Why do you need a Carb-Up day?

[JoNeS]

Ok two questions. Whats the point of carb-up day, wouldn't it be better to lose weight if you didn't carb up at all? Friend of my is currently on the less than 20g of carbs a day diet...every day. I told her do a carb up day (cuz thats what I read and hear everywhere) But she asks me why...and I don't know why. Also this girl, doesn't work out at all, she just does the less than 20g every day.

 

[OXANDRIN]

to up keep thyroid function
leptin production

you can go without it....but it is shown to provide better results

 

[chewyxrage]

if she doesn't work out then the carb up probably isnt needed.

the only reason i ever carbed up was so that i could continue to lift with intensity throughout the week.

 

[KWKSLVR]

Not to mention muscle preservation with the chance of an actual muscle gain.

 

[Stryc-9]

Yup, as others have said - the refeed is intended to stimulate an increase in blood plasma leptin (which drops dramatically when calories are reduced for extended periods - as in the case of someone on a diet!).

Low plasma leptin is one of the reason why low-caloric diets eventually lead to a stall in weight loss - it also leaves you feeling lethargic and ravenously hungry!! Leptin is tied to feelings of satiety and it essentially orchestrates the usage/storage of bodyfat.

As such, leptin levels are closely associated with one's body fat percentage. The higher the bodyfat - the higher the leptin levels (generally)....so people with higher percentages (say upwards of 18% or so) likely won't benefit from regular refeeds.

In contrast, people with lower levels of bodyfat will benefit from more frequent refeeds. e.g., once you drop into the single digits, you can refeed once every three or four days to keep on losing body fat.

People make the mistake of thinking that once they start losing weight - they can stick with the same diet until they reach their desired goal. But the body fights this weight loss every step of the way!! It senses the lowered calories and BOOM leptin drops and the metabolism slows down to a crawl (weight loss stops!!) and people become frustrated (and give up the diet!).

The refeed essentially jump starts the metabolic process and encourages continued lipogenesis (fatloss).

 

[JoNeS]

thx stryc karma

 

[juve]

To add to what has been already said. A significant drop in leptin levels has been shown to produce a response in which body starts to produce more of the neuropeptide Y - basically the thing that makes you feel the hunger/crave in times of fasting/semi-fasting.

A prolonged decrease in blood sugar and plasma insulin has also been shown to reduce serum testosterone and HGH levels over time - these are your anabolic hormones.

And then there's of course thyroid - the less you eat, the more your body 'wants' to hold on to its energy (nutrients -> adipocities)

 

[spiderwoman]

k- there was a really good article in muscle and fitness that made me rethink my weekly carb-loading day ... the Feb. 2003 issue, page 82 article states:
Women tend to have less muscle and more fat than men, and as a result they have less space in which to store muscle carbs [glycogen] and more space in which to store fat. Women also have 20% smaller livers than men; the liver is a key organ for glycogen storage.] Women protect their glycogen stores more than men. One spin-off is that women may benefit less from carb loading before a sports event than men.

 

[asiansINC1]

The girlfriend is currently on a low-calorie (not that high in carbs either, but not as low as 20g) diet. Would she benefit from a higher-calorie refeed-type day?

 

[swb1126]

You really don't need a carb up day. All you need to do is a high carb meal every 4th day in place of your last meal. This sends your body into panic mode and makes it work extra hard to burn all the carbs you just took in. By staying on a low carb diet all the time, your met. slows down.