Here is why cyclical diets (or "cheat days") work.
 

When you fast, restrict, or otherwise deprive and stress your body with fat loss, your body begins to immediately adapt by triggering a cascade of hormonal adaptations. Among these adaptations are mild hypothyroidism. This is known as "starvation mode".

Once you initiate a refeed, your body immediately begins to replenish its thyroid hormone levels to normal. This increases metabolism again.

So you see, by taking yourself down to low levels of intake, but then "jump starting" the metabolism with high cal/carb days, you avoid the adaption to starvation (hypothyroidism).

Here are some studies which offer some evidence...

http://jap.physiology.org/cgi/content/full/88/5/1820

http://www.ncbi.nlm.nih.gov/entrez/...1&dopt=Abstract

There's, I'm sure, lots more studies out there showing how fat loss and energy restriction causes hypothyroidism and other endocrine abnormalities.

Bottom line. If you're stalled and expressing symptoms of conservation (no energy, dry skin, shedding hair, zero libido & other indicators of fertility abnormalities)... try eating more. Eat more carbs and eat until you are stuffed for 1 or 2 days. See if that works.
I personally noticed during my weight loss (which was achieved mainly by restriction), on days where I would binge on meats were often the days I lost more soon after. Many people have also noticed this correlation. At first I thought it was psychological or behavioral or some other simple explanation, but I've now come to totally support and rally behind the theory that staggering calories (and carbs) really works for physiological reasons.

But what if you have real hypothyroidism? Do you think this approach will work (considering that I'm medically 'corrected' for my metabolism)?

thanks!

Hmmm... I don't think it is that simple. I don't produce thyroid hormone at all so I have to take it in a daily dose. Therefore, all my thyroid comes in very steady doses every day. Yet I still seem to get a slowed metabolism when I diet and can, eventually, stall for awhile. I know it slows because I get cold all the time and its harder to lose weight.

Yet when my doctor looks at my thyroid levels, they look fine.

Why would eating a low carb diet with adequate calories, trigger a starvation response? I would think this is only true if the appetite suppression you experience, leads to a very low calorie intake to the point where you ARE in starvation mode.

I am more inclined to believe what that Ellis fellow said, that people given license to eat as much fatty food as they desire, overeat and take in more calories than they can burn. And that this results in a failure to lose at the point where their lower body mass burns the same as their intake. I know from personal experience, that I can still eat like a 215lb person. But I'm not that much of a man anymore, so I am training myself to eat portions commensurate with my current weight.

One thing that jumping back and forth between carbs and fats as primary energy source might do, is to keep you from metabolizing the fats efficiently. The long-term response of increased enzyme production might never kick in if you keep your body thinking it is going back to carbs as the energy source. This may keep the "metabolic advantage" at its maximum.

One thing the carb cycling may offer, is a way for people who are mentally unprepared or otherwise unable to stick to low carb for life, to be able to utilize lc as a weight loss tool. Knowing you can have your carby foods now and then, probably is a lot easier to live with for many folks.

I looked a the two studies you cited, and both of these were dealing with true semi-starvation diets right? So we are making a real jump, to assume that someone who is stalled is in starvation mode. Not saying it cannot happen, but I do think that the greater tendency, is to overeat the high calorie foods that are allowed in "unlimited amounts". At least that is my experience. Fortunately for me, I didn't hit a real plateau till I was nearly to where I wanted to be.

FOr a lot of us overweight folks, our eating habits include eating a large quantity of food. Now when we eat high-fat and low carb, we naturally get and stay full quicker. But I think some of the old habits can still bleed through this barrier to overconsumption. When you are used to eating a large volume, there is more to breaking that habit than just satisfying hunger. In fact, I don't think hunger was that much involved when I would scarf down 6 doughnuts at work.

Not saying the carb cycling isn't a tool to consider, just that the principles underlying its utility may or may not be explained through disruption of a semi-starvation state.

This is interesting... I've also noticed that I seem to have my best weightloss when I eat a lot of meat.

Nancy LC, can I get more information from you about your eating habits, g carbs/day, # calories, etc. Since we are both hypothyroid, I am encouraged by your success (Congratulations!) and would love to learn about how you accomplished it!

I've been very discouraged over the last 4 yrs, not being able to lose weight as a hypo, but you're proving it can be done. Any tips w/stalls, ideas for how much weight you typically lose/week or month, I'd really appreicate!

I agree with Wooo. Our bodies are amazing at adapting to all sorts of conditions. Although we may not understand all of the mechanisms, it is clear that we can adapt to certain diets with metabolic and enzymatic changes.

Carb cycling didn't work for me personally, because once I up my carbs it triggers cravings and I have a hard time getting back on plan. But if you can do it, I think it works.

Studies have shown that most people on low carb do eat less calories than they used to, even if they're not trying to. So an occasional cheat day should counteract the metabolic drop from eating less calories.

im gonna have to agree with that

For It's The Wooo--When you say "high carb/high cal days", do you still avoid sugar and refined flours on those days? Just trying to make sure that I understand the idea completely. For instance--on those days, do you just eat more of the whole foods such as veggies--even the starchy ones, and more of the normally allowed treats, etc.? I have to agree also, that the "meatier" days seem to leave me with a greater loss afterwards. :D

I completely agree with this. I've stayed very strict for a long time because it's done such wonders for my health, but I have noticed a few things:
-I have to watch calories now to lose weight, and keep them at a similar range that I used to aim for on low-fat,
-I have lost the "Atkin's breath", that ketone smell in general, I just don't seem to be excreting them all over the place like I did when I first started.

So I suspect that after 2 years my body has become extremely efficient at burning fats and that I have lost any "metabolic advantage" I used to have. I don't mind terribly, but if weightloss was my primary goal I would definitely feel a lot more frustrated. I'd like to lose faster but I haven't tried carb cycling because I'm worried about the effects of jerking my insulin levels up and down periodically.

Hmmm... I'm not sure you can say I'm hypothyroid really. My thyroid levels are normal because I take daily thyroid medication. But I do lose weight very slowly and I must cut calories to do so. Are you getting your condition treated? aka taking thyroid hormone?

Also, when I had Graves Disease, which is hyperthyroidism, I actually GAINED weight! Kind of paradoxical, but there you go. My doctors were surprised but said it wasn't unheard of just not usual. I don't think I ate an abnormally huge amount, but I was eating probably a pretty normal American diet, without sugary pop. You'd think someone with a resting pulse rate of 120 would be burning calories like mad.

For me, I have to keep my calories to around 1300-1400. I don't know that carb grams matter so much for weight loss, but I try to keep them 20 or fewer during the week. On the weekends I party with about 1600 calories and about 40g of carbs. I don't cheat, I don't have cravings or fall off the wagon. The lower carbs keep the appetite in check.

The only way I seem to lose weight is with calorie reduction. And my typical rate of loss is very, very slow. I've been on low carb for 1.5 years and have only lost around 35 pounds out of the 50-60 I need to lose. I find that I have to be very strict with calories otherwise I just maintain.

BTW: Part of the time after my thyroid was removed I was severely hypothyroid, they were waiting for my body to use up its stores so they could properly dose my thyroid hormone. And I was on Nutri/System at the time, exercising about 1 hour a day, eating 1200 calories a day and I totally stalled out for weeks until they got my thyroid dose right.

So my body has two rates of losing weight.... imperceptibly and extremely slowly. Make that three: Not at all. There's only one way to deal with that... time. Over time it does go. Patience is the key.

Nancy, thanks for your words of wisdom. Yes, I am on Levoxyl (137ug)..and have been at that level for almost 1 year. So, my hypothyroidism is in 'check', but I've been on the 1200-1300 cal diet w/exercise at 5-6x week (carbs probably around 150g) and either gained or maintained.

Starting Atkins now I am not really losing weight, I've lost a few inches here and there, but I managed to lose 10 on CAD just before switching to Atkins. I do feel better on LC WOE, but I still need to lose 15 lbs (am insulin resistant and don't want to tempt my body w/diabetes). After trying for 4 yrs to lose and not being successful, I DO want it to happen overnight (still would like atleast 1 WOOSH!)...but I agree w/your statement about patience.

I'm in a 4 week stall w/the scale, and it's getting harder to be patient when I feel like I'm just maintaining vs losing. Want to get the scale going again!

Just to throw my cents in, I tend to agree with its the Wooo based upon my experience. Please keep in mind I have had my thyroid checked and the values register normal, even though my body temp stays around 96.6 most days. I had been at 1200-1300 cal 20carbs exercising 45minutes daily and lost 3 lbs over 6 months. Those were lost when I actually increased my claories a bit sporadically to 1500-1600.

In addition, I was unable to exercise as I had been after a recent surgery and even keeping my calories at 1200 20 carbs with a daily 2 mile walk I gained 1.5lbs. that I am wokring on losing now that I can exercise fully again.

Finally, years ago when losing dieting strenuously, I lowered my daily intake to 500 calories an dmaintained my weight on that for several months (of course I was very unhealthy) but actually had to gain weight (10ish lbs) before I was able to improve my metabolism.

Th point, our bodies are very adaptable, some more than others. In times of famine this would be a great asset, but not so good when trying to lose weight and unfortunately your body does not recognize the difference.

Kristen

Kristen wrote: "In times of famine this would be a great asset, but not so good when trying to lose weight and unfortunately your body does not recognize the difference."

But we need not be in starvation mode when we lose fat off our bodies! In fact, this is detrimental to weight loss in the long run. We are simply eating the way we were meant to, and a normal apetite (and as a direct consequence, body fat level) is a natural result. When you eat low carb and take in a reasonable number of calories, your body doesn't think its being starved. It thinks what is supposed to be a realtively short "high carb season" is over, and its time to use fat for energy.