According to a lecturer at Harvard T.H. Chan School of Public Health, watching TV for hours at a time can result in people becoming overweight and even obese as it encourages overeating. The lecturer explains that one of the issues associated with watching a lot of TV in a single session is that it can promote poor food choices due to the exposure of advertisements for food and beverages, which are often less than healthy.
The lecturer recommends that we avoid watching TV, refrain from gazing at our phones whilst we are eating, and purely focus on our food.
Read more (external link- Harvard School of Public Health)