While Invisalign doesn’t directly cause weight loss, the process of having to take them out for every meal and then brushing your teeth afterward can encourage some patients to plan what they eat for the day. Since your aligners are meant to stay in your mouth for at least 20 to 22 hours a day, it’s important to consider what your snacking habits are. Most patients who have undergone Invisalign treatment reported to have lost a certain amount of weight.