How quickly does a change in eating habits manifest?

Sure, along with stress. When we are stressed and busy our habits can suffer.
Are you getting enough rest, good sleep too?
When I am stressed and busy I need 9 hours a night, if not 10 sometimes to feel really rested.
Try improving your diet and making sure you are getting enough sleep. Everyone is different but the older I get I really need my rest too.

Yes, highly possible. At least drink a lot of water till you settle.

yes.

Absolutely. When I’m eating well, I can feel the effects of eating unhealthy junk food almost in real time. The strange thing is that when I have been eating unhealthy for a period of time, it takes some time (a week or two) of eating healthy again to feel better. But if I’ve been eating well and decide to eat a donut, I’ll completely useless for the rest of the day.

Thank you. I need to add: I meant to write “month” in the details, it’s only been about four weeks. I’m glad this might be the only issue – easily changed, and I’m more than ready to return to my normal diet anyway!

I can tell the difference in my energy levels when my diet flips between Wendy’s and anything that isn’t Wendy’s in about two days.

It could be a part of it (I would not rule out stress, which moving is). But consumption of sugar really affects my energy level, my joints and other things.

I tend to regularly eat a high quality diet, so when I shift to mostly junkie stuff, usually coupled with stress circumstances, I can feel the difference within a day or two. If the situation is really stressful, and the food is really junkie, after a week my gums bleed a bit and my gut is shot. I am a fragile flower, I guess. :-P

Good news is, my system gets back to normal in a couple of days if I go back to good food and alleviate the stress.

Three years ago, I would have answered this with some pious and arrogant statement about preservatives and processed empty-calories. However, life has a way of taming your certainties and, now that I’m in a constant high-stress position, I believe @ZEPHYRA has the best advice.

Healthy eating (hell, eating at ALL) is a luxury given to people with time. The insane pace of my job means I eat one meal a day and whether that meal is yogurt & celery or burrito and fries, the quality of food doesn’t seem to have anything close to the impact on my well-being as staying hydrated all day long.

Thanks, all. Stress is probably playing into it, too. Have been eating healthily yesterday, and noticed I’ve missed it more than I realized!