A study published by Kaiser Permanente Care Management Institute’s Weight Management Initiative looked at the impact a food diary had on 1,700 men and women. The best predictor of weight loss wasn’t any particular element in anyone’s diet. Instead, it was how frequently the people in the study updated their food diaries. Those who wrote down their food daily lost twice as much weight as those who didn’t write down their food at all.
To create the most accurate food diary, write down the food choices and portion sizes of everything single thing you eat. Do it for a day, or even better, do it for a month—even if you don’t change a single thing you eat. Don’t forget to include the things you drink. A big mistake people make is writing down what they plan on eating. This can lead to inaccurate assumptions.