Port wine is a dark, sweet red wine typically enjoyed for dessert. True Port wine comes from the Douro Valley of Portugal and takes its name from the city of Oporto, according to the IntoWine website.
A 3.5-ounce serving of Port wine contains 154 calories, according to the Modern Wine Cellar website. By comparison, a 5-ounce glass of red table wine has 124 calories.
Your 3.5-ounce glass of Port contains 14 grams of carbohydrate and 14 grams of alcohol. Port is considered fortified wine, that is, it contains added alcohol, such as distilled Brandy, reports the Modern Wine Cellar site, upping its calorie content.
You may avoid alcohol to curb your calorie intake. A long-term study from Brigham and Women's Hospital in Boston showed that women who drank one or two glasses of wine daily gained less weight than women who abstained over a period of nearly 13 years, reports the New York Daily News. This finding did not hold true for men. While it's still unclear why the wine-drinkers gained fewer pounds, one theory is that people who drink wine may break down alcohol by turning extra energy into heat rather than fat.