Trekking in Nepal at Everest base camp trek is one of the most popular and visited adventure in the world and it is very essential to know about food, meals and drinking water available at trekking trails. Everest base camp trek is mostly tea house trekking where there are numerous teahouses and lodges all over the trekking routes that offers menu to visitors. In most of them you will find pasta, potato soup, eggs, chowmien, bread and pancakes along universal Nepali food dal bhat tarkari (rice, lentil and mixed vegetables).
While Trekking in Nepal at Everest region non veg items are rare after crossing Namche Bazar because of lack of refrigeration and added cost to bring it up and keep it fresh. However if you have high budget and staying at high end accommodations then veg, non-veg should not be an issue. You can get it. Carry some chocolate bars, yak cheese or canned tuna fish with you from Kathmandu for instant energy. Cost of these items can multiply several times if you buy them on the trail as all of these goods are eventually imported from Kathmandu with added cost. Mostly you will be served with boiled potato soup with mix of rice and noodles with fried egg on the top. It is the best sold food while trekking in Nepal and of course on Everest base camp trek.
Regarding the drinking water at Everest base camp trek, you can get bottled water all the way up to base camp but the price per liter goes higher and multiplies significantly. Per liter its 20rs at Kathmandu, 30 rs at Lukla and can go up to 200rs at base camp. Therefore, it is recommended to bring steripen (UV filtration) or iodine tabs for water purification with soft plastic bags so that you can purify the water from local source and make it safe for drinking purposes. At tea houses you will be served with boiled water. And please be noted that don’t drink water from local taps and resources as it would prone you to water borne illness and affects the whole trekking journey.
Alcohol is available while trekking in Nepal at Everest region. But another important thing to remember is to avoid alcohol and coffee as far as possible during the trek as it can cause dehydration and root cause of other illness including AMS. While returning from Everest base camp, however you can have a farewell party at Lukla and recall all those adventurous moments and accomplishments of being at base camp of top of the world.