How fat is Tuesday?

I always thought Tuesday was the skinniest day of the week. After the excesses of the weekend that is always the day of full recovery. The New ‘merican Encyclopedia says the fat Tuesday is the fattest day of the year. How does the skinniest day of the week become the fattest day of the year?

Maybe in this bad economy Fat Tuesday should go on a diet. However given the unknown affects of economic stimulus, this may not be practicable.