Read The Primal Blueprint Online
Authors: Mark Sisson
Here are more details about how carbohydrates impact the human body and the degree to which we need them, or don’t need them, in our diet. Carb intake level is the decisive factor in your weight-loss success or failure, and excessive carb consumption is arguably the most destructive behavior disparity between ourselves and what our genes crave to support health, longevity, and peak performance. Eliminating grains and sugars from your diet could be the number one most beneficial thing you ever do for your health!
0 to 50 grams per day
Ketosis and Accelerated Fat Burning
Acceptable for occasional one- to two-day Intermittent Fasting efforts toward aggressive weight loss (or longer term, for medically supervised weight-loss programs for the obese and/or type 2 diabetics), provided adequate protein, fat, and supplements are consumed. Excellent catalyst for quick, relatively comfortable weight loss and not at all dangerous. (Grok relied heavily on fat metabolism and ketosis to account for the difficulty in obtaining appreciable amounts of carbs in daily life.) Not recommended as a long-term practice for most people due to resultant deprivation of high-nutrient-value vegetables and fruits.
50 to 100 grams per day
Primal Sweet Spot for Effortless Weight Loss
Minimizes insulin production and accelerates fat metabolism. By meeting average daily protein requirements (in grams per pound of lean mass, as detailed previously), eating nutritious vegetables and fruits, and staying satisfied with delicious high-fat foods (meat, fish, eggs, nuts, seeds), you can lose one to two pounds of body fat per week in the “sweet spot.” Delicious menu options that land in the sweet spot are detailed in
Chapter 8
.
100 to 150 grams per day
Primal Blueprint Maintenance Range
Allows for genetically optimal fat burning, muscle development, and effortless weight maintenance. Rationale supported by humans eating and evolving in this range or below for millions of years. Dietary emphasis of vegetables, fruits, nuts, seeds, and animal foods, with grains and processed sugars eliminated.
A prior history of heavy carb intake may result in a brief period of discomfort during the transition to
Primal Blueprint
eating. Adequate consumption of satisfying foods (high-water-content fruits and vegetables, high-fat snacks like nuts and seeds, and meals emphasizing animal foods) helps protect against feeling deprived or depleted.
150 to 300 grams per day
Steady, Insidious Weight Gain
Continuous insulin-stimulating effects prevent efficient fat metabolism and contribute to widespread health conditions. The de facto recommendation of many popular diets and health authorities—including the USDA Food Pyramid!—is 150 to 300 grams per day, despite clear danger of developing Metabolic Syndrome. Chronic exercisers and active growing youth may eat at this level for an extended period without gaining fat, but eventually fat storage and/or metabolic problems are highly probable.
This “insidious” zone is easy to drift into, even by health-conscious eaters, when grains are a dietary centerpiece, sweetened beverages or snacks leak into the picture here and there, and obligatory fruits and vegetables are added to the total. Recall that Wendy Korg’s trip to Jamba Juice for a healthy afternoon snack resulted in 187 grams of carbs ingested at one sitting. Starting your day off with a bowl of muesli cereal, a slice of whole wheat toast, and a glass of fresh orange juice might seem as healthy as can be—but the numbers start racking up (that’s 97 grams right there!), and the disastrous insulin-sugar crash-stress response cycle is set in motion. Despite trying to do the right thing and cut fat and calories, many frustrated people still gain a pound or two of fat per year for decades as a result of the carb intake in the insidious range.
300 or more grams per day
Danger Zone
!
The zone of the average American’s diet, and in excess of official USDA dietary guidelines (which suggest you eat 45 percent to 65 percent of calories from carbs), thanks to stuff like soda tipping the scales over. Extended time in the danger zone results in almost certain weight gain and Metabolic Syndrome. The danger zone is the primary catalyst for the obesity and type 2 diabetes epidemics, as well as numerous other significant health problems. Immediate and dramatic reduction of grains and other processed carbs is critical.
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Despite trying to do the right thing and cut fat and calories, many frustrated people still gain a pound or two of fat per year for decades as a result of carb intake in the insidious range
.
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I’ve already discussed how the common admonition to keep dietary fats low is truly unfounded in most credible research. As far as I’m concerned, fat is your friend. Consuming healthy fats from animal and plant sources supports optimal function of all the systems in your body. Furthermore, ingesting fat helps you feel full and satisfied in a way that carbohydrates cannot. Because fat has little or no impact on blood glucose levels and insulin production and takes far longer to metabolize than carbohydrates, you will feel a deep and long-lasting satisfaction from consuming ample amounts of fat in your diet.
I understand that this is a controversial topic that will be met with some opposition. Please take it upon yourself to gain a clear understanding of the issue, learn to distinguish healthy fats from unhealthy, and sort out misleading Conventional Wisdom that frowns upon food staples that drove human evolution. The highly respected Nurses’ Health Study, tracking dietary habits of 127,000 nurses over two decades (the largest epidemiological study of women in history, it has led to the publication of 265 scientific papers in leading journals), showed no statistically significant association between total fat intake (or cholesterol intake) and heart disease. Many other studies have attempted to establish a firm connection, yet none have demonstrated that a high-fat diet by itself causes heart disease. So how can it be that low-fat eating became the Conventional Wisdom? I believe that the otherwise well-meaning, well-educated folks in the low-fat camp are influenced by a few factors that lead them to the party line conclusion that a high-fat diet is unhealthy.
1. Failure to distinguish between good fats and bad fats
. The skyrocketing rates of obesity, heart disease, and cancer that have ensued over the past half-century from consuming high-fat processed foods have unfairly implicated all fats as dangerous. As I discussed earlier and will cover further in the next chapter, the typical modern diet is grossly imbalanced between omega-6 fats and omega-3 fats. We ingest way too much of the former (from processed foods, partially hydrogenated vegetable oils, and grain-fed animal products) and way too little of the latter (from organic meats, eggs, and fish, and certain nuts, seeds, and omega-3 oils).
Furthermore, we consume excessive amounts of the highly toxic partially hydrogenated fats and trans-fats (they are not quite the same but are closely related and both evil). These “Franken-fats” are created by heating and chemically treating vegetable and seed oils to render them solid, effectively extending shelf life and improving the flavor of processed foods. They are easily oxidized to form free radical chain reactions that damage cell membranes and body tissue, and compromise immune function. Because your brain, nervous system, and vascular system are primarily composed of membranes,
any dysfunction in these critical areas can be devastating. Research confirms that consumption of trans-fatty acids and partially hydrogenated fats may promote inflammation, aging, and cancer. The
New England Journal of Medicine
reviewed numerous studies and reported a strong link between processed fat consumption and heart disease.
2. Carbs making fat “look bad.”
Fat is calorically dense at nine calories per gram. If you consume excessive carbs (150 to 300 grams or more per day), produce a high level of insulin, and eat any appreciable amount of fat along with your high-carb diet, yes, your fat intake will contribute directly to making you fat. You know the saying “Which came first, the chicken or the egg?” Well, in this case, it’s neither the chicken nor the egg making you fat—it’s the carbs! High levels of insulin direct both carbs and fat (and protein) into your fat cells. Limit your carbs and fat will make you healthy, help moderate your appetite and total caloric intake, and greatly enhance the satisfaction level of your diet.
“
Which came first, the chicken or the egg? In this case, neither. It’s the carbs that make you fat!
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3. Propaganda and flawed science manipulated into Conventional Wisdom
. The machinations of public policy bureaucracy often leave rational thinking in the dust in favor of protecting and promoting corporate interests and the reputations of politicians. While I am all in favor of capitalism, it’s unsettling how much decision-making power is controlled by corporations that spend billions of marketing dollars molding and shaping Conventional Dietary Wisdom in the direction of profits, with little regard for health.
The story of how saturated fat came to be vilified should mention the work of American scientist Ancel Keys. Keys was an eloquent and dynamic early promoter of the link between saturated fat intake, cholesterol levels, and heart disease—a driving force in the origination and promotion of the lipid hypothesis of heart disease mentioned earlier. Keys received notoriety in the 1960s for his efforts to transition the public away from saturated fats to replacements like polyunsaturated oils or low-fat eating in general. It has taken decades, at a dawdling pace, to recognize the folly of his health suggestions. For example, Keys didn’t even connect obesity to heart disease risk, and the foundation of his work was compromised when he was criticized for hand-picking examples (comparisons of fat intake and heart disease rates among different cultures) that supported his hypotheses. In fairness, Keys later did some great work helping to popularize the Mediterranean diet (highlighted by the liberal intake of healthy fats), even spending his last few decades living in a small town in Italy and studying the residents’ dietary habits.
On a bureaucratic level, the U.S. government has time and again shown a penchant for doggedly defending the status quo and vigorously squashing voices opposing Conventional Wisdom. A sordid example of the influence of power and money on the development of public policy is found in the FDA’s so-called imitation policy, passed in 1973 (without Congressional approval, thanks to some clever legal maneuvering). The legislation relieved food manufacturers from having to use that pesky “imitation” designation on labels of foods created with artificial ingredients (coffee creamers, imitation egg mixes, processed cheeses, whip cream, and hundreds more), as long as manufacturers added synthetic vitamins to their concoctions to approximate the benefits of similar whole foods.
Mary Enig, Ph.D., a renowned nutritionist, lipid biochemistry expert, and author of
Know Your Fats
, from the University of Maryland, has spent a career battling Conventional Wisdom’s position take on fat intake and heart disease. In the 1970s she was a central figure in challenging the corruption and misinformation dispensed by the USDA and the U.S. Senate’s McGovern Committee (headed by former presidential candidate George McGovern). Influenced by highly questionable, lobbyist-tainted testimony, the committee published its report (many believe McGovern was hoodwinked by subordinates to buy into flawed conclusions) directing Americans to replace saturated fat with PUFAs and to limit fat intake in general (which was then disastrously replaced with excessive carbohydrates).
Ensuing government-funded research was essentially mandated to fall in line with the committee recommendations, and the notion that fats are bad took hold and flourished into Conventional Wisdom for decades (and is still going strong!). The discussion of the food propaganda topic is compelling enough to fill entire books (check out
Fast Food Nation, Food Politics, Appetite for Profit
, and
Good Calories, Bad Calories
for fascinating and detailed examinations of how Conventional Wisdom has led us astray), so we’ll wrap here by asserting the point that it’s clearly unwise to blindly trust Conventional Wisdom when it comes to fat and to dietary habits in general.
By now you know that we evolved to burn primarily fats and a little glucose. We can also burn protein, when certain amino acids enter the energy pathways through a part of the glucose cycle (as happens when we run out of glucose or glycogen during a long workout or during starvation). Protein can also be converted to glucose in the liver. While most cells in our body can easily burn both fats and glucose, there are a few select cells that function only on glucose (some brain cells, red blood cells, and kidney cells, for example). Without glucose, those cells would cease to function and we would not last very long. The minimum daily glucose requirement to keep those systems running
has been estimated at between 150 and 200 grams per day, but recent research shows that after a little adaptation, some of these cells can operate effectively on a fuel known as ketones, further reducing the overall glucose requirement.
Ketosis was crucial to our evolution. As we have already discussed here, our ancestors didn’t always have access to a handy-dandy daily supply of glucose-containing carbohydrates like we do today. In fact, they may have gone weeks or months without appreciable carbs, so they had to evolve a system whereby the liver could take protein either from the muscles or directly from the diet and convert it into glucose through gluconeogenesis. This system worked to keep Grok alive during short periods of starvation or longer periods when meat (protein and fats) was plentiful but plants (carbs) were not. Today we can tap into this same system and prompt our genes to speed up the process of fat loss when we cut carbs while still consuming adequate dietary protein. In this scenario, we never have to sacrifice muscle in pursuit of fat loss (the unfortunate M.O. for traditional calorie-restriction weight loss) if we eat according to the
Primal Blueprint
. And the best part of all this is that gluconeogenesis tends to “waste” fat in the process.