Breastfed babies do not need to consume any other drinks (including water) other than breast milk. Even on hot days, breastmilk is the only fluid required until their diet starts to include the consumption of solids. On the contrary, bottle-fed babies instead may not receive the appropriate amount of fluids required and therefore thirst becomes more frequent. It is important to remember that if this is the case, other fluids can be consumed between feeding times.

The UK Food Standard Agency recommends the following list as a useful reference for fluids that can or can not be consumed during infancy:

Milks

• Breast milk is the best until one year of age. If breast milk is not an option, the only alternative is to feed the baby an infant formula.
  
  
• Ordinary cow's milk is not suitable for the infant. In particular:
  
  
  • Full-fat milk does not contain enough essential nutrients (too much salts and proteins) and therefore is not a suitable option until the baby reaches one year. Full-fat milk can be used in mixing foods when cooking from six months of age.
  • Semi-skimmed milk is not an option until the infant is two years old.
  • Skimmed milk is not suitable until the child reaches five years.
    
    
• Goats' and sheep's milk should not be feed until the baby reaches one year of age; these milk types do not contain the right balance of nutrients. If the milk has been sterilized with a particular process, such as pasteurization, which destroys harmful microorganisms without major changes in the chemistry of the food, then goats' and sheep's milk can be used starting from one year of age.

Other drinks should be considered once the baby is eating solids at least three times a day. At this age it is important to start introducing other fluids such as:

• Water - the best choice!
  For babies up until 6 months of age, tap water can be boiled (allowing it to cool) and feed. After six months, boiling is no longer necessary.
  Water from the bathroom tap is not appropriate for drinking because it may have been sitting in a storage tank. Bottled water is not a healthier option compared to boiled tap water. Some natural mineral waters are not suitable for babies as they contain too many minerals when compared to tap water.
  
  
• Fruit juices
  Some juices, in particular o range juice, are a good source of vitamin C but they also contain natural sugars and are acidic which means they can cause tooth decay.
  When feeding juices always dilute them being one part juice to ten parts water and offer this type of fluid only at mealtimes.  

Fluids which are not suitable for infants

The following drinks are not a suitable option for babies as these can cause bloating and can prevent the infant from eating more nutritious foods. Avoid the following fluids:

• juice drinks, fizzy drinks, sugary drinks and squashes
• diet drinks, ‘low-calorie' and ‘no added sugar' drinks
• flavoured milks and flavoured waters
• baby drinks and herbal drinks
• tea and coffee

Source: The UK Food Standard Agency