According to a survey of 1502 men by British menswear company Jacamo, twenty percent of men are anxious they'll feel fat in a bathing suit, and one fifth of men go on a diet before vacation. Men, they really are just like us! Unfortunately!
Naturally, the survey found that slightly older men were more comfortable with their bodies — those 55 and over were the most comfortable (forty-four percent vs. twenty-eight percent of 16- to 24-year-olds). If you have ever had a father who believes that a speedo is appropriate pool party wear, those numbers feel very possible.
Obviously, men feeling bad about exposing flesh is crap, because every body is a beach body, and it sucks for anyone to feel insecure about it. Wear whatever you want whenever you want and then shake nature's bounty all over this great planet of ours. Done and done.