The sun is constantly consuming its own mass to generate the energy it radiates into space. Over its 4.6 billion year lifetime it has lost some 600 trillion trillion (6E26) kilograms of mass.
It still looks pretty big, you say to yourself, just a little worried.
You can relax ... this is only a few hundredths of one percent of the sun's total mass of 2E30 kilograms. The sun has barely noticed the weight loss.