To lose weight effectively with the help of water intake, the amount you should drink varies based on your weight, sex, activity level, and individual needs. Here are key guidelines:

• General recommendations: Women typically need about 9 cups (about 72 ounces or 2.1 liters) of water daily, and men about 13 cups (about 104 ounces or 3 liters) to stay hydrated

. Many health authorities also suggest the "8×8 rule"-eight 8-ounce glasses (about 2 liters) per day-as a simple baseline

• Weight-based calculation: A practical formula is to drink half your body weight in ounces. For example, if you weigh 150 pounds, aim for about 75 ounces (2.2 liters) daily

. Overweight individuals may require more; a 200-pound person might need around 100 ounces (3 liters) daily

• Before meals: Drinking about 16 ounces (500 mL) of water before each meal can reduce appetite and calorie intake, potentially leading to about 5 pounds of weight loss over 12 weeks when combined with a reduced-calorie diet

• During exercise: If you work out regularly, you should increase your water intake beyond the baseline. For example, add about 12 ounces for every 30 minutes of exercise, and hydrate before, during, and after workouts as follows: 17–20 ounces 2–3 hours before, 8 ounces 20–30 minutes before, 7–10 ounces every 10–20 minutes during, and 8 ounces within 30 minutes after exercise

• Benefits for weight loss: Drinking enough water can boost metabolism temporarily, increase fat burning, reduce hunger (sometimes thirst is mistaken for hunger), and help control calorie intake since water has zero calories

• Cautions: Drinking excessive water beyond your body's needs can be harmful. Let thirst guide you after meeting these targets, and avoid overhydration

In summary, aim to drink at least half your body weight in ounces of water daily, increase intake if active, and drink water before meals to support weight loss. This hydration strategy complements diet and exercise but is not a standalone solution