Question

For older adults, which of the following often goes up rather than down? Immune function fat mass bone density nutrient absorption.

Answer 1

I would have to say the best answer is fat mass

Answer 2

The answer is Fat mass.
As we got older, the efficiency of our metabolic process decreased, which make it harder for us to burn nutrient and transform it to energy.
Because of this, many of this nutrient ended up being stored away for future use in the form of fat, which eventually accumulated and creating a fat mass inside our body.