Question: Is this describing a (1) directly correlative relationship, (2) conditionally causative relationship, (3) causative relationship, or (0) no relationship.

Interventions aimed at modifiable correlates may include maintaining a normal body weight and regular physical exercise for maintaining a  normal waist circumference, and decreasing caffeine consumption, implementing feasible modifications in sleeping environments and maintaining sleep hygiene to  improve sleep quality.
user
This is a directly correlative relationship
assistant