Some evidence shows breakfast can increase post-meal energy expenditure, but overall daily metabolism appears largely unchanged.
The evidence shows mixed results on breakfast's metabolic effects. Some studies demonstrate that breakfast consumption increases the thermic effect of food (post-meal energy burn), while meal timing studies found no significant differences in total daily energy expenditure or resting metabolic rate. The metabolic benefits appear modest and may be overshadowed by appetite control effects.
Caveats
Most studies focus on meal timing rather than breakfast specifically, and metabolic effects may be confounded by changes in appetite, food intake, and adherence to dietary interventions.