to the “ideal way of feeding cats and food”. Indoor cats usually consume dry food (high energy, high carbohydrates) freely, and the energy provided by dry food often exceeds the standard (beyond the actual needs of the cat). For outdoor cats, they must keep their bodies healthy and thin in the wild in order to successfully forage.
For indoor cats, they are accustomed to sedentary sitting, ready-made food, and lack of a lot of physical activity, so they do not need the same physical conditions as wild cats. Like other species, free intake of dry food and lack of exercise are the main culprits for obesity or overweight in indoor cats.
Obesity and diet
In the development and treatment of obesity, the role of carbohydrates in the diet is a factor that has to be considered. This is not because there is a direct connection between carbohydrates and fats (carbohydrates are stored as fats), but because of the effect of carbohydrates on protein levels in the diet.
Carbon water and fat conversion
The higher the concentration of carbohydrates in the diet, the lower the protein intake, which is lower than the requirement. We should never forget that cats were designed to preferentially use protein and fat as energy sources during evolution, and cats do not need any carbohydrates in their diet.
Cats need protein as a source of energy for metabolism. Therefore, a diet with insufficient protein content will cause a decrease in muscle mass or symptoms of muscle wasting when the digestibility is maintained at an average value (the body will consume its own protein reserves as a source of nutrition and energy ). The decrease in net muscle content will result in a lower metabolic rate, thereby exacerbating weight gain.
Weight loss food can cause muscle atrophy
Traditional weight loss programs include feeding energy-restricted foods with features of low-fat, low-protein, high-carbohydrate, and high-fiber diets. However, although these diets may cause cats to lose weight, they have an adverse effect on their health, because the nature of cats’ consumption of protein as the primary energy source will not change. A truly successful weight loss program is to reduce the amount of fat in the cat’s body while maintaining a lean body mass.
We must remember that lean body mass is the driving force of basal energy metabolism. Loss of fat-free body mass is the main reason for weight rebound because appetite is not reduced and satiety is not achieved.
A high-protein, low-carbohydrate diet is the best choice
Several recent studies have evaluated the use of high-protein, low-carbohydrate diets (protein content of 45% or higher) to reduce cat weight. In these studies, cats lost weight while maintaining their lean body mass.
Importantly, high-protein, low-carbohydrate canned food not only keeps these cats’ weight loss continuously but also helps to reduce the cat’s desire to eat without interruption. This is simply because the cat’s appetite is more easily satisfied when fed canned or raw meat foods than when fed dry foods containing fiber.
Dry food must be extruded at high temperatures to form “small biscuits”, so carbohydrates must be added during the cooking process. Therefore, it is difficult for dry food to meet the low-carbohydrate content requirements. In addition, many of the high-protein and low-carbohydrate dry foods that are available are not low-calorie foods, so it is very easy to cause cats to consume too many calories, including too many protein calories, which can also cause cats to gain weight or lose weight.
In this case, the best commercial diet that can achieve high protein, low carbohydrate, and controlled calorie intake is non-canned food or a nutritionally balanced raw meat diet. But remember, even if you are feeding canned food, it does not mean that you are feeding high-protein, low-carbohydrate food — you have to read the product label to get the right information, and it does not mean the food you are feeding belongs to high-quality protein.
Stop ad libitum
An important part of weight loss is to remember that all diets are counted in calories. Even if they are fed a high-protein, low-carbohydrate diet, most indoor cats, cannot “ad liberate” because if they consume too many calories, they will become fat or remain obese.
The food distributed to cats every day should be composed of a variety of small amounts of food to mimic the cat’s natural eating strategy, that is, hunting and catching about 10 small prey per day. This also increases the thermal effect of food, increases the metabolic rate, and helps cats lose weight.
Calorie calculation for weight loss
A key point for obesity prevention or treatment is how to balance the equations of energy intake and energy expenditure. For indoor cats, due to lifestyle reasons, the amount of exercise is reduced, and limiting energy intake has become the most important point for preventing or treating obesity. Most indoor cats do not need food that exceeds their resting energy requirements, namely RER, to meet their daily nutritional needs.
For a cat weighing about 5 kg, its resting energy requirement is about 180-200 kcal/day. Especially obese cats may need to reduce their intake by 20% to 40%, or only consume 60-80% of RER to achieve the goal of weight loss. Therefore, for a cat with a weight of about 7.5 kg and a target weight of 5 kg, it may be necessary to reduce the caloric intake to 120-130 kcal per day.
The key is to set a target calorie intake and ensure that you are fed high-protein food to maintain the cat’s body muscle mass and prevent protein malnutrition. Weigh the cat every month and adjust the amount of food according to the situation.
Write at the end
Low-fat, high-fiber diets can achieve the goal of energy restriction, but most of the protein content in these diets is not enough to maintain muscle mass. This loss of muscle mass will lead to unhealthy weight loss and a tendency to violently rebound, that is, the loss of muscle mass will always lead to rapid weight gain again.
High-protein, low-carbohydrate, and low-fat diets are ideal for cats to lose weight: they help maintain muscle mass while limiting energy sources to reduce fat. However, partial control is the ultimate key to controlling energy intake.
The easiest way to feed a high-protein, low-carbohydrate diet while achieving partial control is to feed canned food or a complete raw meat diet with supplements. For cats that do not eat canned or raw food, only a few varieties of high-protein, low-fat, and low-carbohydrate dry cat food are available, but these foods should be selected for weight loss programs only when necessary.