Rudyard Kipling wrote:
I keep six honest serving-men
(They taught me all I knew);
Their names are What and Why and When
And How and Where and Who.
So first up: What is fasting in Islam? Basically it's going without food or drink from dawn to dusk. It also involves staying away from all vices (sex, smoking, etc) during those hours, as well as working harder to please God through every act of worship from kindness to prayer.
Next: Why do Muslims fast? For much the same reason that Jews fast Yom Kippur and some of the reasons that Christians fast - to attain piety through humility, and develop a closer relationship with God. You can't show off when you're fasting, because only God knows if you're not cheating.
Thirdly: When do Muslims fast? It's just Ramadan, right? Wrong! Although Ramadan is the one time when Muslims HAVE to fast, it's not the only time that we are encouraged to do so. The other important religious fasts include six days in the month following Ramadan, the first 10 days of the last month in the Islamic calendar (which is the month in which the Hajj pilgrimage takes place) especially the 9th Day (the Day of Arafat) and other days, too.
Also, there are times when fasting is forbidden in Islam, most notably the two Eid celebrations.
Then there's How Muslims fast. Other than the fact that everyone doesn't eat, drink or have sex between sun-up and sun-down, there are no specific rituals involved. This has led to great cultural diversity across Muslim lands, which sparks a lot of curiousity and comparing of notes. All good fun. A lot of people get up early before dawn to have a breakfast, that can consist of anything from cereal to a full, several course dinner. (I’m not kidding, I’ve personally witnessed people eat 3+ courses for breakfast in Ramadan).
And then there is breaking the fast. The Prophet Muhammed (peace and blessings be upon him) said that God says that the two happiest times in a Muslim's life are when they break their fast and when they meet their Lord. This is so true. The pure bliss when breaking your fast is unparalleled. But what to break the fast with? Traditionally, it's dates, but it can be anything, from water, milk, soup, dinner, an entree, anything at all. This is then followed by a dinner, called Iftar.
Next up: Where do Muslims fast? Everywhere ... unless they are travelling. If you're on a journey or are away from home for a few days you don't have to fast, as the toll of travel can make you weaker.
Last, but not least: Who has to fast? Everybody at, or over, the age of puberty, male and female, who will not harm their health by doing so. So kids and anyone with a medical reason not to fast, as well as pregnant/breastfeeding women who fear for their and/or their child's wellbeing are exempt. Also, women on their period don't fast.
Now that I’m done with that, I’ll address one of the biggest misconceptions regarding Ramadan: that fasting for a whole month will make you lose weight. It doesn’t. Trust me on this. My mum once fasted Ramadan before she became a Muslim with the hope of losing weight and she lost nothing. Why? Well, because you can still eating anything you like in the evening. And worse yet, a lot of people put on weight in Ramadan because they think that having eaten nothing all day they can eat whatever they want, and however much of it, they like. Sadly, that’s not true.
And it’s quite common for non-Muslims to try it out, for various reasons. I know one person who did it just to see if they could, and another who lived in an area with a large Muslim community and wanted to join in. Also, there are lots of opportunities for people to meet up for an evening meal.
A member of a fire department participates in an Iftar.source
For some truly amazing photos of Muslims during Ramadan/Eid from around the world, check out the Boston Globe's Ramadan 2010 photo gallery.