I know I have a very poor diet. I have reached 21 years old and decided that if I don't change my habits now, I never will. Could someone please advise me on the good points (won't be many of them) and the bad points on my diet.

Average daily Diet:

Mon - Thur,

Pint of milk with vitamen tablet
Breakfast: Bran Flakes or 2 Pieces of Toast
Lunch: Lightly buttered bread and a packet of low fat crisps
Dinner: Half a plate of a potato product (chips, wedges, curly fries etc) with either red meat (burgers, steak pie, etc) or chicken

Fri,

Same as Mon- Thur apart from dinner. Dinner will normally be deep fat fried (tasty but unhealthy) curly fries with southern fried chicken strips and a peice of garlic bread.

Sat,

Normally forget to have milk and vitamen tablet
Normally not up till 11 so breakfast/lunch : Bacon Sandwiches
Dinner is same as Mon - Thur

Sunday,

No breakfast
Raw carrot before lunch
Lunch: Very Large Sunday roast consisting of...
Half a plate of boiled potatos
Quater a plate of roast potatos
Cooked Carrots
3 Yorkshires puddings
Large serving of meat (normall red meat like pork or beef etc)

If I am feeling brave:
Lunch may contain an apple, a banana and a organic yogot
I normally have some broccoli and cauliflower with my sunday roast.

If I am feeling peckish:
I will have a chocolate bar with lunch.
Will snack on chocolate, crisps, sauage rolls, or (rarely) biscuits
Very Large helpings for lunch or dinner

I am not over weight, but might get to that point if I keep going.
I try and have a 20 min light sprint (not jog) on tread mill each evening(average 5 times a week).
I might do 100 sit ups if its not too late at night (average 3 times a week I do sit ups).
To exercise my brain I am currently trying to learn web design in spare time.