Rigorous physical training is a daily feature of military life, and yet the Military Times warns that the armed forces face a "huge problem with obesity" that is "only getting worse." Maybe you've seen the headlines: "Too Fat to Fight , " or, closer to home, "Texas kids physically unfit for military, " b ut you probably don't know the full extent of the problem.

Texas is among the states having the hardest time finding fit recruits. Obesity rates are higher than the national average, and poor fitness is leading to more injuries and fewer recruits ready for service.

How can it be? The answer is that nutrition, and not physical activity level, is the most important driver of weight. And with one in every 13 troops obese, costing the Pentagon an estimated $1 billion per year in added health care costs, according to the Military Times, the U.S. military is in desperate need of a more effective diet.

After 21 years in Special Operations, I know firsthand the need to be in top physical condition. Your body has to be able to take a considerable amount of pounding just to complete the long training pipeline required to become a Special Operator. Finding qualified candidates has become increasingly difficult due to the degenerating physical abilities of youth. I've seen potential candidates who eat a diet high in carbohydrates, especially sugar, perform well below the standard. But I've also seen that when a motivated candidate makes a diet change to a low-carb/high-fat way of eating, there is always a change in body composition and improvement in performance.

In many ways, the military's situation is a reflection of the broader American obesity epidemic, caused by years of misguided and even dangerous "expert" dietary advice that has shaped not only the mealtime decisions of ordinary Americans but the recommendations of nearly all nutritionists, dietitians and medical doctors, including those in the military.

That advice, driven by the government's Dietary Guidelines for Americans, has largely stuck to the familiar low-fat, high-carbohydrate diet that calls on us to cut meat, butter and cheese. Yet in recent years, the science has evolved, and it has become increasingly clear to people like me that fats aren't the enemy. Indeed, as I ate more fat and reduced my intake of sugars and other carbohydrates like grains, I lost weight and became healthier.

Experiences like mine are now backed by a fast-growing body of science, showing carbohydrate restriction to be effective for fighting obesity and diabetes while improving most heart-disease risk factors.

For many, it's hard to get past the basic assumption that the fat on your plate becomes the fat in your body. But the truth is that it's excessive carbohydrates that turn into body fat -- completely contrary to what Americans have long been told.

So why hasn't the government's dietary advice caught up to the science? According to a rigorous investigation in The BMJ on the dietary guidelines, the experts appointed to review the scientific evidence relied on weak scientific standards in their report and failed to review the most recent science on a number of topics, including optimal intakes for carbohydrates, saturated fat and salt. Most critically, the report relied heavily on observational studies in which researchers follow test groups over long periods of time. But even the best epidemiological studies, according to the BMJ, "suffer from a fundamental limitation. At best they can show only association, not causation. Epidemiological data can be used to suggest hypotheses but not to prove them." This is science 101.

The U.S. military serves more than 150 million meals per year to its personnel, and when those meals are based on a government-advised, high-carbohydrate diet, our troops have a harder time staying trim and healthy. The Army's own website warns people to stay away from high-fat meats, egg yolks and whole milk and advises "eating less fatty food for better overall health," while encouraging a diet that includes pasta and bread. Making matters worse, service members usually have fewer options for avoiding these nutritional mistakes, especially on deployments when they often can't cook their own meals.

The government must get it right in the next round of guidelines so that our troops get the nutrition that will make them fit and ready to serve. Otherwise, the dangerous trajectory of less-healthy service members and unfit recruits will only get worse.

Steve Barrons is a retired U.S. Air Force Special Operations Combat Controller and a certified personal trainer and ketogenic diet specialist.

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