Study Shows Between-Meal Snacking Doesn't Reduce Eating at Mealtime
Nov. 15, 1999 (Atlanta) -- Before you reach for that between-meal snack,
consider this: a new study suggests that snacking will not only do nothing to
curb the amount of food you'll eventually eat at the next meal, it could even
contain the most fattening calories of the day.
French researchers came to this conclusion after studying the body's
response to additional food intake in the interval between a decent-sized lunch
and a buffet dinner. Eleven lean, young men participated in the study, which
took place in four sessions over two weeks' time.
The first session was devoted to finding out how much the men ate of a given
lunch, as well as how soon afterwards -- unprompted by a clock -- they were
hungry enough to ask for dinner. During this interval, the researchers took
frequent measurements of blood glucose and insulin concentrations to get a
biological picture of how the men's bodies usually reacted to food intake and
During the next three sessions, the men ate identical lunches. The
difference was, the researchers introduced a snack between lunch and dinner and
the men had to eat it, regardless whether they were hungry.
To test for hunger during the lunch-to-dinner interval, the men were asked
to report frequently whether they felt satisfied. And to make sure it was
actually hunger and not habit, the men were kept in isolation during the
sessions -- so that they had no idea how much time had elapsed since lunch nor
whether it was 'time' for dinner. The subjects asked for dinner at about the
same time regardless of whether or not they had a snack.
The study results raise questions about snacking's impact on weight gain.
But dieticians contacted by WebMD had some problems with the study's methods.
Jackie Berning, PhD, RD, an associate professor of nutrition at the University
of Colorado in Colorado Springs, zeroed in on the study's finding of no big
change in blood glucose levels in the men, despite their having consumed a
snack. "Storage, to me, is the big question. ... The assumption I got [from
the study] is that [snacking] tends to favor storage, which would tend to favor
fat. But they don't know that. Maybe [the extra glucose] is going to the brain.
Maybe [the subjects] were reading a hard book. Maybe it's going to the liver or
muscles. If they're twitching their foot maybe it's going there."
A recent poster presented at the American Dietetic Association's annual
meeting by researchers from the University of Memphis concluded that timing of
food intake is unimportant when it comes to putting on weight. "Some say
timing has an effect on fat storage and body weight. We found it does not,"
says Linda Clemens, EdD, RD, a professor at the school. Clemens questioned the
"artificial environment" in which the study was conducted, as well as
its small size, but calls the results interesting.