Jennifer Lopez eats four small meals a day to maintain her stunning figure.

The 'American Idol' judge is famed for her curvy-yet-toned body and insiders say she's careful with her diet as she wants to be in the best possible shape.

A source close to the mother-of-two said: ''Jen drinks ice-cold water to speed up her metabolism, bans carbs after 4pm and sticks to four small meals a day, which are packed with protein.''

As well as being sensible with her diet, Jennifer, 42, also works out regularly and trains with her 25-year-old dancer boyfriend Casper Smart.

The source added to Closer magazine: ''Jen is up at 6am every morning for an hour's exercise. She hates doing the same workout twice and likes to switch it up with core-strengthening routines, yoga or runs or the beach.

''She takes a skipping rope with her when she travels and, when she gets a spare moment, will drop to the floor to do around four minutes of sit-ups. Jen likes to work out with Casper as they really egg each other on.''