This is another one of those myths that sounds logical when you think about it.  Eat your largest meal in the morning and all those calories will be “burned” off as you go about your daily business.  However, it is not true.  Our bodies’ burn calories breaking down and absorbing the food we eat.  This is called diet-induced energy expenditure and is responsible for about 10% of the calories we burn every day.  This idea of having breakfast be your largest meal has been around for sometime and is still popular today, you’ve likely heard the saying eat breakfast like a king, lunch like a prince, and dinner like a pauper.  Well, not everyone likes eating breakfast, especially a huge breakfast!  This eating pattern is sometimes referred to as the reverse diet because for most people, dinner is their largest meal of the day.  I could find no scientific evidence that showed the number of calories we use to digest and store food is any different for food eaten early in the morning, during the middle of the day, or late at night.  Actually, Taylor & Garrow (2001) reported that neither the number of meals we eat during the day, nor a morning fast had an impact on energy expenditure.  Research does show that skipping breakfast and consuming more calories later in the day is related to obesity.  However, there is not a cause and effect relationship between these two variables.  Skipping breakfast doesn’t “cause” you to become obese.  Maybe those who skip breakfast overeat at other meals, or aren’t as active as individuals who consistently have breakfast.  Keep in mind, weight loss or weight gain comes down to the simple equation of calories in vs. calories out.

Taylor M & Garrow J: Compared with nibbling, neither gorging nor a morning fast affect short-term energy balance in obese patients in a chamber calorimeter.  International Journal of Obesity (2001), Vol 25, pps. 519-528.