Retrospective #216: Is Low-Carb High-Protein or High-Fat?

The cognoscenti (my regular readers, who are “in-the-know”) know that the answer is “high-fat.” But I squirm in my seat when I hear someone, who appears to be informed on the subject, say, “Low Carb is high-protein.”

That occurred one night in while I was watching one of my favorite TV shows. The subject was a Wall Street Journal “Saturday Essay,” titled, “The Questionable Link Between Saturated Fat and Heart Disease.” This person accurately blamed the obesity epidemic on the American (or Western) diet which is very high in carbs and processed foods; but then he proceeded instead to advocate for a diet high in protein! That is WRONG, WRONG, WRONG!

Diets that are very high in carbohydrates and processed foods ARE the reason we as a civilization for 50 years have been getting fatter and sicker.  The Wall Street Journal got it right. They also correctly noted that the beginning of this very large, population-wide, public health “experiment” in eating “low-fat” can be attributed to Ancel Keys. I first wrote about Keys in Retrospective #3, after Gary Taubes (Retrospective #5) brought him to my attention.

Keys was an American physiologist whose “Six Nation Study” (later revised to “Seven Country Study”) was just bad science. This was just a few years after President Eisenhower had his heart attacks and went on the Pritikin diet. Incredibly, however, low-fat quickly became dietary dogma. Keys made the cover of Time Magazine in 1961 and joined the American Heart Association board. It was later revealed that his studies were “cherry picked.”

Meantime, a low-carb diet, which is the antidote to the fattening low-fat diet (you read that right), is high fat and moderate protein. Let’s talk numbers (percentages). Diets can be classified by what are called Macronutrient Ratios:

The Low Fat Diet: The Standard American Diet (SAD, for short!) is high carb, moderate fat and adequate but low protein. The FDA’s Nutrition Facts Panel on processed foods, based on a 2,000 calorie a day diet, is comprised of 60% carbs, 30% fat and 10% protein. The dietary Dictocrats have recently recognized that simple sugars and processed carbs are too high and have moved slightly away from the 60% carb percentage (but not changed the package labeling). Still, they steadfastly maintained a target of less than 30% fat. That can only mean an increase in protein. To the extent carbs are reduced (from 60%) and fats do not exceed 30% (while advocating a lower percentage), only protein can rise. Remember, there are only three macronutrients: carbs, fat and protein. Something’s gotta go up!

In addition, a plant-based diet is increasingly being advocated by the vegan lobby. All plants are carbohydrates. Most protein (not all – there are some proteins in legumes and nuts) is animal-based. So, the struggle to maintain a high-carb, low-protein macronutrient ratio is an unrelenting battle within the establishment.

The Low Carb Diet: The macronutrient ratios for a low-carb diet are not defined. They are all over the place. This is okay with me since 1) people’s metabolic status (degree of carbohydrate intolerance) are different and 2) making the transition from 60% carb to a much lower percentage is a very good thing – but for some (who don’t go “cold turkey” like me), it takes time and a lot of effort. So, let’s say for our purposes that a prototypical Low Carb diet is 20% carb, 20% protein and 60% fat. That’s a very dramatic (2/3rds) reduction in carbs, from 60% to 20% (low), and a doubling of protein from 10% to 20% (moderate) and fat, from 30% to 60% (high). That “high fat” is really scary for some people, especially because there is disagreement (and therefore confusion among the public) about what “good” fats are.

For that discussion, Google “the nutrition debate good fats” for some of my columns on fat. But there is another mitigating factor: All these percentages are in calories, and since fat has more than twice as many calories per gram as both protein and carbohydrates (9 vs. 4), you really are eating less than half as much fat (by weight) than you think.

Very Low Carb: I started “Low Carb” dieting at 20 grams a day, which is Very Low Carb: My first ratios (as it turned out) were 10% carb, 30% protein and 60% fat. I later tweaked that to 7% carb, 25% protein and 68% fat. Today, I aspire to eat 5% carb, 20% protein and 75% fat (by calorie, remember, not weight). Of course, we don’t eat percentages; we eat portions, which are envisioned in the mind’s eye by mass (weight). These quantities and calorie percentages are determined by software that some of the compulsive among us (including me) have used.

Low Carb is really moderate protein and high fat. The lower the carb percentage, the higher the fat. Some call it, Low Carb High Fat (LCHF). What does your Eating Plan look like?