WASHINGTON — Researchers at a New York City hospital several years ago conducted a test of the widely accepted notion that skipping breakfast can make you fat.
For some nutritionists, this idea is an article of faith. Indeed, it is enshrined in the U.S. Dietary Guidelines, the federal government’s advice book, which recommends having breakfast every day because “not eating breakfast has been associated with excess body weight.”
As with many nutrition tips, though, including some offered by the U.S. Dietary Guidelines, the tidbit about skipping breakfast is based on scientific speculation, not certainty, and indeed, it may be completely unfounded, as the experiment in New York indicated.
At 8:30 in the morning for four weeks, one group of subjects got oatmeal, another got frosted corn flakes and a third got nothing. And the only group to lose weight was … the group that skipped breakfast. Other trials, too, have similarly contradicted the federal advice, showing that skipping breakfast led to lower weight or no change at all.
“In overweight individuals, skipping breakfast daily for four weeks leads to a reduction in body weight,” the researchers from Columbia University concluded in a paper published last year.
A closer look at the way that government nutritionists adopted the breakfast warning for the Dietary Guidelines shows how loose scientific guesses — possibly right, possibly wrong — can be elevated into hard-and-fast federal nutrition rules that are broadcast throughout the United States.
This year, as the U.S. Dietary Guidelines are being updated, the credibility of its nutritional commandments has been called into question by a series of scientific disputes. Its advisory committee called for dropping the longstanding warning about dietary cholesterol, which had long plagued the egg industry; prominent studies contradicted the government warnings about the dangers of salt; and the government’s longstanding condemnation of foods rich in saturated fats seems simplistic, according to critics, given the ever more intricate understanding of the nutrition in fatty foods.
The Dietary Guidelines are important because they shape the contents of school lunches and other federally subsidized programs, and because amid widespread obesity, so many people look to them for sound eating advice.
The notion that skipping breakfast might cause weight gain entered the Dietary Guidelines in 2010. Much of the research was based on “observational studies,” in which subjects are merely observed, not assigned randomly to “treatment” and “control” groups as in traditional experiments. While cheaper and easier to conduct, such studies can lead scientists astray.
