What items are you substituting??
If you are substituting "some items" in the recipe then your really no longer making bml, your making something else.
When you change some ingredients your likely changing the ratio for that staple. So you can't be sure what the ratio will be for what your making. For this reason it's not suggested to make substitutions in recognized diets, the ratios are already worked out in them and your changing it.
Now I'm not saying that about this cereal as Candy mentioned it's safe to use in BML. But other ingredient changes can effect the staple considerably. If for some reason your gliders don't eat BML very well, and many don't, then it's time to find a different staple altogether, not change the recipe.
I tried and tried to get mine to eat bml and for a while there they did. Then all the sudden I was scrapping it all off the plate in the morning. So, a change had to be made.
Many folks find they are in the same boat with it. Now it is a widely used diet and a good one. But it's not doing your gliders any good if you have to change it to get them to eat it. If that's the case Find a different one that they will eat with out making substitutions so they are getting the right amount of vitamins and minerals out of it and are able to make the most out of the calcium they get.