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Why your morning snack may be sabotaging your diet

Morning muffins — delicious snack or diet killer?
CC/Flickr/izik
Morning muffins — delicious snack or diet killer?

Snacking in the morning — as opposed to in the afternoon or evening — may make it more difficult to lose weight, according to a study published in the December issue of the Journal of the American Dietetic Association.

This finding — which surprised the study’s authors — may help, if only modestly, the 27 percent of Americans who are trying to lose weight on any given day. For surveys have revealed that 97 percent of Americans (including, presumably, those who are dieting) snack at least once a day. (And, yes, soft drinks count as snacks.)

Interestingly, however, much of the research thus far on the relationship of snacking with weight has been inconclusive.

Most in study snacked during the day
The study followed 123 postmenopausal women (average age: 58), who were either overweight or obese (mean BMI: 31.3). The women were part of a larger randomized trial that was investigating the association between body composition and breast cancer. Each was asked to keep a daily food journal for six months or until they met their weight loss goal (a 10 percent loss in body weight). No special instructions were given concerning snacking.

Some 97 percent of the women in the study reported snacking during the day. The most common snacking period was the afternoon (between 2 p.m. and 5:30 p.m.). The diaries revealed that 93 percent of the women snacked at that time of day, while only 19 percent snacked in the morning (between 10:30 and noon). About 30 percent grabbed an extra bite to eat in the evenings (after 9 p.m.)

Here’s what the researchers found after comparing the food diaries with the women’s weight at 12 months: Those women who didn’t snack in the morning had lost considerably more weight than those who did.

Specifically, the midmorning snackers had lost an average of 7.0 percent of their body weight, while those women who skipped a morning snack lost an average of 11.4 percent.

A surprising finding
“I was surprised that any particular snacking time was associated with less weight loss,” said Dr. Anne McTiernan, an author of the study and director of the Prevention Center at the Fred Hutchinson Cancer Research Center in Seattle, in an e-mail interview.

Dr. Anne McTiernan
fhcrc.org
Dr. Anne McTiernan

She and her colleagues believe their study’s finding may reflect the fact that there is usually a shorter time interval between breakfast and lunch. This means that individuals who snack during the late morning hours may be doing so mindlessly, rather than because they’re hungry.

But the study had another finding that may also explain the afternoon snackers’ greater weight loss.

“Afternoon snackers had a diet pattern higher in fiber, vegetables, and fruits — all foods that can increase your feelings of fullness, and therefore help to curtail intake of higher-calorie foods,” said McTiernan.

The take-home message
The study’s findings suggest several helpful tips for dieters.

“Our study showed that the most important keys to weight loss were writing down everything you eat every day, learning to count calories, and setting a calorie goal that will promote loss of about 1 to 2 pounds per week,” said McTiernan. She also advocates preparing your own foods as much as possible and exercising on most days of the week.

And what about snacking?

“We’d recommend that you use it as a way to avoid arriving at a meal very hungry, which can lead to overeating,” she said. “Snacking on a mixed meal, such as a protein and a piece of fruit or whole-grain carbohydrate, can help you feel full and reduce hunger.”

But be careful. “Snacking needs to fit within your calorie goal,” McTiernan stressed. 

“If you start snacking in the morning right after breakfast,” she said, “you may end up getting too many calories over the course of your day.”

Comments (2)

  1. Submitted by Ross Williams on 11/30/2011 - 12:18 pm.

    This is one of those studies where the only real response is “correlation<>causation”.

  2. Submitted by Rick Prescott on 11/30/2011 - 02:24 pm.

    Perhaps the actual study is more rigorous than portrayed in this write-up, but there are certainly red flags aplenty which might lead one to question the usefulness of the conclusion:

    “The study followed 123 postmenopausal women…19 percent snacked in the morning”

    That’s 23 participants, a very tiny sample size.

    “mean BMI: 31.3”

    Discredited measurement tool, potentially used inappropriately.

    “The women were part of a larger randomized trial…”

    Methodology (and sponsorship) of the larger study must be considered, along with data mining techniques used.

    “Each was asked to keep a daily food journal…”

    Unreliable self-reporting.

    “…for six months or until they met their weight loss goal”

    Not apples to apples.

    “Afternoon snackers had a diet pattern higher in…”

    Already, the lack of causation is apparent.

    Thanks for the report, but this is junk science and should be considered as such.

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