You weigh yourself on different days each week
istock/Jacob Ammentorp Lund
In a Cornell University study published last year, researchers analyzed the food and weight diaries that 80 people kept for up to a year. They found that peoples’ weight fluctuated considerably throughout the week—many people were heaviest on Mondays (blame decadent weekend eating) and lightest on Fridays. Keep weigh-in days consistent for a more accurate assessment.
You miscalculate your clothing
File this one under “Yes, scientists have actually studied this.” When University of North Dakota researchers weighed people naked and clothed at various times of the year, they found that men can subtract 2.5 pounds for their clothing and women can shave off around two pounds, on average.