So what you're saying is that I should put her on a forced diet.
If you have to force her to please her husband-to-be, you should consider whether she's worth it. Would you have to discipline her all the time?
What would you say was the most Christian way of going about it, atkins perhaps?
Some sort of a modified stomach pump? Or should I simply keep her chained to the basement
but cut out six of her seven daily servings of lard and hummus?
Definitely not Atkin's diet nor any of those other unnatural choices. The Bible tells us what to eat! And if we follow the Bible, we have a healthy diet - those who are obese will lose weight, and those who are too thin will gain some flesh around their bones.
Tell her to start with Genesis 1:29-30. And God said, Behold, I have given you every herb bearing seed, which is upon the face of all the earth, and every tree, in the which is the fruit of a tree yielding seed; to you it shall be for meat. And to every beast of the earth, and to every fowl of the air, and to every thing that creepeth upon the earth, wherein there is life, I have given every green herb for meat: and it was so.
Every plant yielding seed includes barley, wheat and other grains; seeds includes sesame and sunflower seeds (both have lots of fibers); legumes - soybeans, lentils, peas, peanuts, other peas etc. (all very healthy); green herbs include eggplant, okra, bell peppers, green beans, cucumbers, etc.; fruits include citrus fruits, swee fruits, palm fruits; nuts - almonds, pecans, cashews, walnuts, etc. All meat - which is not unclean (see Lev. 11) - is also allowed.
Note how healthy this diet is! No potatoes (not mentioned in the Bible!) nor sugar. (Honey is allowed, of course).
I start to wonder - have you even read the Bible? These are very important verses.