Seeking advice to resolve the concern of milia in a growing child.

hello.

As a parent, it breaks my heart to see a growing child, at a time when they should be focusing on their studies and caring about their appearance, struggling with small, bumpy pimples on their face and around their nose.
However, surprisingly, the child's current appearance and worries are almost exactly the same as what I went through when I was a teenager about 20 years ago.
My heart feels even heavier because it seems my child has inherited the worries I had exactly the same way.

The child's situation is as follows.

The foods I like are the ones that particularly increase sebum production. I have an eating habit of enjoying pork belly, ramen, donuts, hamburgers, etc.
Furthermore, I have a constitution where I sweat profusely even with minimal movement, so I have a complex set of factors where sweat and waste products mix together, easily causing skin troubles and inflammation.

I am worried that my milia is becoming chronic due to these various reasons.
Neither the person involved nor I know what to do, so aside from applying a simple ointment, we have no choice but to just watch, and I feel frustrated wondering if I am making the situation worse.

I am looking for specific and practical ways to wisely overcome milia so that I can at least offer some advice.

1. Improving Eating Habits: How can you effectively reduce the intake of high-fat, high-sugar foods that a child likes and guide them toward an alternative diet?
2. Lifestyle Management: I sweat a lot. What are some daily skincare methods to minimize skin troubles and inflammation caused by sweat?
3. Professional Measures: If self-care alone is insufficient, what kind of professional treatment or topical medication (ointment) can be considered to remove milia cleanly without scarring?

I would appreciate some practical advice on this matter so that my child can overcome these milia concerns and regain confidence with clear skin.