Now here, they weren't estimating the calories they were just doing reports of how much physical activity they got and then the investigators calculated the calories and then the graph was created here.

说一下,实验对象没有实际估测卡路里,他们只是将运动量汇报给研究者,然后研究者进行计算,研究者绘制了这表格

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选