Although over 74% of individuals in the United States are either overweight or obese, there are also a large number of people who struggle with the opposite issue of being underweight. Some people may have a rapid metabolism or a hereditary predisposition to being underweight. A lack of weight may also be a sign of inadequate nutrition or underlying medical issues. In addition, many individuals who are not clinically underweight may nonetheless desire to put on weight and muscle for various reasons. The fundamentals are the same whether you’re trying to gain muscle weight or are clinically underweight. The most crucial thing you can do to gain weight is to consume more calories than your body requires, called a calorie surplus. Using this calorie calculator, you may estimate your daily caloric requirements. According to the calculator, you should aim to consume 300–500 calories more each day than you expend if you want to gain weight gradually and steadily. Aim for approximately 700–1,000 more calories per day above your maintenance range if you want to acquire weight quickly. Remember that calorie estimators are just that—estimates. Give or take a few hundred calories every day, depending on your needs. Although you don’t have to track calories forever, doing so for the first few days or weeks can help you get a sense of how many calories you’re consuming. There are many excellent tools available to assist you. For optimum growth, development, and human health, one must consume enough high-quality proteins from animal sources. A 2020 study including 23 people found that consuming more protein will result in more lean muscle mass. The Recommended Dietary Allowance of protein is between 1.0 to 1.6 grams of protein per kilogram of body weight per day for healthy people to enhance skeletal and muscular growth and physical strength with little to moderate physical exercise.