I have not had any caffeine since July 22, two days before the start of my locavore challenge. I've been drinking various herbal teas, and was happy to find that the rooibos and honeybush sold by my favorite vendor, Adagio, are organic. I've also enjoyed making tea from fresh lemongrass from the Free Farm Stand, and am looking forward to trying other fresh local herbs. As a result I'm sleeping better, and no longer have the stomach upset that sometimes accompanied the black tea I drank first thing in the morning. I realized that as much as I enjoyed that Irish Breakfast blend, it wasn't really doing my body any favors, and wasn't drinkable to me without soymilk and sugar.
To that end, I have also drastically reduced sugar. I haven't put any sweeteners - not only sugar but also maple syrup, agave nectar, etc. - into my own cooking since the start of the locavore challenge. I'm getting plenty of sweetness from fresh and dried fruit, tomatoes, yams, etc. I have eaten a few sugary things, such as a vegan donut offered at the farm stand (which I regretted), a few chocolate chips boyziggy put into a banana smoothie (without my knowledge until I started drinking it), and a group outing for vegan dim sum which included various dishes that probably contained sugar. But that's about it.
Same goes for salt. I am still eating salted peanut butter, but will replace it with unsalted when the current jar runs out, and other than that am not adding salt (or soy sauce) to any of my home-cooked meals. I have had a hard time finding good bread that contains no animal products, oil, salt, or sugar. Right now I'm trying Ezekiel which is made from sprouted grains and legumes. But ultimately I don't need bread either, it's just a habit.
This might sound like unnecessary deprivation, but I no longer see it that way. During my locavore challenge I re-read The Pleasure Trap, and got a new perspective on pleasure vs happiness. The very general idea is that eating things like sugar, salt, and oil, and using stimulants like caffeine, provide momentary spikes of pleasure, but not long-term happiness. The foods and drugs that are commonly and easily available in today's culture were once rare and precious. They were not meant to be parts of every meal, but special treats.
Unlike animal products (which I avoid for ethical, not dietary, reasons) and alcohol, I don't feel that I need to eliminate caffeine, sugar, salt, or oil from my diet completely or permanently. But I'm doing better without these substances, none of which have any nutritional value anyway. As long as I do my own cooking, I can avoid them, and enjoy the taste of foods closer to their natural state.