Here's how nutrition scientist Dr Hannah Theobald answered your questions about leading a healthy lifestyle.
Sparrow: My mum says you need five portions of fruit or veg everyday. Does a glass of pure orange juice count as a portion? My mum says it does
Hannah: Your mum would be right! We all should be aiming to eat at least five different portions of fruit and veg each day.
Make sure you don't eat the same ones each day as this way you will make sure you get a variety of vitamins and minerals that your body needs. Remember fresh, dried, canned and frozen fruit and veg all count.
Prettyandposh: I'm not a big fan of water and only drink about a glass a day, is that enough?
Hannah: It's really important to make sure you get enough fluid each day but it doesn't just have to be water. Fruit juice, milk, tea and coffee count as do fizzy drinks - but make sure you don't drink these too often.
Chickpea: How often can I eat McDonalds (or other fast food) without it damaging my lifestyle?
Hannah: Once or twice a month should be okay. A lot of fast food restaurants offer healthier choices. Try a fruit juice instead of a fizzy drink or a salad instead of a burger
xtina_4_eva: Is it bad to have starchy foods like bread and pasta for dinner because it's the time when I'm least active?
Hannah: It's a myth that eating starchy carbohydrates is bad for you. Pasta and bread for dinner is fine
Moonbeam: I can't have gluten or caisen (that's no wheat, barley, rye, oats or any animal milks). What healthy snacks can I have with these restrictions?
Hannah: Not being able to eat gluten or milk proteins does restrict your diet. Fruit and vegetables make an ideal snack. Popcorn may be OK as long as no wheat or milk products are used (check the ingredients list).
sarahlovesyou: Is there any way of testing whether you have an intolerance to certain foods? I mean are there tests to find out what personally makes you fat or ill?
Hannah: It is really important to see your GP if you think you have a food allergy or intolerance. They will be able to send you to the right specialists. If you cut out foods from you diet you may be missing out on important nutrients so you need to seek expert medical advice.
aka_fallen_angel: Is mineral water better for you than ordinary tap water? I think that mineral water tastes nicer but is there really any difference?
Hannah: You get some minerals from mineral water that you don't find in tap water but as long as you are drinking enough, that is more important.
Bubblelicious: are there any other foods other than milk, cheese and yoghurt that contain calcium?
Hannah: Dark green leafy veg contains calcium as do some calcium enhanced soya drinks and yoghurts and canned fish (not tuna). The calcium is in the bones. Bread also contains calcium in the flour.
Arcticgirl: I don't want to try it or anything, I wouldn't even dream of it, but I was wondering is the Atkins diet healthy, because some people think it's great and others have problems with it?
Hannah: The long term effects of not eating carbohydrates is not known. I wouldn't advise it to anyone especially not children. It restricts the range of food you eat and you could be missing out on vital nutrients.
Jamborene: Are McDonald's salads actually low fat?
Hannah: All salad leaves and vegetables themselves are low in fat but some salad dressings can be high in calories. Check the label.