Brown RE, Canning KL, Fung M, Jiandani D, Riddell MC, Macpherson AK, Kuk JL. Calorie Estimation in Adults Differing in Body Weight Class and Weight Loss Status. Med Sci Sports Exerc. 2016 Mar;48(3):521-6.
A new study published in the March 2016 issue of Medicine & Science in Sports & Exercise, we examined how well lean and overweight adults who were or were not attempting weight loss can estimate the number of calories they expended during exercise, and the number of calories in a meal. Fifty-eight adults exercised on a treadmill at a moderate and vigorous intensity for 25 minutes each and then estimated the number of calories they expended. Following they created a meal that they believed to be equal to the calories they burned during the exercise session. On average, most groups were able to accurately estimate the number of calories burned during moderate and vigorous exercise and create a meal of equivalent calories. However, there was a considerable range of each individual’s ability to estimate calories in both exercise (279 kcal underestimation to 754 kcal overestimation) and food (760 kcal underestimation to 468 kcal overestimation). In particular, the individuals who were overweight and not trying to lose weight were the worst at estimating calories as they believed they expended 72% more calories than they actually did during vigorous exercise by 72%, but also overestimated the calories in food by 37%.
Given that understanding calories if critical in long term weight management, the poor ability to estimate calories in food and exercise, particularly for adults who are overweight and not trying to lose weight may be why it is so difficult for individuals to lose weight through diet and exercise.