The technical term for it is called Specific Dynamic Action (SDA). Following consumption of a meal, your metabolic rate goes up by 10-17%. At first it was thought that this was related to stimulation of digestion activities. However, physiology based work confirmed that this is a by product of anabolic (protein synthesis activities) post feeding and nutrient assimilation. The experiment was very simple. They fed animals a meal of a set protein and energy content and in another set of animals they introduced the same quantity of amino acids, fatty acids and carbohydrates by i.v.. The introduction of assimilated materials into blood produced the SDA effect that was comparable to the meal given orally. Additional selective nutrient addition trials demonstrated that it was the introduction of amino acids, the building blocks of proteins, responsible for SDA.
So, yes, heat generation and metabolic rates increase after a meal and this effect can last up to a few hours post feeding. If you want to capitalize on the SDA mechanism specifically, then you want to consume protein. However, if you eat a pile of fats and sugars that will give your body lots of fuel to regulate regulate metabolic rate by the normal process.
