For decades you’ve been told to pile your carb consumption at the front end of the day. Eating a big, carb-laden breakfast, the so-called experts say, will kick-start your metabolism so you can more easily burn off everything else you eat for the rest of the day.
The latest scientific research tells a different story. Its main premise is to skip breakfast, avoid carbs for most of the day, then shovel them down your throat like crazy for dinner after training. The pay-off: an insulin spike that feeds your muscle cells and starves your fat ones.
The Cortisol Connection
To understand how this works, you need to know what’s happening in your body while you sleep. Your levels of the stress hormone cortisol elevate throughout the night, which isn’t as evil as you’ve been led to believe. Carbs are converted into glucose (sugar), which raises your insulin. When cortisol acts without elevated insulin (that is, before you eat carbohydrates), it triggers the breakdown of harmful triglycerides into free fatty acids for metabolisation. In other words, cortisol accelerates the fat-burning process in the morning – but only if you don’t extinguish it with carbs.
Burn fat, don’t store it
Your body also releases the “hunger hormone” ghrelin in the evening. As well as stimulating your appetite, ghrelin triggers the release of growth hormone. When this happens, your body releases more fat, which it can use for energy. This also decreases the destruction of protein for fuel so it can be used for muscle growth instead.
The problem? Insulin from carbs creates new fat cells and lowers your levels of ghrelin and, therefore, growth hormone, levels of which peak around two hours after you wake up. What that means: Eating carbs in the morning hampers fat-burning for the rest of the day.
The solution: Skip breakfast, consumer protein and fat for the majority of the day, train in the evening, then pound high-GI carbs at night. Low-GI carbs are shown to hinder the body’s night-time growth-hormone release. I call this system “carb back-loading”. It manipulates insulin sensitivity – which is high in the morning and low in the evening, especially after exercise – to control which cells grow and which don’t. Skip the carbohydrates during the day and you can reduce the insulin spikes that make fat cells grow. Load up at night after training and they’ll swell your muscles instead. It’s that simple.