Abstinence/Sobriety (sometimes generally called Temperance) is the good habit of a man who has the self-restraint to moderate the amount and type of food/drink he consumes so as to maintain his health to have the longevity and vigor to serve God to the best of his ability. The man of Temperance eats to live, not live to eat. 

The opposing vices of Gluttony and Drunkenness are the bad habits of a man who lacks desire and self-control to moderate his consumption of food/drink (or drugs, tobacco, etc.) and habitually eats or consumes unhealthy things to excess, leading to the destruction of health due to obesity, disease and/or mental impairment. The Glutton is often finicky and pathetic in his unseemly desire for specific tastes and the attention, time and money he spends in pursuit of gourmet/exotic foods and drink to please his mouth.