Refeeding and Leptin>

Posted Sat 16th Mar 2013 12:38 AM by Dan Britchford in Fat-loss

Boring title, awesome idea. Breaking your diet every now and again and going a little bit crazy can actually benefit your weight-loss – it’s true. honest. And I’m not just talking about the occasional doughnut.. I’m talking about a day of whatever you want (kind of). Oh baby.

The reason behind this little gem of information, is leptin.


I’ve spoken a little bit about leptin before, and I don’t plan on going much deeper than I already have, but what you need to know is this:

Leptin is a hormone charged with regulating hunger and fat stores (and burning) within the body. In the short-term, the level of leptin in your body signals whether you’ve eaten enough, and in the long-term; whether you have adequate fat stores – meaning leptin has a role in telling your body when to burn body fat for energy. Good levels of leptin will reduce hunger, and keep your metabolism ticking over. Low levels of leptin, signify a slowing metabolism and increased appetite – not a good combination.

Simply put: if there was no leptin in your body, you would eat 24/7 and never feel satisfied.

And here’s the key point: leptin is secreted by fat cells!
So, generally speaking; the more body fat you have – the more leptin you have! People with more body fat secrete more leptin, which is their bodies way of telling itself ‘hey, we don’t need to eat as much’ and attempting to stall the growth of their (potential) beer belly*. BUT, it’s not just your weight; levels of leptin are also affected by short-term changes in your body’s energy balance, like a sudden switch to a caloric deficit or surplus. If you suddenly only eat half as much of what you were eating before (the deficit is severe), then your body reduces its secretion of leptin. It’s a mechanism to get you to take in some energy when it’s needed – your body doesn’t like when you lose weight too fast, especially when you’re already low body fat. It wants you to have some good stores ready for when a rainy day comes. Temporarily overfeeding (surplus) will have the opposite effect; raising leptin levels and reducing hunger.

*I’m not going in to why overweight people with more leptin (and therefore they should have less hunger) stay overweight, and don’t curb their eating. It’s a widely debated topic, and nothing is definite at the moment. However, the general idea seems to be that something inhibits the pathways of leptin, reducing its effects in overweight humans.

Refeeding and Leptin

So how can you use this knowledge to your advantage?

If you’ve been on a diet (in caloric deficit) for a while, three things will happen: your body will slow down its metabolic functions, you will lose body fat, and as a result: your leptin levels will fall. All three occur as your body tries to adjust itself to make do with this new, lower level of calories.

This is how we come to the idea of re-feeding; the process of strategically over eating for a short period of time while on a diet, to kick our leptin levels back up to reduce hunger and re-up our metabolism.

You may have heard this referred to as a ‘cheat day’ or ‘cheat meal’, but I’m postulating (take that dictionary) not many of you understood why it was a good idea (or even thought it was one) until now.

The general idea is that, with low leptin levels your results will suffer (slower metabolism means slower fat-loss on the same caloric deficit), and a sudden short period of overeating (caloric surplus) will kick-start both your leptin levels and metabolism back up again – leaving you less hungry and burning more calories.


  • Refeeding is best done by taking in around 20-50% more calories than maintenance, over either one or two days
  • The higher you go over on the calories, the less time the refeed should last for
  • The lower your body fat, the more often a refeed should be undertaken
  • Signs your body needs a refeed include: increased appetite, and decreased results (fat burning) when in a deficit

Leptin responds much better to your body burning glucose, than it does from using either fat or proteins as an energy source. So for maximal effect, go a bit carb crazy and get most of your calories from things carbohydrates, mostly low gi sources (rice, pasta, bread, etc) and then by all means go a bit wild with some foods you love.

If you want to have a crazy day of eating all your favourite foods, it may not be as beneficial as the above method, but it’s a viable (and attractive) option! and it counts!


this is the first place I’d go to get my extra calories!

blueberry muffins

I don’t have a reason for this image, I just like the food

food porn

Andouille Sliders

A final word and a warning

Not only do you get the leptin benefit from a re-feed, but doing so will also raise your testosterone levels (if you’re a male), which will have been dropping as you diet – and also reduce cortisol (the stress hormone). All this, and you get increased immune function! Which may also have taken a hit during your diet.

For the ladies among us

Leptin levels also play a part in the production of reproductive hormones. At very low levels, production of some hormones may be halted – and I don’t think I have to tell you that this isn’t good. Just as a precaution, if you’re dieting hard, make sure to re-feed every so often.

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About the author

Dan Britchford

Dan is the Editor/Designer/Developer, and Main Author of liftingthebar.com. His knowledge is gained through forum haunting and an active intrigue into all things fitness and nutrition based with a scientific grounding. When he isn't working on passion projects, or in the gym - he's selling himself trying to make it as a freelance web developer.

Dan has posted 30 times since 2013-01-31 15:06:30

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