1. Undernutrition: Cats need to get enough nutrition to maintain their body functions. Hunger can lead to nutritional deficiency, which may affect the immune system and organ function.
2. Weight change: Hunger can lead to weight loss of cats, and long-term hunger may lead to muscle atrophy and physical weakness.
3. Digestion problem: If the cat doesn't eat for a day, the digestive system may be affected, such as increased gastric acid secretion, which may cause discomfort and vomiting.
4. Behavior change: Hunger may cause cats to become restless, excitable or abnormal.