Most light beers contain
about 100 calories, while regular only contains about 145
calories. Budweiser regular has 143 calories and Bud Light has
110, not much difference. According to Wikipedia,
Budweiser Light has 3.5% ABV per 12 US fl oz (355 mL) and
Budweiser regular is 5.0% ABV. It is made with up to 30% rice in
addition to hops and barley malt.
Light beer has been
brewed to be lower in alcohol, lower in calories, or lower in
both, depending on the brand. Low-carb beer has only been brewed
to remove carbohydrates, but can have the same alcohol content.
Most light beers are made from a process made possible in 1964
with the commercial introduction of amyloglucosidase. This
enzyme makes all the dextrins fermentable. Brewers generally add
water to adjust the alcohol content to slightly below that of a
regular beer.
Bottom line, with less alcohol, many tend to drink more light
beer, negating any calorie reduction benefits, and
costing more money in addition to consuming amyloglucosidase.