Fiber doesn’t contribute to weight gain as it isn’t digested or absorbed by the body. However, foods that contain fiber have calories, and overeating these foods can contribute to weight gain. For example, eating large quantities of high-fiber foods such as nuts and seeds can take your daily calorie intake over your energy needs, which leads to weight gain.
The good news is that most high-fiber foods are also filling and can contribute to satiety, which makes it less likely that you will overeat (7). You’re unlikely to overeat fruits, vegetables, and whole grains as they’re high in both fiber and water, which can help you feel full before you consume too many calories.