Before we discuss the specifics of gaining weight on a plant-based diet, it's essential to understand the basics of weight gain. Gaining weight requires consuming more calories than you burn. This can be achieved by increasing your overall calorie intake, increasing your intake of specific macronutrients (such as protein), or a combination of both.
Regarding macronutrients, protein is essential for weight gain, as it helps build and repair muscle tissue. Some healthy plant-based protein sources include legumes (such as lentils, chickpeas, and black beans), tofu, tempeh, seitan, nuts, and seeds.
Carbohydrates are also crucial for weight gain, providing energy for exercise and other physical activities. Some healthy sources of plant-based carbohydrates include whole grains (such as brown rice, quinoa, and oats), fruits, and starchy vegetables (such as sweet potatoes and squash).
Finally, healthy fats are an essential part of any balanced diet, as they help with nutrient absorption and provide energy. Some healthy sources of plant-based fats include avocados, nuts, seeds, and olive oil.