> Metabolism is so complex There's really not much variation in metabolism. Most peoples' metabolisms are within ~10% of the average. [0] Of course, even a ve

> Metabolism is so complex There's really not much variation in metabolism. Most peoples' metabolisms are within ~10% of the average. [0] Of course, even a very small variation adds up when compounded over years. 100 extra calories a day is a 10 pound weight gain per year. But the variation itself is actually small. No one can "eat twice as much and not gain weight." [0] https://pubmed.ncbi.nlm.nih.gov/15534426 https://pubmed.ncbi.nlm.nih.gov/15534426