Consuming carbs at night will get the best fat burning response. Simples.
I know this completely flies in the face of everything you’ve heard before about not eating carbs after 6pm (or whenever the magical witching hour is supposed to be). Claims such as “you should only eat carbs early in the day so you have time to burn them off” and “your metabolism slows down when you sleep so any carbs you consume in the evening will just be stored as fat” are frequently heard. On the face of it, I can understand why such statements are commonly accepted by the poor unsuspecting public, and why so many dieters cower in fear of carbs after dark.
In truth, the science points in the other direction: Eating the majority of your carbs in the evening will help keep you fuller and aid fat loss.
In order to explain this as simply as possible, we need to revisit our old friend cortisol. Poor old cortisol has been given a bad rep recently, and this is kind of justified. You might have heard me refer to cortisol as the “stress hormone” and, for those of you who have followed me for a while, you’ll know that chronic stress and chronically elevated cortisol can lead to weight gain. (Check out my article on stress HERE). When in balance, however, cortisol is our natural fat-burning hormone and is very beneficial to our health. Out of balance it causes havoc!
Cortisol is actually anti-inflammatory, and we all know that inflammation is bad news, so keeping cortisol levels in check is vital for health. To maintain optimal levels of cortisol we need to manage stressors, and managing food stress is crucial for a healthy gut. Any kind of food sensitivity or intolerance will increase inflammation and could manifest in any number of ways: Arthritis, muscle soreness, aching joints, headaches.
So how does all this point to evening carbs aiding fat burn? Well, here comes the science bit…
If cortisol is a natural fat-burning hormone, then it figures that we need to time our food intake with the natural highs and lows in cortisol production in order to capitalise on this. Cortisol starts increasing at about 2am and peaks just after we wake in the morning, then decreases naturally throughout the day. When cortisol is at a natural high (i.e. immediately post-waking) it triggers the breakdown of triglycerides into FFAs (free fatty acids), ready to be metabolised. It should be high in the morning to give us our “get up and go”, and low in evening to promote good quality sleep.
This is key: Cortisol and insulin have an inverse relationship. That means that when cortisol is high, insulin is low and vice versa. Consuming carbohydrates will spike insulin levels, thus suppressing cortisol. So wolfing down a piece of toast or bowl of cereal first thing will result in a drop in cortisol. Bye bye fat-burn!
With fat-burn naturally highest in the morning we want to make sure we don’t disrupt the hormone balance. Opting for high protein / high fat is your best bet as this keeps the insulin response low, and cortisol high (as it should be), essentially enabling cortisol to naturally decrease a few hours after waking. Consuming your carbs later in the day (try sweet potato, brown rice, quinoa, yams) will spike insulin, lower cortisol and allow your body’s hormones to follow their natural rhythm.
And if that’s not enough to convince you, think about it from an evolutionary perspective. Our ancestors wouldn’t have spent their mornings feasting on a large, starchy pile of food. (Ever noticed how you feel really sleepy after consuming a carbohydrate rich meal)? On the contrary, good old “hunter gatherer” would have been out doing just that: Hunting and gathering! He would have had a few berries or so for sustenance during the day, but then in the evening – after a hard day of work – he would return home to refuel with whatever he had gathered during the day, then settled down for a restorative sleep ready to face the next day of hunting.
Think about it. Work with your body’s natural rhythms and everything falls into place.
So to recap:
– Carbohydrates cause a spike in insulin, which leads to a rapid drop in cortisol (the natural fat burning hormone).
– Cortisol is naturally at its highest immediately after waking.
– Consuming starchy carbs in the morning will suppress cortisol.
– Opt for high protein, high fat in the morning. Save your carbs for your evening meal, or immediately after training.
Happy carb consuming 🙂