Guinness is a dark stout beer that is brewed with Irish barley, brewers yeast, hops and water. The water used to brew Guinness comes from Lady's well, a source of natural spring water in the Wicklow mountains. Guinness is often referred to as "liquid bread" or a "meal in a glass."
One pint is equivalent to 16 fl. oz. A pint of draught Guinness contains 168 calories, and has a 4 percent alcohol content. Guinness extra stout has a 6 percent alcohol content and provides 235 calories per glass.
One pint of regular Guinness contains 13.3 g of carbohydrates. Guinness has zero fat grams and is also fiber-free. Although Guinness has been promoted as a rich source of iron, one pint contains just 1.1 mg. The recommended daily allowance is 14 mg of iron for women and 8.7mg for men.
If you are on a weight loss diet, drinking alcohol will hinder your progress as the body will first burn the alcohol for energy instead of burning fat.