The researchers note that the exact link between breakfast consumption and lower body weight is unclear, but there are several reasons. Children/adolescents who consumed breakfast tended to have a higher intake of total energy and total sugar, but breakfast skippers may tend to eat more foods with low nutrient or higher energy density - such as fast foods. Breakfast skippers may also eat increased numbers of discretionary calories (such as higher fat foods, candy bars, etc) later in the day. The researchers suggest that breakfast skipping may lead to excess hunger, rebound overeating, and consumption of larger portion sizes.
Breakfast consumption may be associated with an increased frequency of eating meals, which might provide a more steady flow of nutrients and prevent phases of hunger and overfullness, and may contribute to lower fat intake, higher overall nutrient-density, and may play a role in reducing body fat.