I spend a disproportionate amount of my time telling women to eat carbohydrates (read: “safe starches”–see below). The thing is, a low carbohydrate diet (<50g/day) can do wonderful things for people. This we all know well. It’s a quick way to lose weight, to sharpen insulin sensitivity, and to reduce appetite in the short term, and it can be hugely therapeutic for people with cancer, migraines,and chronic infections or psychological disorders.
On the other hand, low carbohydrate diets can be a significant tax on people, women especially.
Because low carbohydrate diets are so popular for weight loss, it is common for women trying to lose weight and to “look good” to exercise often, eat very few carbohydrates, fast, and restrict food intake. The more of these restrictions a woman undertakes at once, the more and more her body reads this as living in a starved, stressed state. The results are significant. Her adrenals fire heavily, her liver gets tired from performing so much gluconeogenesis, her insulin sensitivity drops, her body fat levels fluctuate, her leptin signalling gets off, she stops sleeping soundly, and she stops menstruating regularly.
I cannot say that this applies to everyone. Many women undertake low-carb diets–Peggy the Primal Parent comes to mind as a fierce advocate (recently, however, she has, in her own words “scrutinized” and weighed evidence against the diet)–and feel great energy, life, and liberation from symptoms of their previous lifestyles. But women who are experiencing low-thyroid symptoms, menstrual dysregulation, sleep and or mood and mental health related issues may find significant relief from adding carbohydrates back into their diets.
-Glucose is necessary for the conversion of T4 to T3 in the liver. Certainly, the liver is capable of producing its own glucose with gluconeogenesis, but that process can become taxed over time, particularly if the woman’s liver is already taxed from poor eating habits in the past, mineral deficiencies, stress, or caloric restriction. Instead, when a woman ingests glucose, she assures that her liver does not have to work overtime. She provides the glucose that her brain needs, rather than forcing her body to make its on its own. This helps the body function more efficiently and with less stress in general, but it also specifically optimizes thyroid activity. Hypothyroidism is implicated in mood disorders, reproductive irregularities such as PCOS and amenorrhea, in skin conditions, and in weight gain, among other things. Many women, contrary to popular paleo belief, in fact lose weight once they add carbohydrates back into their diets.
This is true of clinical hypothyroidism, as well as sub-clinical hypothyroidism. Note that in many studies, women with cystic ovaries and sublicinical hypothyroidism see the resumption of regular ovulation when they correct their thyroid issues.
-Glucose elicits an insulin response, which in turn spikes leptin levels in the blood. This is a short-term spike, so eating carbohydrates should not be used as a replacement for body fat, which is the primary long-term secretor of leptin. However, moderate, regular consumption of carbohydrate spikes leptin frequently enough to help signal to the hypothalamus that the body is being fed. Recall that leptin is absolutely crucial for reproductive function. Without leptin, the hypothalamus does not tell the pituitary to produce sex hormones. At all.
-Moderate carbohydrate intake is associated with better mood, stress-reduction, and sleep, pretty well across the board. I see this in my work and in anecdotes, as well as in many controlled studies. The carbohydrate-well-being connection also plays out decently in biochemical theory. Carbohydrate intake (via insulin and albumin) boosts tryptophan levels in the brain, and tryptophan is the protein precursor to serotonin. Presumably, then, carbohydrate intake helps with the vast array of issues associated with serotonin deficiency which include moodiness, stress, and insomnia. For a look at the details and complexities of the issue, see Emily Deans here and here. The primary takeaway of this point being that while the exact mechanism of carbohydrates boosting mood and sleep quality is unknown, carbohydrates still appear to be a healthy, and in many cases necessary, macronutrient.
The whole point being that carbohydrates are not just okay but important. For women who have appetite control problems, sugar addictions, and a lot of weight to lose, absolutely I believe a low-carbohydrate diet can do them wonders. For women who struggle with menstruation, fertility, stress, exercise performance, or stress, along with any other hormonal oddities, carbohydrates help assure the woman’s body that she is healthy and fed. This is crucial for reproductive health.
In all cases, diet is a matter of personal physiology and experimentation. If a woman’s body works better on carbs, she should eat them, and delight in those joys rather than worry needlessly. At the very least, they are not harmful, and at their best, they are life saving.
Carbohydrates to eat:
I recommend glucose-containing carbohydrates rather than fructose for a wide variety of reasons, least of which are appetite control, liver function, and the prevention of metabolic syndrome. Many studies seem to be indicating that fructose is the real culprit in all of these problems. Glucose, on the other hand, when eaten absent of fructose has real satiating power.
I also recommend starchy glucose, since it is a “complex carbohydrate” and is broken down more slowly during digestion, which prevents blood sugar from rising or dropping too sharply.
Of course, grain-based carbohydrates are a no.
Finally, I recommend carbohydrates that contain nutrients over empty carbohydrates.
This means that I recommend eating:
Starchy tubers such as sweet potatoes, batata, jerusalem artichoke, cassava, tarot, and bamboo. Regular potatoes are fine, too, but they contain fewer vitamins than their sweet counterparts. Of the sweet potatoes, Japanese sweet potatoes are the most delicious, in my opinion, followed by white sweet potatoes and then yams and regular orange sweet potatoes.
For fruits, I recommend berries and cherries, which contain more glucose than fructose, and also bananas, which are pure 100 calorie glucose bombs.
Both white and brown rice are fine, but are fairly nutrient-poor. Brown rice contains anti-nutrients in it’s shell, so white rice is more innocuous in terms of nutrient absorption.
Vegetables of course are great, but they do not count for carbohydrate consumption. I know that much of carbohydrate content is indeed processed as glucose, but much of it is also tied up in fiber, which is broken down and turned into short-chain fatty acids by gut bacteria. For this reason, vegetables alone cannot make up a woman’s carbohydrate consumption. Instead, starchy tubers and low-fructose fruits work the best.
How much to eat:
For a woman recovering from stress, metabolic distress, and hypothalamic amenorrhea, I recommend eating between 100-200 g/day. That goes for athletes as well. And for pregnant women. At least 100 g/day.
Moreover, carbohydrates taken later in the day help with insulin sensitivity (since that gives the body the longest amount of time throughout a 24 hour period to operate at low insulin and leptin levels). They also, anecdotally, help put people to sleep.
Carbohydrates elsewhere in the paleo blogosphere:
Chris Kresser and Chris Masterjohn: Cholesterol, mostly, also: Telltale signs you need more carbs
Jimmy Moore: Is there any such thing as a safe starch?
Jamie Scott: A Week of It
Paul Jaminet: Higher Carb Dieting Pros and Cons (includes a discussion of the “longevity trade-off”)
Cheeseslave: Why I ditched low carb
Beth Mazur: Why I don’t eat low carb
Julianne Taylor: Okay, People, Carb’s Don’t Kill
Melissa McEwen (always a badass on women and fertility): What the bleep do we know about carbs
While you’re at it, go read Melissa’s post on Why Women Need Fat. Now.