Indoor cats are particularly prone to becoming overweight due to their lack of exercise. When cats are kept indoors, they are not getting the same level of physical activity as an outdoor cat would. This means that they are not burning off the same amount of calories as an outdoor cat, leading to an increase in weight. Another factor that can contribute to an indoor cat becoming overweight is their diet. Many owners tend to overfeed their cats, giving them too much food or too many treats. This can lead to an increase in weight, as the cat is taking in more calories than it is burning off. Finally, some cats have a genetic predisposition to becoming overweight, meaning that even if they are given the correct amount of food and exercise, they may still gain weight. If your cat has a genetic predisposition to weight gain, it is important to try to control their diet and exercise as much as possible.