Skin type changes

Ever since I started med school, changes have been the norm, and skin is no exception. During the progression of this school year (2012-2013) my skin type has gone from acne-prone, oily-combination to more of (less) acne-prone, dry-normal combination. 

Reasons for this?

1. I'm indoors a lot more. I have to be - I can't study outside in the Houston heat. It's crazy. Air conditioned rooms = dry rooms. The dichotomy between outside humid Houston weather and inside (relatively) dry weather really makes a difference.
2. My diet has changed. During college, the food I ate was often greasy and buffet-style. Now that I'm in med school, I cook for myself, and the way I naturally eat (basically when I'm hungry) has changed my life. I eat less greasy food, don't ever eat lard/butter, cook with canola and/or olive oil, don't eat bad stuff (usually), etc.
3. Weight changes. From high school to college, I lost about 10 pounds. The transition dramatically decreased my oil/sebum production (perhaps because I was becoming less sedentary, or eating less, or something?). Then, from college to med school, I lost another 5 pounds (net). This transition further decreased my oil/sebum production. Nevertheless, this has to do with diet and lifestyle changes.
4. My hair has changed. I know this may sound silly, but the hair's oils can cause a lot of acne as well, as hair in your face may help trap oil on your forehead and cause acne there. My hair is a lot less oily and (perhaps) weaker, due to changes in diet and not eating as rich stuff. Nevertheless, it has made a comeback with my use of hair serum and leave-in conditioner. Whenever I don't put it in now, it feels slightly straw-like, stiff, less rich or soft. During my younger, teenage years, it was just naturally soft and rich. Is it diet? Is it aging? Yes, I am past my early twenties now (sort-of? 23 y/o) and definitely my teenage years, but I am not that old.
5. All of the coffee I drink. Coffee is a diuretic - it causes you to, for lack of a better word, pee a lot more. Micturition happens a lot more frequently. Since water hydrates the skin and renews the body, one must replenish the body with lots of water to prevent dehydration. I must say that I am not very good at keeping up with this. I drink coffee almost like water (at least in the morning) to stay awake. Of course this is terrible - it's a terrible habit to have and maintain. I've never drunk this much coffee in my life.

Results of these changes?

• Whenever I look at sunscreens, I have to look for ones with many more emollient ingredients. This applies to facial moisturizers as well. The light, gel ones don't really hydrate my skin anymore - I just wake up with dry patches on my skin. Even the retinol I use has to be super moisturizing.
• Stuff doesn't break me out as much. Only about 1x/month I get a few acne spots. They are very light and then just go away.
• Less need for acne-driven products. I now use less products to "get rid of acne" and more products that are targeted toward hydrating the skin. Nevertheless acne still does pop up from time to time, so I have to look at that.

Bottom line, my shifts on views of products may change so people who have skin types similar to my old skin type may have different views of certain products I use/review/etc. On the other hand, people who have the skin type I currently have may find similar viewpoints. We'll see what happens!