Bulking is the process of gaining muscle mass by consuming a calorie surplus, which means consuming more calories than your body burns. It’s crucial to consume the right types of food for bulking to ensure that you gain muscle mass without gaining too much fat. Here are some foods that are ideal for a bulking diet.
It is essential to consume an adequate amount of protein to support muscle growth. Good sources of protein include lean meat such as chicken, turkey, beef, and fish, as well as eggs, dairy products, and plant-based protein sources such as beans, lentils, and tofu.
Carbohydrates are also important for providing energy and fueling workouts. Good sources of carbohydrates for bulking include whole grains such as brown rice, quinoa, whole wheat bread, and starchy vegetables such as potatoes, sweet potatoes, and corn.
Healthy fats are also important for supporting muscle growth, as they provide energy and help regulate hormones. Good sources of healthy fats include nuts and nut butter, avocado, olive oil, and fatty fish such as salmon. 
In addition to these macronutrients, it’s important to consume plenty of fruits and vegetables to provide the body with essential vitamins, minerals, and antioxidants. These nutrients help to support overall health and well-being and may also help to reduce inflammation and promote recovery from exercise.
When following a bulking diet, consuming a calorie surplus is essential, but this should be done in a controlled and gradual way to avoid gaining excessive amounts of fat. Aim for a moderate calorie surplus of around 250-500 calories per day, and monitor your progress to ensure that you’re gaining muscle mass without gaining too much fat. 
A bulking diet should focus on consuming plenty of protein, complex carbohydrates, healthy fats, fruits, and vegetables. By making smart food choices and consuming a controlled calorie surplus, one can support one’s goal of gaining muscle mass and achieving a more muscular physique.
Lunn NJ, Theis S, Leidy HJ, et al. Impact of Food Bulking on Gut Microbiota and Metabolic Health: A Systematic Review. Advances in Nutrition. 2020;11(5):1226-1239. Doi: 10.1093/advances/nmaa031
Slavin JL. Food Bulking: An Overview of Strategies for Increasing the Volume of Foods to Promote Satiety. Nutrition Reviews. 2017;75(9):727-737. Doi: 10.1093/nutrit/nux038