Increasing Metabolic Rate
Contrary to modern media claims, eating breakfast as soon as you wake up is not the best or only way to 'kick-start' your metabolism for the day.
Metabolic Rate refers to both the amount of daily energy your body consumes and also the amount of nutrients it needs to maintain its current weight and/or body composition.
Eating food does of course have a metabolic effect on the body, involving the stimulation of various hormones as well as increasing thermogenesis via digestion.
However, if one wishes to increase metabolism - or at least improve the body's efficiency at burning its own stored energy (glucose and body fat), than it is far better to focus on exercise as the main component for increasing metabolism, rather than simply making sure you eat breakfast...
Yes, executing a meal plan is vital, but exercise is far more potent at increasing metabolic rate than food. What's more is that exercise can be timed in a way that makes your diet more effective.
Waiting a while before breakfast as well as performing some form of exercise before the consumption of food, will boost metabolism way more than just waking up and immediately eating something. It will also allow the body time to get into a digestive mode.
When you exercise on an empty stomach your body has no choice but to use stored energy (glucose + body fat) putting yourself into a fat burning mode at the start of the day. Plus, you are raising the metabolism while doing so.
It is not so much the 'fasted cardio' element at work but rather the fact you have raised your Metabolic Rate even before the consumption of food and now your body can properly absorb and utilise food you eat for breakfast. Exercise beats food!