A woman can gain weight quickly by consuming more calories than she burns each day. To gain weight in a healthy way, a woman should eat nutrient-rich, calorie-dense foods instead of empty calories. Strength training helps women gain weight in the form of muscles and also helps increase appetite, which makes increasing caloric intake easier.
Adding high-calorie, small foods to a dish or meal is a good way to increase calories without feeling too full. Olive oil, cheese, avocado and peanut butter are versatile options that increase the calorie content of a dish or snack with small portions. It's easier to include these in a diet by having more than three meals per day. An increased calorie amount spread over six meals is less likely to result in discomfort from overeating. Smoothies pack a lot of nutrients and calories from fruits, vegetables and other ingredients into a small snack, making them a good meal replacement.
Exercising builds muscle most efficiently when the diet includes large amounts of protein. A woman who increases protein intake and strength training can gain a lot of weight without adding fat or flab. Some light cardio before meal time, such as walking, can increase appetite.