Successful weight loss is all about oxidizing (or burning), more
calories than you eat. When they go on a diet, many people
choose low-calorie alcoholic drinks, mainly because they contain
fewer alcohol calories than their regular counterparts.
However, drinking too much has a far more damaging effect than
you can predict simply by looking at the number of alcohol
calories in a drink. Not only does it reduce the number of fat
calories you burn, alcohol can increase your appetite and lower
your testosterone levels for up to 24 hours after you finish
According to conventional wisdom, the infamous "beer belly" is
caused by excess alcohol calories being stored as fat. Yet, less
than five percent of the alcohol calories you drink are turned
into fat. Rather, the main effect of alcohol is to reduce the
amount of fat your body burns for energy.
Some evidence for this comes from research carried in the
American Journal of Clinical Nutrition. Eight men were given two
drinks of vodka and sugar-free lemonade separated by 30 minutes.
Each drink contained just under 90 calories. Fat metabolism was
measured before and after consumption of the drink. For several
hours after drinking the vodka, whole body lipid oxidation (a
measure of how much fat your body is burning) dropped by a
Rather than getting stored as fat, the main fate of alcohol is
conversion into a substance called acetate. In fact, blood
levels of acetate after drinking the vodka were 2.5 times higher
than normal. And it appears this sharp rise in acetate puts the
brakes on fat loss.
A car engine typically uses only one source of fuel. Your body,
on the other hand, draws from a number of different energy
sources, such as carbohydrate, fat, and protein. To a certain
extent, the source of fuel your body uses is dictated by its
In other words, your body tends to use whatever you feed it.
Consequently, when acetate levels rise, your body simply burns
more acetate, and less fat. In essence, acetate pushes fat to
the back of the queue.
So, to summarize and review, here's what happens to fat
metabolism after the odd drink or two.
• A small portion of the alcohol is converted into fat.
• Your liver then converts most of the alcohol into acetate.
• The acetate is then released into your bloodstream, and
replaces fat as a source of fuel.
The way your body responds to alcohol is very similar to the way
it deals with excess carbohydrate. Although carbohydrate can be
converted directly into fat, one of the main effects of
overfeeding with carbohydrate is that it simply replaces fat as
a source of energy. That's why any type of diet, whether it's
high-fat, high-protein, or high-carbohydrate, can lead to a gain
The combination of alcohol and a high-calorie meal is especially
fattening, mainly because alcohol acts as a potent appetizer. A
Canadian study shows that an aperitif (an alcoholic drink taken
before a meal to increase the appetite) increased calorie intake
to a greater extent than a carbohydrate-based drink.
Researchers from Denmark's Royal Veterinary and Agricultural
University report similar results. When a group of men was given
a meal and allowed to eat as much as they wanted, they ate more
when the meal was served with beer or wine rather than a soft
Not only does too much alcohol put the brakes on fat loss, it's
also one of the most effective ways to slash your testosterone
levels. Just a single bout of heavy drinking raises levels of
the muscle-wasting hormone cortisol and increases the breakdown
of testosterone for up to 24 hours. The damaging effects of
alcohol on testosterone are made even worse when you exercise
The effect of alcohol on testosterone could be one reason that
people who drink a lot carry less muscle. In fact, a 1993 study
shows that alcoholic men have bigger waists and smaller muscles
This doesn't mean you need to avoid alcohol completely.
A recent study, published in the November 2004 issue of the
International Journal of Obesity, compared the effect of two
different diets over a three-month period. Both diets contained
1500 calories daily, one with 150 calories from white wine and
one with 150 calories from grape juice.
Weight loss in the grape juice group and white wine group was
8.3 pounds and 10.4 pounds, respectively.
The bottom line
Although an alcohol-rich meal does increase your metabolic rate,
it also suppresses the number of fat calories your body burns
for energy — far more so than meals rich in protein,
carbohydrate, or fat.
While the odd drink now and again isn't going to hurt, the
bottom line is that alcohol and a leaner, stronger body just