It depends, if you have attention span of a fruit fly, you will just join to a group of hundreds of thousands men who have ruined their penises. If not, then
You Might have some luck. Just take some Viagra and you will have answer: "Yes, penis can be bigger", but we are talking here about small increments at a time, and it also has to be so, because otherwise something breaks. You will get bigger penis just by dumping "fat ass food" and starting jogging. Sweat exercise promotes vein growth and health (your body releases some stuff during sweat exercise and it attaches inside veins and stimulates growth).
Your penis can also get smaller for the same reason as it can get bigger, usually from underuse or clogging your veins. Luckily we have night time erections to provide some regular use, if one lives like a monk otherwise.