If you weigh 199 pounds can you lose 20 pounds in one month by eating once per day and doing sit ups?

The people who answered already obviously can't read! The question is not whether you can lost 20 pounds PER DAY, the question is can you lose 20 pounds in ONE MONTH by eating ONCE PER DAY!

It depends on how many calories you eat during that one meal and how many sit ups you do.

It would be pretty hard to do. I don't think you could do it unless you eat very little and do sit ups for hours every day.

I don't think it's healthy.