An adult hamster will probably eat the equivalent of 10-15g of pelleted food in a day.
Your hamster will also appreciate some sort of gnawing food item. This can be in the form of dog biscuits or a small piece of deciduous wood. This is essential to prevent a hamster’s front teeth from becoming dangerously overgrown. Because hamsters love to gnaw, it is also essential that gnaw proof containers are used.
Of course, apart from hamster food, it is essential to have a constant supply of water available. This is best done by using a proprietary water bottle. An adult hamster can drink 15-20ml per day. The water bottle should be cleaned at least once a week, preferably with a bottle brush, and sterilised occasionally with a sterilising agent. You can use Milton or something similar. However, be sure to rinse the bottle out thoroughly afterwards to avoid any toxic buildup in the bottle. If water bottles are not washed weekly, algae growth will build up on the inside, giving a greeny colour to the bottle.