The U.S. dietary guidelines were launched in 1980. 1 As revealed by investigative journalist Nina Teicholz, 2 , 3 the first guidelines were written by a single U.S. Senate committee staffer, Nick Mottern, who was heavily influenced by a professor of nutrition at the Harvard School of Public Health, and that first edition laid the groundwork for decades of flawed advice.
In 1965, Americans ate about 40 percent of their calories as carbohydrates and another 40 percent of their calories came from fat. 4 The original 1980 guidelines called for a diet lower in fat and higher in carbohydrates, and by 2010, Americans had reduced their fat consumption to 35 percent, and increased carbohydrates to 55 in to 65 percent, based on the USDA's report on dietary guidelines for Americans. 5
The advice to eat less fat and more carbs — primarily in the form of grains —has been followed ever since, and the results of this kind of diet are clear for everyone to see.
Conventional Dietary Guidelines Are a Recipe for Obesity and Ill Health
Nearly 40 percent of American adults, over 18 percent of teens and nearly 14 percent of young children are now obese, not just overweight. Nearly 8 percent of adults are severely obese. 6
Half of all Americans also have prediabetes, diabetes or other chronic illness, 7 and some of the evidence suggests 80 percent of the U.S. population already have "diabetes in situ," meaning they're prediabetic, 8 even if their fasting glucose is normal. One in 5 deaths is obesity-related 9 and 1 in 3 women and half of all men will develop some form of cancer in their lifetime.
Incredibly, a recent report 10 by the Council for a Strong America (a group consisting of retired admirals and generals) reveals the obesity trend is also preventing the U.S. Army from reaching its recruitment goal. Overall, 71 percent of men and women aged 17 to 24 failed to qualify for basic service this year; 31 percent were disqualified due to obesity.
The "2015 Health Behaviors Survey: Health Promotion and Disease Prevention Among U.S. Active-Duty Service Members" report, 11 issued in 2018, reveals two-thirds of active military are also overweight or obese, including nearly 61 percent of the Marine Corps and nearly 70 percent of all active Army personnel, up from 13 percent in 2008. 12
While obesity is measured based on body mass index (BMI), which can be misleading when you have a lot of muscle (as muscle weighs more than fat), these percentages still reveal a major problem afoot, considering the body weight of our armed forces can hardly be blamed on lack of physical activity.
US Armed Forces Data Reveal Shocking Increase in Obesity
BMI was also used a decade ago, and aside from diet, there's no way to explain how the Army went from 13 percent overweight/obese personnel in 2008 to nearly 70 percent a mere decade later. Nor can you explain how we got here when, in 1995, the prevalence of overweight or obese personnel in the army was a mere 2 percent! 13
Army data also shows that fitness actually declines during military deployment, despite regimented diet and physical activity. 14 Just what kind of diet is recommended for active military?
Complex carbs, lean protein "and a moderate consumption of fat," is what the military eats, according to Army sources. 15 In other words, a diet higher in net carbs and lower in dietary fats. An even greater travesty, they recommend the unhealthiest of fats — "spreads" and margarine rather than pure butter. 16
Considering Army nutrition guidelines follow the U.S. dietary guidelines for Americans, is it any surprise that the armed forces are struggling with out-of-control obesity like the rest of the country? How much more proof do we need to realize that the nutritional guidelines are completely upside-down?
Based on the nutritional science now available, there's no doubt in my mind that a cyclical ketogenic diet is the answer — not just for people at large but also for our armed forces. A recent study again adds additional proof to this mounting evidence pile, showing that cutting carbs is a key strategy for improving your metabolism and maintaining a healthy weight.
More Evidence Low-Carb Diets Improve Metabolism
According to principal investigator Dr. David Ludwig, 17 professor of nutrition at Harvard School of Public Health and director of New Balance Foundation Obesity Prevention Center, the team's findings "suggest that what we eat — not just how much — has a substantial effect on our metabolism and thus how much weight we gain or lose."
The study, 18 published in the BMJ in November 2018, specifically looked at the effects of diets varying in carb-to-fat ratios on energy expenditure during weight loss maintenance. Once the 164 adults had lost 10 to 14 percent of their original weight on a calorie-restricted diet, they were then randomly assigned to one of three test diets for 20 weeks:
- 60 percent carbohydrates (high carb diet)
- 40 percent carbs (moderate)
- 20 percent carbs (low-carb diet)
Twenty grams of carbs a day is on the low end of what's typically recommended to maintain nutritional ketosis, although some may be able to eat up to 50 grams a day and still maintain a ketogenic state.
What they discovered here was that as carbohydrate ratios diminished, energy expenditure increased (meaning metabolism improved), prompting the team to conclude that low-carb diets "may improve the success of obesity treatment, especially among those with high insulin secretion." (For a review of and discussion about the strategy used to measure energy expenditure, see this Popular Science article. 19 )
High-Carb Diets Promote Weight Gain
On average, participants in the low-carb group burned 250 calories a day more than those in the high-carb group — a difference thought to produce a 20-pound weight loss within a few years' time, and possibly more, since cutting net carbs also tends to curb hunger and reduce overall food intake (an effect shown in other studies 20 ). In an article for the Los Angeles Times, Ludwig explains: 21
"The carbohydrate-insulin model 22 argues that overeating isn't the underlying cause of long-term weight gain. Instead, it's the biological process of gaining weight that causes us to overeat.
Here's how this hypothesis goes: Consuming processed carbohydrates (especially refined grains, potato products and sugars), causes our bodies to produce more insulin. Too much insulin … forces our fat cells into calorie-storage overdrive.
These rapidly growing fat cells then hoard too many calories, leaving too few for the rest of the body. So, we get hungry, and if we persist in eating less, our metabolism slows down …
The calories-in, calories-out view offers no compelling biological explanation for the obesity epidemic … But if the type of calories consumed affect the number of calories burned, this trend starts to make more sense.
The processed carbohydrates that flooded the food supply during the low-fat diet era of the last 40 years pushed the body weight set-point up across the population.
Our findings suggest that a more effective strategy to lose weight over the long term is to focus on cutting processed carbohydrates, not calories … Our study does not conclusively prove the carbohydrate-insulin model is true. But it credibly makes the case that all calories are not alike to the body. "
The High Cost of Being Wrong: Obesity Largely Responsible for Cancer and Heart Disease
The cost of dietary guidelines being wrong extend far beyond excess weight gain alone, as obesity is a primary culprit in rising cancer and heart disease rates. In "Obesity and Subtypes of Incident Cardiovascular Disease," published in the Journal of the American Heart Association, the authors note that: 23
"Obesity is a risk factor for various subtypes of cardiovascular disease (CVD), including coronary heart disease, heart failure and stroke …
Over a median follow‐up of 23 years … [a]fter adjustment for demographics, smoking, physical activity and alcohol intake, higher body mass index had the strongest association with incident heart failure among CVD subtypes, with hazard ratios for severe obesity of 3.74 for heart failure, 2.00 for coronary heart disease, and 1.75 for stroke … Weight management is likely critical for optimal heart failure prevention …"
Other recent research 24 sheds added light on how obesity causes cancer, showing that body fat clogs natural killer (NK) cells — cells that play a crucial role in destroying cancer cells — impeding their ability to function. Ultimately, the NK cells stop working, allowing cancer cells to proliferate. Dr. Leo Carlin with the Cancer Research UK Beatson Institute, who was not part of the study, commented on the results: 25
"This study reveals how fat molecules prevent immune cells from properly positioning their tumor-killing machinery, and provides new avenues to investigate treatments. A lot of research focuses on how tumors grow in order to find metabolic targets to stop them, so this is a reminder that we should consider the metabolism of immune cells too."
Becoming Metabolically Flexible Is the Key
What happens when you eat too many net carbs (total carbs minus fiber), too much protein and too little healthy fat? Over time, insulin resistance sets in, resulting in the gaining and retaining of unwanted body fat and the slow and steady deterioration of your mitochondrial function.
In short, for optimal health and fitness, your body must be able to burn fat for fuel, and this is an ability that is lost when you consume too many net carbs on a daily basis.
When your body is able to burn fat for fuel, your liver creates water-soluble fats called ketones that burn far more efficiently than carbs, thus creating far less damaging reactive oxygen species and secondary free radicals. Ketones also improve glucose metabolism and lower inflammation. 26
Importantly, when you lower your net carb ratio, the food group that needs to be increased is healthy fats, not protein.
Dietary fats — aside from being a healthy fuel source — are also vital for the health of your cellular membranes and play an important role in maintaining your body's electrical system, along with many other biological functions. For this reason alone, low-fat diets tend to do more harm than good.
Like other ketogenic diets, my metabolic mitochondrial therapy (MMT) diet detailed in " Fat for Fuel " is high in healthy fats and fiber and low in net carbs. However, it also stresses two specific strategies that many others fail to address, namely:
1. Moderating your protein intake to avoid overactivating mTOR, which plays a role in aging and cancer. Excessive protein can also be converted into body fat and, through some pathways, sugar. While net carb restriction normalizes the insulin pathway, protein restriction helps to normalize the mTOR pathway, both of which are important for optimal health and longevity.
2. Cycling in and out of ketosis once you've started burning fat as your primary fuel. To do this, all you need to do is increase your net carb and protein intake once or twice a week.
After a day or two of "feasting," you then cycle back into nutritional ketosis (high-fat, low net carb, moderate protein) for the remainder of the week. By periodically pulsing higher carb intakes, consuming 100 or 150 grams of carbs opposed to 20 to 50 grams per day, your ketone levels will dramatically increase and your blood sugar will remain consistently suppressed.
Needless to say, processed foods are not recommended. Eating real food is key no matter what your ratios of fat, carbs and protein are. Cooking from scratch using whole, unadulterated and ideally organic or biodynamically grown produce and grass fed animal products is really the only way to avoid a majority of harmful additives and contaminants that contribute to weight gain and ill health. Another key is to select the right fats.
Cyclical Ketogenic — One of the Most Effective Low-Carb Diets
It is easy to make the mistake of believing that you should be low-carb continuously. Many, including me, have made this mistake. However, it is important to understand that continuous low-carb, high-fat diets are only a useful short-term intervention that is used until you regain metabolic flexibility and can burn either fat or sugar for fuel.
Once you reach this state, as evidenced by your ability to generate ketones over 5 mmol/l in your blood, then it is important to reintroduce healthy carbs back into your diet. Sweet potatoes would be a great example. If you fail to do this, the health of your microbiome will likely suffer.
Additionally, many experts now believe that your body develops a resistance to the benefits of ketosis unless you regularly cycle in and out of it. An example is that your insulin level could drop below the level at which it inhibits the production of glucose by your liver (hepatic gluconeogenesis).
Even though you are eating virtually no carbs, your insulin level is so low that your liver is forced into making glucose to supply fuel to your brain. In this setting, the solution is to eat healthy carbohydrates that will raise your insulin levels. This will shut down liver glucose production and paradoxically actually lower your blood sugar.
Good Versus Bad Fats
While my latest book, "Superfuel," delves into the ins and outs of good and bad fats, as a general rule, the fats you want to eat more of are plant- and animal-based saturated fats which, contrary to popular myth, do NOT cause heart disease, as evidenced in a large number of studies. 27 , 28 , 29 , 30 , 31 , 32 In fact, just about any fat found naturally in food — whether animal- or plant-based — is in fact healthy for you.
The marine-based omega-3 fat docosahexaenoic acid (DHA) is particularly important, as it's not actually used for fuel; rather it's a building block and major structural element in most cells. You can learn more about this in my interview with my "Superfuel" coauthor, James DiNicolantonio, Pharm.D. Examples of healthy fats to eat more of include:
Olives and olive oil (look for third party certification, as 80 percent of olive oils are adulterated with vegetable oils. Avoid cooking with olive oil; use it cold)
Coconut oil (excellent for cooking as it can withstand higher temperatures without oxidizing)
Animal-based omega-3 fat from fatty fish low in mercury like wild caught Alaskan salmon, sardines, anchovies and/or krill oil
Butter made from raw grass fed organic milk
Seeds like black sesame, cumin, pumpkin and hemp seeds
Grass fed meats
Ghee (clarified butter); lard and tallow (excellent for cooking)
Organic, pastured eggs
The harmful fats you need to steer clear of are all man-made. This includes trans fats and all highly refined polyunsaturated vegetable oils, 33 , 34 which are high in damaged omega-6 and produce toxic oxidation products like cyclic aldehydes when heated.
When consumed in large amounts, omega-6 polyunsaturated fats — and especially industrially processed ones — also cannot be effectively burned for fuel. Instead, they're incorporated into cellular and mitochondrial membranes where they become susceptible to oxidative damage, which ultimately damages your metabolism.
How to Implement a Cyclical Ketogenic Diet
To implement a high-fat, low-carb ketogenic diet, begin by eliminating packaged, processed foods. It's important to eat real (whole) foods, plenty of healthy fats and, initially, as few net (nonfiber) carbs as possible. Foods to reduce or eliminate in this phase include all grains and any food high in sugar, particularly fructose, but also galactose (found in milk) and other sugars.
As a general rule, you'll want to reduce your net carbs to 20 to 50 grams a day or less, and restrict protein to 1 gram per kilogram of lean body mass. To make sure you're actually meeting your nutritional requirements and maintaining the ideal nutrient ratios, use an online nutrient tracker such as www.cronometer.com/mercola , which is one of the most accurate nutrient trackers available.
My tracker is actually preset for nutritional ketosis, so based on the base parameters you enter, it will automatically calculate the ideal ratios of net carbs, protein and healthy fats required to put you into nutritional ketosis. This is what will allow your body to start burning fat as its primary fuel rather than sugar, which in turn will help optimize your mitochondrial function, metabolism and overall health and fitness.
Remember, once you are able to generate ketones over 0.5 mmol/l in your blood, that is the time to start reintroducing carbs cyclically back into your diet. Typically, a few times a week works just fine. Ideally this is done on strength training days on which you actually increase your protein intake.