Gaining weight in just seven days can be a challenging task, as it typically takes time to see significant changes in your body. However, here are some general tips that might help you gain weight in a healthy manner within a short timeframe:

Increase calorie intake: Consume more calories than your body burns in a day. Focus on nutrient-dense foods to ensure you're getting a balance of macronutrients and essential vitamins and minerals.

Eat frequently: Instead of having three large meals, try eating five to six smaller meals throughout the day. This helps increase your overall calorie intake without feeling overly full.