Which of these is a sign of poor grooming habits as a result of substance abuse?

Neglecting personal hygiene is a clear sign of poor grooming habits that can be associated with substance abuse. Individuals who struggle with substance abuse may prioritize their substance use over self-care, which leads to a decline in personal hygiene practices. This might manifest in various ways, such as failing to bathe regularly, having unkempt hair, or wearing dirty clothes.

In contrast, the other options reflect behaviors that are generally not associated with poor grooming habits due to substance abuse. Frequent physical activity and maintaining a tidy appearance often indicate good health and personal care, while excessive dieting may suggest a focus on appearance or health, which also does not align with typical signs of neglect due to substance abuse.