Many think that a big part of weight loss or maintenance of the fit body can be kept by tracking calories.

If we want to assess how much calories contains a food , and therefore tailor your daily menu, it would be better to accept a declaration on the product. Research conducted in America shows how our estimation of the caloric value of the food varies depending on the order in which we “scan” foods.

“Order, has the impact on our assessment of the food. Concentrating on the assessment in order is important because many of the meals ordered and eated at a fine foods, and not eated all at the same time, “said Alexander Chernev Northwestern University, who led the research.

His study found that people who first saw cheeseburger thought  it has 570 calories, while those who first saw a salad , and then a cheeseburger thought it has 787 calories, a difference of as much as 38 percent.

“If we just replace the order in which people evaluate two meals, we get a significant change in the perceived content of calories,” explains Chernev. Reordering is also changing the overall estimate of the total calories, with 757 calories in 1097 for the entire meal.

Next time you agree to your daily menu for a narrower waist, consider this hidden rule.