If you want to lose a small amount of weight quickly, you should do so effectively and safely, no matter your reason for wanting to shed pounds. However, you can safely shed weight from retained water and waste, and lose 5 lbs. (2.3 kg) or more within one day. Be aware, though, that this process cannot be safely repeated for more than one day (i.e. you cannot safely lose 15 pounds in three days), and the weight that you lose in one day is likely to return quickly. It is smart to maintain a healthy body weight, and weight loss should be combined with long-term lifestyle changes, like eating healthy and exercising.
Based on my experience in nutrition counseling, most of us tend to snack on foods that aren’t nutrient-dense, but are high in calories. For example, skipping sugary beverages is often the easiest way to lose weight faster. You don’t feel full from drinks — even the ones that do contain calories — so swapping those out for sparkling water or unsweetened tea and coffee is the best place to start. Other major culprits often come in refined grains like cereals, chips, crackers, and cookies.