The following are several methods that can be adopted to solve the problem of hamsters wasting food:

Have a transition period when changing food: When it is necessary to change the hamster food, don't replace all of it at once. You can mix the old and new hamster food in proportion and gradually increase the proportion of the new food, allowing the hamster to gradually get used to the new taste.
Moderate hunger therapy: If a hamster strongly resists a certain ingredient in the hamster food, you can try moderate hunger therapy. When ensuring that the hamster is in good physical health, let it go hungry for a few meals appropriately to see if it can correct its picky eating habit. But be careful not to make it sick due to hunger.
Diversified feeding: In order to maintain the hamster's interest in food, you can try mixing and feeding various types of hamster food, and occasionally give some snacks and nutritional supplements.
Reduce or suspend snacks: If a hamster is a picky eater because it has too many snacks, you can reduce or suspend the supply of snacks for a certain period of time to help the hamster readapt to the main food and reduce picky eating behavior.
Reasons for hamsters wasting food: Hamsters have the instinct to store food. They will stuff food into their cheek pouches and transport it to a place they consider safe for storage. In a caged environment, this behavior is easily mistaken for wasting food, but in fact, they are preparing for the future. In addition, hamsters have a relatively small appetite and can only eat a small amount of food at a time, which may make them seem more "picky".
Hamsters' dietary preferences and nutritional needs: Hamsters like to eat fresh vegetables and fruits, such as carrots, cucumbers, apples, pears, tomatoes, strawberries, etc. These foods should be washed and cut into small pieces to make it convenient for the hamsters to eat. Nuts and seeds are also good choices, such as almonds, sunflower seeds, pumpkin seeds, etc., but be careful to give them in small amounts to avoid health problems caused by high-fat foods. High-quality, sugar-free, and low-fat dog food or cat food can also be used as a temporary substitute, but it cannot be used as the staple food. Grains such as oatmeal and wheat germ are also nutritious choices.