healthier
adj.adj. having better physical or mental fitness than before, or being better for your body. You use this to compare two things and say which one is better for your life.
adj. possessing or promoting improved physical or mental well-being relative to another state or entity. The comparative form of 'healthy'.
Eating more vegetables makes you feel much healthier.
Switching from soda to water is a healthier choice for your daily routine.
The latest public health report suggests that residents in walkable cities tend to be significantly healthier than those in car-dependent suburbs.
As a comparative adjective, it is frequently followed by 'than' when making a direct comparison.
more healthierhealthierHealthier is already a comparative form; adding 'more' creates a double comparative error.