The MetFix mission is one focused on improving the health and fitness of its members (regardless of where they begin their journey) through regular performance of constantly varied functional exercise and the consumption of a nutrient-dense diet of real foods that provide plenty of quality complete protein and good fats, absent much starch or sugar. Particularly in people who start out distinctly unfit metabolically, who have been sedentary and eating a typical diet of processed foods, high in starch, sugar, and industrial seed oils for some time, the changes brought about by adopting the MetFix methodology can be stunningly rapid, especially improvements in metabolic measures, such as triglycerides, blood sugar, blood pressure. Early on people will typically notice improvements in energy, sleep quality, and mood (exercise is a great antidepressant). Weight loss, fat loss, and muscle gains take a bit more time, but will follow suit with perseverance and consistency.

And, unfortunately, for some people, so will hair loss.

Shedding pounds of fat is a welcome benefit of making a positive lifestyle change; shedding hair not so much. But over years of caring for people following a well-formulated low-carb diet, I’ve seen it happen to men and women alike.

Why, they ask, when they’re eating better, living cleaner, and working harder are they now a few months into their new program suddenly losing hair? And I can assure you that seeing a shower drain full of hair is cause for considerable consternation. The natural human tendency is to link such a phenomenon to some deficiency in the newly adopted nutritional program – “I started this new keto thing and now my hair is falling out!” Quite often they’ll blame and even abandon their new diet. So, this is something coaches should be aware of, and if it happens, be prepared to reassure a client who experiences it that it’s nothing to worry about.

The likeliest explanation is telogen effluvium—the medical moniker for it.

(One word of caution: the likeliest cause of hair loss doesn’t mean only cause, so persistent cases merit a visit to the dermatologist to search for other causes.)

What is Telogen Effluvium?

Sudden loss of hair can accompany a wide range of systemic conditions. Illness and high fever can cause it. Anesthesia, radiation, some medications, and surgery can as well. Pregnancy, too. And so can marked weight loss, from dieting, GLP-1RA use, obesity surgery, or whatever cause. Paradoxically, changing your lifestyle positively by exercising properly and eating right can even cause it.

The explanation lies in the physiology of hair growth.

Humans are born with about 5 million hair follicles on their bodies, with between 100,000 and 150,000 of them residing on the scalp. The number is fixed before birth and doesn’t change, at least it doesn’t increase (though in the case of genetic baldness, the number can decrease when some of them simply quit functioning). Each hair shaft grows out of a single follicle that throughout the course of its life will cycle repeatedly through various growth stages. These are:

• Anagen: the active growing stage (usually lasting years) in which the stem cells and matrix in the follicle base are actively dividing and producing keratin, elongating and thickening the hair shaft. Normally about 85 to 90% of the 100,000 or so hairs on the average human head are in this growth phase at any one time.
• Catagen: a brief transition phase (lasting a few days to weeks) when a small percentage of the active hair follicles begin to slow down the cell division and keratin production that elongates and maintains a hair shaft in preparation to rest a while.
• Telogen: a phase following catagen, lasting 2 to 4 months, when the follicle is completely at rest. The hair shaft it’s built remains anchored to it, but the hair is no longer growing. Normally only about 10 to 15% of the follicles on a human scalp are in this dormant state at any one time, a feature designed to prevent synchronous shedding and over-thinning of the hair.
• Exogen: the shedding of dormant hair shafts.

Major metabolic stressors, such as those listed above, or sudden metabolic changes—even positive ones like making a major beneficial dietary shift—can throw a much larger percentage of active follicles suddenly into telogen, the dormant state.

After making the big switch, for example, from the Standard American Diet to a low-carb/ketogenic structure, at first there’s nothing much to see, because the ‘old hair’ is still anchored in place, even though the hair follicles have been put into telogen. Everything seems to be going well for a few months, but that resting stage will pass in two, three, four months, and when it does, the dormant follicles will re-activate. The old hair shafts of those re-activating follicles are finis, caput; the follicles can’t add onto them any longer. They can, however, build brand new healthy hair shafts from the ground up. And that’s what they do.

As the tiny new hair begins to form in the base of the follicle it ultimately pushes out the old, dormant hair shaft, and the scalp loses that hair. When 25% or 30% or 50% or more of the active follicles have been thrown into telogen by the sudden systemic stress or metabolic change, they will start to be pushed out in rapid succession, causing telogen effluvium—the flood of shedding hair caused by a large number of follicles coming out of their resting phase at once.

If inspired by the metabolic changes wrought by switching to a nutrient-dense diet, be assured, everything is in place to ensure new shafts are growing. They’ll ultimately be visible as fine new hairs around the edges of the hairline if you look with care. Certainly it will take many months of active shaft growth for a tiny new hair to replace a longer one that’s been shed, but the person will in time recover their normal head of hair. Or maybe even a shinier, more vibrant one.

The main takeaway is to recognize telogen effluvium is not an uncommon event. It may occur in anyone 2 to 4 months out from surgery, major illness, pregnancy, and sometimes just from making the transition from a lousy diet and sedentary lifestyle to the MetFix methodology. It doesn’t happen to everyone, but occurs often enough that a coach will want to be aware and step in with reassurance that this, too, shall pass. The explanation of what’s going on is usually enough to keep that person traveling their road to metabolic rehabilitation.