| Study Associates Alcohol Use Patterns With Body Mass Index
The body mass index (BMI) of individuals who drink alcohol may be
related to how much, and how often, they drink, according to a new
study by researchers at the National Institutes of Health’s
National Institute on Alcohol Abuse and Alcoholism (NIAAA). In an
analysis of data collected from more than 37,000 people who had never
smoked, researchers found that BMI was associated with the number
of drinks individuals consumed on the days they drank. Calculated
as an individual’s weight in kilograms divided by height in
meters squared, BMI measures whether or not a person is at a healthy
weight low BMI values generally indicate leanness and higher
BMI values indicate being overweight.
“In our study, men and women who drank the smallest quantity of alcohol one
drink per drinking day with the greatest frequency three to seven
days per week had the lowest BMI’s,” said first author Rosalind
A. Breslow, Ph.D., “while those who infrequently consumed the greatest
quantity had the highest BMIs.” A report of the study by Dr. Breslow, an
epidemiologist in NIAAA’s Division of Epidemiology and Prevention Research
and colleague Barbara A. Smothers, Ph.D., appears in the February 15, 2005, issue
of the American Journal of Epidemiology.
“This is an important issue,” said NIAAA Director Ting-Kai Li, M.D. “Obesity
is prevalent in the United States and is a risk factor for numerous chronic illnesses
and early death. Since alcohol use also is prevalent in this country, it is important
to examine the relationship of quantity and frequency of consumption to body
The researchers examined data collected from 1997 through 2001 in the National
Health Interview Survey (NHIS), a nationally representative survey of the U.S.
population conducted each year by the National Center for Health Statistics.
Drs. Breslow and Smothers compared survey respondents’ alcohol drinking
patterns with their BMI scores. Since previous studies have shown that smoking
and drinking interact to influence body weight, the current study looked only
at current drinkers who had never smoked.
Results of previous examinations of the relationship between drinking alcohol
and body weight have been inconsistent. The authors noted that one possible reason
for this is that prior studies used a different way of assessing alcohol consumption
than did the current study.
“Alcohol consumption consists of two components,” explained Dr. Breslow, “the
amount consumed on drinking days (quantity), and how often drinking days occur
(frequency). Previous studies generally examined drinking based only on average
volume consumed over time. However, average volume provides a limited description
of alcohol consumption as it does not account for drinking patterns. For example,
an average volume of 7 drinks per week could be achieved by consuming 1 drink
each day or 7 drinks on a single day. Average volume may not fully explain important
relations between quantity and frequency of drinking and health outcomes such
The authors suggested several possible reasons for the observed associations
of both quantity and frequency of alcohol use with BMI.
“Alcohol is a significant source of calories, and drinking may stimulate
eating, particularly in social settings,” said Dr. Breslow. “However,
calories in liquids may fail to trigger the physiologic mechanism that produces
the feeling of fullness. It is possible that, in the long-term, frequent drinkers
may compensate for energy derived from alcohol by eating less, but even infrequent
alcohol-related overeating could lead to weight gain over time.”
Dr. Breslow cautioned against inferring cause-and-effect relationships regarding
drinking frequency, quantity and body weight from this study. The study points
to the need for prospectively designed studies to determine whether certain drinking
patterns constitute risk factors for overweight and obesity.
The National Institute on Alcohol Abuse and Alcoholism, a
component of the National Institutes of Health, U.S. Department
of Health and Human Services, conducts and supports approximately
90 percent of the U.S. research on the causes, consequences,
prevention, and treatment of alcohol abuse, alcoholism, and
alcohol problems and disseminates research findings to general,
professional, and academic audiences. Additional alcohol research
information and publications are available at www.niaaa.nih.gov.