Is fat distributed proportionally around the body?
@fileunderwater's suggestion to use a scale is probably the best answer you could get, but looking at this broadly, the answer is no.  The oft-referenced apple and pear shapes are indeed very real and have medical consequences.  One of the issues is that there are sex differences in fat distribution.  There is no evidence I can find that finger fat is a good correlate of overall body fat, although admittedly yours could be.  It is also likely a function of how much overweight you were when you began the "experiment" i.e. the relationship probably isn't linear.

That being said, in men the ratio of the length of the second and fourth digits are otherwise meaningful.