Time-restricted feeding is exactly what it sounds like, you restrict the amount of time in a day that you eat. So most people start eating around 7am and stop around 9pm, and that is being generous, many people start earlier and eat later than this. This is something you can calculate right now, but it basically means you are eating for 14 or more hours in a day, meaning you are not eating for less than 10 hours in a day. Time restricting feeding or eating is when you restrict that, perhaps to 10 hours, or some even to 4 hours. But obviously I am not recommending that and if you want to do it you should see your doctor first.
Studies in animals and very small studies in humans have shown potential here, with significant weight and fat loss and reduced hunger, even when people eat the same number of calories but in a smaller window. There are no big studies yet, but some are being down and due to be released soon. The good thing about this approach is you don’t necessarily have to focus and restrict your calories. It is time restricted feeding, not calorie restriction.
There are a few theories as to why this method may work. First is that you are eating more in line with your own natural internal clocks that are preset to process and digest food in a small window of the day, and certainly not at night. The second theory is around how our body uses the stored fuel we have. So we have essentially 3 sources of fuel in our body. The first is sugar, which is stored as glycogen in our liver and muscles. It is the first form of fuel we burn when we are exercising or we have not eaten. Then after between 12-24 hours, we start to run out of these, and much earlier if we are exercising. At this point our body scans itself for other fuel sources and comes across fat and sources of protein. Now protein is really important so it mostly spares that, but it happily uses fat as energy. Now if you watch the ketogenic diet video I did that will explain how our body turns fat into both sugar and ketones to use as energy.
So, basically if we restrict the time we eat to say 10 hours in a day between 8am and 6pm, that means we are fasting for 14 hours in a day. Then there is a good chance that in the last few hours of that fast we will be using fat as energy, and that is a very good thing.