Jennifer Aniston allows herself a cheat day once a week.

The 46-year-old actress tries to watch what she eats by sticking to a strict low-carb, gluten-free diet filled with lots of fruit and vegetables but she allows herself to fall off the wagon at least once every seven days because she believes it's important to indulge every so often.

She explained: ''On Sundays I eat whatever I want. Otherwise, I stick to a low-carb, gluten-free diet with lots of protein and vegetables. I love brown-rice bread - it's really good for you. Just put a little coconut oil and sea salt on top. Delicious.''

The 'Cake' star - who is engaged to Hollywood hunk Justin Theroux - also combines her diet with a gruelling workout routine in order to stay in shape and keep her fitness levels up.

She said: ''My workouts are usually an hour to an hour and a half, four to five times a week. But if I don't have much time I can cram a lot into a half hour. I'll do 10 minutes of cardio then circuits. [Three sets of three exercises]: lunges, squats and push-ups. I just go hard for 30 minutes without stopping.''