StopJetLag uses the naturally occurring fluctuations in your body's energy reserves to help switch your sense of time to a new pattern. In your pre-flight days, the Large Meal/Light Meal pattern alternately builds up and depletes your glycogen (blood sugar) reserves, which prepares your body's clocks for adjustment. Light Meal Days are days in which your meals should be small and low in both calories (40-60% below normal) and carbohydrates. Be sure to consume enough food on 'Light Meal' days to avoid any feeling of weakness. On Large Meal days, you should consume significantly more calories than usual; your breakfasts and lunches should be high in protein (eggs, meat, fish, dairy products, legumes, etc.), but your suppers should be high in carbohydrates (rice, pasta, potatoes, cereals, etc.). Try to consume 2/3 of your daily protein foods at breakfast and lunch. You can refer to the Plan's Sample Meals page for additional information.
The type of food you eat is important because of the chemical cues specific food types give your body. High-protein meals stimulate your 'catecholamine' pathway which is normally activated early in the morning; it's what wakes you before your alarm clock rings and it serves to stimulate the body's active phase. High-carbohydrate meals stimulate your 'indoleamine' pathway, which normally occurs in the evening of your circadian cycle when you are winding down to a night of sleep.
Meals don't have to 'look' like your typical fare for a particular time of day, as long as the content and size of the servings is what's recommended in your Plan pages. For instance, if the airline is serving a breakfast of either French toast or a cheese omelet, and you are supposed to be having a high-carbohydrate supper, you should choose the French toast because of its high carbohydrate content.
Following the StopJetLag plan for the final Light Meal day before you change to a new time zone is most critical. In the natural glycogen cycle, breakfast acts as a signal of phase change to your body - it tells you to start the glycogen storage phase - and a hearty breakfast when you have eaten lightly serves as an even stronger signal of phase change. Thus, the Large Meal breakfast on destination time firmly cues your body to the new time pattern.