[amenghra]

Data point = 1 but my kids eat/drink 2-3x less than I do. They weigh 5-7x less.

[gruez]

That's because they're growing, not because they weigh less.

[jakeinspace]

In general, smaller organisms tend to consume more calories or resources per mass of body weight than larger ones. One reason, for mammals especially, is that maintaining homeostasis means scaling energy input with surface area, since that’s what radiates away heat. Surface area roughly scales with square of height, while mass scales with volume (cube of height).