Keeping a food diary - a detailed account of what you eat and drink and the calories it packs - is a powerful tool in helping people lose weight, U.S. researchers said on Tuesday.
The study involving 1,685 middle-aged men and women over six months found those who kept such a diary just about every day lost about twice as much weight as those who did not.
The findings buttressed earlier research that endorsed the value of food diaries in helping people lose weight. Companies including Weight Watchers International Inc use food diaries in their weight-loss programs.
"For those who are working on weight loss, just writing down everything you eat is a pretty powerful technique," Victor Stevens of Kaiser Permanente's Center for Health Research in Portland said in a telephone interview.
"It helps the participants see where the extra calories are coming from, and then develop more specific plans to deal with those situations," said Stevens, who helped lead the study published in the American Journal of Preventive Medicine.
The technique also helps hold dieters accountable for what they are eating, Stevens said.
The study involved people from four U.S. cities: Portland, Oregon; Baltimore, Maryland; Durham, North Carolina; and Baton Rouge, Louisiana. Their average weight loss was about 13 pounds (6 kg). But those keeping food diaries six or seven days a week lost about 18 pounds (8 kg) compared to 9 pounds (4 kg) for those not regularly keeping a food diary.
The average age of people in the study was 55.
They were asked to eat less fat, more vegetables, fruit and whole grains, exercise 180 minutes a week mostly by walking, attend group meetings, and keep a detailed food diary.
Blacks made up 44 percent of the people in the study. The researchers noted that blacks Americans have a higher risk than whites for conditions linked to obesity including type 2 diabetes and heart disease.
"Keeping a food diary doesn't have to be a formal thing. Just the act of scribbling down what you eat on a Post-It note, sending yourself e-mails tallying each meal or sending yourself a text message will suffice," Dr. Keith Bachman, another Kaiser Permanente expert, said in a statement.
