Yes, you can. But the weight you lose are mostly water weight and temporary, and you'll likely to gain back instantly once you have re-hydrated yourself.
The best advice for weight loss is to achieve effective calories deficit.
Weight loss is all about sustaining a calorie deficit, which can be simplified into a simple equation, as seen below:
Calories Deficit = Calories Expenditure - Calories Intake
To achieve calories deficit, calories expenditure will have to be higher than calories intake, and this can be achieved through diet and exercise.
Weight loss through Diet
To lose 1 pound, you would have to approximately burn 3,500 calories. Spread it out over a week would mean 500 calories per day. To lose 2 pounds, you will have to burn approximately 7,000 calories, and that would mean 1,000 calories per day. This calorie deficit can be achieved by controlling your food intake - a well-balanced diet filled with 45/30/25 carbs, protein and healthy fats respectively is recommended. (For more diet and weight loss tips.
A safe guideline to weight loss is 1-2 pounds per week. Definitely, to lose more weight quickly, you can increase your calories deficit of more than 500 per day. But this is generally not recommended as it may be harmful to your health. Thus, it is important to have a balance in your calories intake.
Fora step-by-step guide on how to count and calculate calories for weight loss, check out the following article.
Weight Loss through Exercise
To achieve calories deficit, there is a need to increase calories expenditure. And this can be achieved through exercise. There are a few types of exercise that can help you to increase calories expenditure.
A general guideline to weight loss would be at least 150 minutes of exercise per week. To increase calories expenditure, you can increase your exercise intensity as well as volume of training (Exercise Frequency). However, if you exercise too much, it can result in over-training and even lead to injuries. Thus, it is important to have sufficient exercise - not too little and not too much.