Have you heard of the hormone called 'Leptin'? When you diet for a long period, your leptin levels drop very low, stalling your weighloss. ( I'm putting this in the most simple manner)
Leptin is actually made in fatty tissues, therefor, the lower your bodyfat, the less leptin you have. Can you see why lean people do need refeeds then? Leptin's main function in the body is to play a significant role in regulating both hunger, food intake and energy expenditure. As leptin levels fall, the greater your cravings become for all those wonderful foods that you used to eat when you weren't dieting.
Along with hunger pangs, low leptin also creates a slowing metabolism. Whenever you are on a low diet for an extended period of time, your body will begin to slow its metabolic functions in an effort to addapt to the amount of fuel that it is being given. Know what this means for you? Little or no fat loss. Not a good situation. aka starvation mode.
Now your goal is to raise your Leptin level again and speel up that slow metabolism. Leptin is highly responsive to glucose metabolism so when doing a refeed, you will benefit much more if the majority of your calories are coming from good sources of carbs that will turn into glucose. When done this way, leptin levels will show a significant rise over if you had eaten a surplus of calories coming from more protein, fat or fructose.
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REFEEDING
How much should you refeed yourself? This will depend on how long you have been dieting, how intense your diet is, and your current level of bodyfat. Those who are at a lower level of bodyfat will need to refeed more often than those who aren't. Similarly, the more extreme the diet being followed, the more intense the refeed.
Basically this has to do with how low leptin levels are. The lower the levels, the more calories above maintenance you will be needed to bring them back up.
Usually, a refeed should consist of 20-50% more calories than required for maintenance for 12 hours to two days. The higher you decide to bring your calories, the shorter period of time you will want to refeed for. If your leptin levels have almost dropped of the earth, you will want to refeed for a full week, but keep your calories slightly more moderate.
The downside to a refeed is that sometimes you will have to accept a small amount of fat gain. But, looking on the bright side, when you go back to your diet, your metabolism will be humming again and you should jump start the fat loss process. In a few individuals, they will actually become leaner during the process; however this is not the norm.
You can include some of your more desired foods in the refeed, after all, this is partly to relieve you psychologically from the restraints you feel during the dieting process, however make sure the rest is coming from good sources."