Our nation's greatest scientific minds have recently determined that going grocery shopping on an empty stomach is a bad idea if you are on a diet. The findings, by two researchers at Cornell University's Food and Brand Lab, have been published online in the Journal of the American Medical Assn. Internal Medicine.
Sixty-eight study subjects (19-62 years old, 71% female) fasted for five hours before doing their grocery shopping in a simulated online store. The e-market displayed everything from low-calorie items such as fruits, vegetables and chicken breasts to high-calorie products such as candy, salty snacks and red meat. Junk food items were displayed alongside better-for-you alternatives.
Half of the study subjects got to fill up on Wheat Thins (real ones, not e-crackers) before e-shopping. These subjects put eight low-calorie items into their shopping carts, on average: 2.44 snacks, 1.56 dairy items, 2.81 grocery items and 0.95 meats. They also added four high-calorie to their virtual carts, on average.
The other half of the study subjects did their grocery shopping on empty stomachs. They chose similar amounts of low-calorie items as the Wheat Thin-enriched subjects, on average: 2.84 snacks, 1.40 dairy items, 2.80 grocery items and 1.20 meats. But they chose six high-calorie foods instead of four.
Hungry people buy more yummy-looking food? You don't say!
To determine if such a difference occurs in real life, the researchers then examined the purchases of 82 shoppers in a real grocery store. People who bought groceries in the after-lunch time slot between 1 p.m. and 4 p.m., when an earlier study (really?!) had determined they were most likely to be full, bought an average of 11.2 low-calorie items and 2.69 high-calorie items, for a ratio of about 4 to 1. But those who went shopping in the pre-dinner time slot, between 4 p.m. and 7 p.m., when they were determined by previous research to most likely be famished, bought an average of 8.21 low-calorie and 3.81 high-calorie items, for a ratio of nearly 2.5-to-1.
The researchers, whose work is “independently funded by grants and consumer groups,” conclude that people should avoid making decisions about food choice when they're hungry.
Dr. Rita Redberg writes in an editor's note that “all diet guides include the advice to 'never go grocery shopping when you are hungry.'” The Cornell researchers “offer scientific support for this common sense advice.” Indeed. Thank God they cleared that up.
Next study: Will you buy more crap if you go grocery shopping with kids?
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