What percentage of carbs, fat and protein you should eat is one of those areas of nutrition in where there is a lot of opinion and not a lot of scientific fact. And probably for good reason: much of it depends on your genetic makeup, your ancestral heritage and your current state of health.
Yet many of us still want a reasonable guideline, and would probably rule out the Standard American Diet (as reflected in the USDA’s dietary guidelines) as the best starting point for these macronutrient ratios.
Some would argue that there is no point in looking at ratios at all, since Paleolithic man did not care about how much of which macronutrient he was consuming (much less what a macronutrient was). If he came across something edible, he would eat it! No doubt, this is probably true, however, he wasn’t faced with an overabundance of food at his reach, as we are today.
Paleolithic man did not have the modern concerns of being much too overweight, nor did he need to worry about the tolls of chronic stress that our modern society imposes on the body.
I personally wanted to know how much fat I was eating, because, almost 2 years ago, I went on a ketogenic (Very Low Carb/VLC) diet. I was prescribed this diet by a chiropractic doctor who prescribed it to everyone. It was his answer to everyone’s ills, despite what they might be.
Even though he did not know the source of my chronic digestive trouble, he nonetheless, thought the ketogenic diet was the answer for me. I was hesitant at first. Not because I didn’t believe that the diet didn’t have its benefits. But because I didn’t know if it was right for me.
I only committed to the idea when I received a test result (from a different doctor) showing that I had fructose malabsorption, and so needed to avoid a long grocery-list of foods that contained fructose (we’ll save that discussion for another day). Going ketogenic made it a lot easier to get the calories I needed while avoiding those that were causing me digestive distress.
So I needed to determine what was a good ratio of fats to carbs in order to achieve nutritional ketosis. It didn’t take me long to get there. I was already eating fairly low-carb as it was. I could now simply add extra delicious fats to my diet, without feeling guilty. My digestive issues became much better, my headspace cleared up (ok – I can still be a little spacey, sometimes. But I prefer to call it daydreaming. No brain fogs here). I had a nice, slim figure, and I could eat all the bacon I wanted. What’s not to like?
Until I started Crossfit this fall. Now, I have never been a stranger to exercise. Before I had kids, I worked at a botanical garden 5 days a week, digging holes, planting trees, pushing wheelbarrows full of soil and mulch, clipping branches, and walking. A lot. After work, I would go to the gym several days a week to lift some weights, and swim in the pool.
After the kids were born, I signed up at the closest gym that had a daycare accepting babies as young as 6 weeks of age. I enjoyed all kinds of aerobics classes, as well as HIIT (High Intensity Interval Training), and, as a new mom, was not very sedentary at home.
But there was something about Crossfit that hit me differently. I can’t really blame it all on Crossfit. There is a nexus of different factors coming together here (another discussion for another day). But Crossfit was the straw. You know, that (almost literally) broke my back.
After doing some searching through the paleo and Crossfit forums, I learned that for a woman (that’s me), with hypothyroidism (me, again) doing Crossfit (yep), a very low carb diet, especially in the long-term, is not recommended. Apparently, the body thinks its starving, and starts to down-regulate thyroid production.
Then, with a high intensity workout, like Crossfit, it furthers stresses the body into “adrenal fatigue” (now being more accurately called hypocortisolism or HPA-axis dysfunction).
Of course, I don’t have any medical studies to back up these notions at this time. I’m still working on that. And there are some experts on ketogenic/VLC diets who say that the diet doesn’t actually down-regulate thyroid function. You just need less thyroid hormone when you are on it, and so thyroid levels look lower on blood tests.
Unfortunately, I don’t have time to weed through the medical literature and the debates. I don’t want to wait another day feeling pain in every single one of my muscles, feeling like I need a crane to get me out of bed, feeling like a ninety-year-old as I climb the stairs.