Category Archives: Starvation

Very Low-Carb Dieting: Are the Hormonal Changes Risk-free?

I was in Chicago earlier this week to record a video discussion with Dr Ron Rosedale hosted by Dr Mercola. Ron and I have taken opposite sides in several “safe starch debates” (First installment here; reply to Ron here; Ancestral Health Symposium panel discussed here.) This new discussion was intended to be more cordial and uncover common ground as well as differences.

I was intrigued to see that Ron’s lunch consisted mostly of plant foods which he ate avidly; he said he believes that most people on his diet eat a significant amount of plant foods. I came away with the impression that the Rosedale Diet resembles the ketogenic version of PHD, only with less starch and MCT oil.

One of my objections to Ron’s recommendations has been that very low carb and protein consumption can be stressful to the body. Scarcity of carbs and protein invokes certain starvation-associated pathways – for instance, lower T3 thyroid hormone. We discussed this in “Carbohydrates and the Thyroid,” August 24, 2011.

Ron believes that low T3 on low-carb diets is healthy, and other low-carb advocates, such as Sam Knox, have made similar arguments.

I believe that intermittent fasting, which invokes starvation-associated pathways transiently, is usually health-improving – but that you can overdo it. What happens if you invoke these pathways chronically and continuously?

Prof Dr Andro on the “Athlete Triad”

Some light was shed on this question recently by Adel Moussa, aka Prof Dr Andro, who discussed the “athlete triad” in three posts (Part I, Part II, Part III) at his blog Suppversity.

The athlete triad appears most commonly in athletes who undereat and overtrain. Symptoms include low energy, amenorrhea in women and low testosterone in men, osteoporosis, reduced cognitive ability, and impaired immune function. The syndrome is surprisingly common, especially in female athletes:

Although the exact prevalence of the female athlete triad is unknown, studies have reported disordered eating behavior in 15 to 62 percent of female college athletes. Amenorrhea occurs in 3.4 to 66 percent of female athletes, compared with only 2 to 5 percent of women in the general population. [1]

As Adel discusses in Part II, the athlete triad is characterized by the following hormonal pattern:

  • low estrogen and testosterone levels
  • low T4 and low T3 thyroid hormone levels, often with low TSH and high reverse T3
  • a disturbed circadian cortisol rhythm lacking an appropriate cortisol spike in the morning and a normal decline in cortisol levels in the course of the day
  • low leptin, low insulin, and low IGF-1

Precisely the same hormonal patterns, including lower thyroid hormone levels, higher cortisol, and a suppressed circadian cortisol rhythm, are observed in total fasting and starvation. [2] [3]

These hormonal changes conserve glucose and protein, an appropriate step during starvation. The energy-intensive tasks of immune function and reproduction are temporarily suppressed until energy is more readily available.

Similar patterns of reduced T3 and elevated cortisol excretion were recently seen in a clinical trial of a 10% carb weight maintainance diet. [4] This trial shows that even in the absence of calorie restriction, carb restriction is sufficient to reproduce much of the “athlete triad”/starvation hormonal pattern.

This pattern reaches its most extreme form in anorexia:

[H]ypocaloric diets causes changes in thyroid function that resemble sick euthyroid syndrome. Changes consist of a decrease in total T4 and total and free T3 with a corresponding increase in rT3….

States of chronic starvation such as seen in anorexia nervosa are also associated with changes in thyroid hormone, GH, and cortisol secretion. There is a decrease in total and free T4 and T3, and an increase in rT3 similar to findings in sick euthyroid syndrome…. [T]here is an increase in GH secretion with a decrease in IGF-1 levels…. The changes in cortisol secretion in patients with anorexia nervosa resemble depression. They present with increased urinary free cortisol and serum cortisol levels. [5]

In chronic starvation, hunger is replaced by anxiety and a desire to move. In evolutionary context this urge to be active may have stimulated food-seeking, but in modern life it can exacerbate conditions like the athlete’s triad.

In Part II of his series, Adel made an interesting observation. Chris Kresser often mentions a patient who cured his health problems with pizza and beer. Here’s Chris recounting the story to Kurt Harris:

Chris Kresser: Back around 2000, I was interning for a holistic doctor down in San Diego, and this was before I got into Paleo or anything, and I was, I think, a vegan macrobiotic, for crying out loud, at that point!  So, we had a patient who was just really, really sick, and he was just getting sicker and sicker.  He weighed about 90 pounds.  I think he was about 6 feet tall.  And the doctor had him on a restricted diet, you know, one of those food allergy type of diets where all you’re eating is, like, broccoli, venison, and quinoa.

Kurt Harris:  The Specific Carbohydrate Diet?

Chris Kresser:  No, no, just like a really, you know, they do the IgG food testing, which is kinda bunk anyways.

Kurt Harris:  Yeah, that’s pretty bunk.

Chris Kresser:  And then they find out you can only eat strawberries, broccoli, quinoa, and ostrich!  You know?  And so, he was doing that, and he kept removing foods until he was literally down to, like, broccoli and steamed whitefish or something.  That was all he was eating.  And he just kept getting sicker and sicker.  So, he disappears for about six months, comes back a completely different person.  He’s back up to 160 or 170, which was his normal weight, you know, completely normal complexion.  Literally, we didn’t even recognize him, and the doctor was saying:  What happened?  Was it diet?  And the guy was like:  Yep, it was diet.  And he said:  Was it the candida diet?  Was it the Specific Carbohydrate?  What was it?  And he said:  It was the beer and pizza diet!  [laughter]  And this guy literally, I mean, the guy got to this point where he was like:  OK, if this is my life, I’m fine with just flaring out.  You know, this isn’t worth it.  And if I’m gonna go out, I’m gonna have fun.  And so, he started going out.  You know, he wasn’t ever hanging out with his friends anymore because he was on such a restricted diet, he had no social life, so he just said: Forget it.  I’m gonna drink beer and eat pizza at least three times a week, and then the other times I’m gonna do whatever I want.  And that completely restored his health.

Adel speculates (very plausibly in light of the man’s weight of 90 pounds!) that the patient was suffering from the starvation pattern which is replicated in very low-carb “euthyroid sick syndrome” and the athlete triad. What he needed was more calories, especially carb and protein calories. Pizza and beer are great sources!


It was a pleasure to chat with Ron and Dr Mercola in Chicago. We recorded a four hour discussion, which is going to be edited down to an hour or hour and a half.

We found plenty of common ground. We agreed that there are very real health benefits to low-carbohydrate diets. Low-carb diets are helpful against diabetes and metabolic syndrome, and quickly improve cardiovascular risk markers such as blood pressure, triglycerides, and HDL.

But in biology, good things can always be taken too far. One can restrict carbohydrates (and protein) too much. Extremism in carb restriction may, indeed, be a vice.


[1] Hobart J, Smucker D. The female athlete triad. Am Fam Physician. 2000 Jun 1;61(11):3357-64, 3367.

[2] Shimizu H et al. Altered hormonal status in a female deprived of food for 18 days. J Med. 1991;22(3):201-10.

[3] Palmblad J et al. Effects of total energy withdrawal (fasting) on the levels of growth hormone, thyrotropin, cortisol, adrenaline, noradrenaline, T4, T3, and rT3 in healthy males. Acta Med Scand. 1977 Jan;201(1-2):15-22.

[4] Ebbeling CB et al. Effects of dietary composition on energy expenditure during weight-loss maintenance. JAMA. 2012 Jun 27;307(24):2627-34.

[5] Douyon L, Schteingart DE. Effect of obesity and starvation on thyroid hormone, growth hormone, and cortisol secretion. Endocrinol Metab Clin North Am. 2002 Mar;31(1):173-89.