First weigh the 3 slices of bread. If it is over 60g cut off some of the crust from 1 slice and weigh it again, until you get 60g.
Spray a frying pan with low calorie cooking spray and cook the bacon and eggs. You'll want the eggs quite hard so they don't make a mess when you eat the BLT.
If you want, you can toast the bread at this point.
Lay out the bread with the slice you cut the crust off in the middle.
Spread half of the ketchup onto one of the bigger slices of bread then place the eggs on top. Spread a little of the light mayo onto one side of the smaller slice of bread and stack on-top of the the ketchup and egg slice.
Spread the top piece of bread with a little more of the mayo, then add the bacon, sliced tomato and lettuce. Put the remaining mayo on the last piece of bread.
Place this slice on top of the lettuce and cut the sandwich in half diagonally. Enjoy!