Sorry, but it&#x27;s pretty unlikely this is true.  The biggest TDEE difference seen in studies is about a 300 calorie difference for people of the same weight (so not enough to have 150lbs people recklessly eating thousands of calories and not gaining weight).    It&#x27;s very likely you have members of your family who don&#x27;t eat a lot day to day and eat a ton at family gatherings etc.<p>If I&#x27;m wrong here I have a lot of scientists who would like to examine your family.