Your metabolism isn’t fast, you just don’t eat enough food. To gain weight you need to eat a calorie surplus. It’s simple math, if you input more calories than you spend, you will gain weight. To estimate on how much calories you need per day, also known as Total Daily Energy Expenditure (TDEE), check out the calculator on this site https://tdeecalculator.net/ It will give you a rough estimate of how much total energy you need to function daily. To gain weight eat 500 calories more than your TDEE. To achieve your weight goal, you need to eat foods with high calories aka calorie dense foods. Some examples include: - Peanut Butter - Avocado - Eggs - Milk - Yogurt - Olive Oil The above foods contain fatty acids which have more energy than carbohydrates (carbs) per gram. You can also eat foods with a lot of carbs like: - Spaghetti - Potatoes - Oats (አጃ) - Bananas - Bread To build muscle, your body needs proteins. Hence, you also need to include foods with high protein content in your diet . Examples include: - Chicken - Meat - Fish - Dairy products like Milk, Cheese and Yogurt Other main thing is you need to exercise to accelerate the process, be healthy and build muscles. If you work hard, you will reach your goals. Don’t try to take shortcuts as most of the time those advertised shortcuts don’t work Good luck! 💪🏽