A water fast is when a person does not eat or drink anything but water for a set period of time. This obviously results in rapid weight loss because your body is not taking in any calories through food. However, the weight you lose through fasting will come back when you start eating again. In fact, because your metabolism slows down to deal with the lack of energy coming in through food, you may gain back more weight than you lost in the first place when you start eating again.  If you’re trying to lose permanent weight, you should drink plenty of water in concert with balanced meals and regular exercise. However, if you need to drop a few pounds for an event, a water fast might be a quick solution for you. The human body is incredibly resilient, and can last a long time without food — so long as it’s not dehydrated. Fasting for a few days is not harmful to most people as long as they drink plenty of water — which you’ll want to do anyway to trick your stomach into thinking you’ve eaten something.  However, people with some medical conditions should not fast under any circumstances. Diabetics, for example, need to regulate their blood sugar with food throughout the day. Consult your doctor before beginning a fast. Children, the elderly, pregnant or breastfeeding women, and people with chronic illness should not fast. Even otherwise healthy people will feel negative side effects while fasting. When you stop eating, your body doesn’t have an energy source; as a result, you will feel fatigue and dizziness. You may also feel nausea or suffer from constipation, and, obviously, you will feel very hungry. You may want to consider a clean eating cleanse instead. Focus on eating lean proteins, vegetables, fruit, nuts (i.e. almonds and cashews), and complex carbohydrates like sweet potatoes, brown rice, and quinoa, for at least 48 hours. You may see recommendations for 21 or 30-day fasts online, but these are extremely dangerous if not under direct medical supervision. If you choose to fast, do so only for the three...

How would you rephrase that briefly using Indonesian?
Anda harus memahami bahwa berpuasa dengan hanya meminum air tidak akan memberikan hasil yang permanen. Pertimbangkan faktor-faktor kesehatan yang membatasi sebelum Anda mencoba berpuasa hanya dengan meminum air. Berpuasalah hanya selama beberapa hari. Berpuasalah dalam kurun waktu yang tidak membuat Anda merasa stres. Bukalah puasa sebelum menghadiri acara yang ingin Anda kunjungi.