By: Justin Robinson, MA,RD,CSSD,CSCS,TSAC-F, Human Performanace Dietician, Naval Special Warfare Center
Posted: June 14, 2021
Information presented within is not intended to treat, cure, or prevent any disease or condition.

No particular diet plan is perfect for any Sailor, Naval Special Warfare (NSW) Candidate, or NSW Operator. Elements from any diet plan can improve performance, but no ideal “warfighter diet” exists. Nutrition must be individualized for optimal performance, health, and recovery.

The ketogenic (keto) diet is a very-low-carbohydrate, high-fat diet.  The diet plan limits total, daily carbohydrate intake to 25-50 grams, with a macronutrient breakdown of 5-10% carbohydrate, 15-20% protein, and 70-80% fat.  This differs significantly from low- or moderate-carbohydrate diet plans, such as the Paleo diet, since keto is based on macronutrients rather than categories of foods.

Keto proponents tout the plan’s ability to facilitate rapid weight and fat loss, while also improving concentration and curbing hunger.  While opponents argue that the plan contains too much total and saturated fat and too little fiber.


The brain can only use two sources of energy – glucose (blood sugar) and ketones.  When someone consumes very small amounts of carbohydrates (<50 grams in a day) blood glucose decreases, so the liver converts fat into ketones (creating a state of ketosis to keep the brain fueled).  Ketosis is essentially a survival mechanism and the keto diet was, in fact, developed as a “starvation-mimicking” diet.  The diet does often lead to weight and fat loss, as calorie intake may decrease without controlling portions or counting calories (primarily due to appetite suppression).

With few restrictions on the quality of food that can be consumed, a keto diet plan may or may not provide optimal nutrient intake. Someone can consume either the “butter and bacon” or the “spinach and olive oil” version … meaning that the keto diet plan can be completely void of nutrients OR a nutrient-dense plan with healthy fat intake.  The true challenge of the plan is sustainability – as controlling amounts of carbohydrate requires constant meal planning and preparation.


Each of the following contains ~50 grams of carbohydrate – thus, this would be the entire carbohydrate intake for an entire day on the keto diet:

  1. Cooked rice, pasta, oats, mashed potatoes: 1 1/2; Cups
  2. Cereal: 2 Cups
  3. Dried fruit: 1/2 Cup
  4. Fruit juice: 14oz
  5. Whole fruit: 2 large pieces

Typical carb-heavy foods are not the only source of carbohydrate intake.  Additional carbohydrate-containing foods:

  1. Almond butter: 7 grams/2 Tbsp
  2. Beef jerky: 8 grams/oz
  3. Cashews: 9 grams/2 Tbsp
  4. Milk: 15 grams/8 oz
  5. Starchy vegetables (carrots, peas, corn): 15 grams 1/2 Cup


Many individuals believe they are following a ketogenic diet but consume too much protein to allow for ketosis.  With reduced-carbohydrate intake, the liver also converts protein into glucose – therefore high protein intake can block ketone production.  To follow a true ketogenic diet, protein intake should not exceed 20% of total Calories (100-150 grams, for most).

Pros & Cons

Reasons to consider the keto diet … the ketogenic diet has the potential to:

  1. Increase weight loss
  2. Improve symptoms of certain disorders, such as epilepsy*
  3. Improve symptoms of some forms of cancer*
  4. Improve post-concussive symptoms*
  5. Decrease chronically high blood glucose levels*
  6. Decrease oxygen toxicity risk during diving*

*The ketogenic diet is not medical treatment – always consult a physician.

Reasons NOT to try the keto diet …

  1. Because it worked for someone else (especially if that someone is a social media influencer or a friend of a friend)
  2. During periods of high-energy output (such as NSW Student pipeline training)
  3. Participation in high-intensity or interval-based sports (such as basketball, football, lacrosse, track & field)
  4. During periods of growth (e.g. children, young adults, pregnancy)
  5. Inability to plan and prepare all your meals or frequent travel (such as living in the barracks or at a training detachment)


In terms of lipid profile (cholesterol levels), the jury is still deliberating.  Research has revealed both positive and negative cardiovascular risk factor changes from ketogenic diet trials.  Thus, it benefits some people while impairs others.  Talk to a physician or Registered Dietitian if you have ever had borderline or high cholesterol (dyslipidemia).


In 2019, an article circulated stating that the military (Strategic Operations Command (SOCOM), specifically) was planning to mandate the ketogenic diet … this was 100% false information.  The NSW Human Performance Program component of SOCOM understands the variable and fluid physical requirements of Special Operations Forces selection, training, and deployment.  Thus, the “optimal” diet plan differs and changes throughout Selection and Training and Inter-Deployment Training Cycles. 

Therefore, it is extraordinarily unlikely that any diet plan will ever be promoted or mandated at the Department of Defense or SOCOM levels.


As you will read in several nutrition blog posts, no one should demonize any food or food group.  Thus, carbohydrates are not the enemy.  Carbohydrate-based foods are delicious and easy to over consume … thus, if weight loss the goal, someone may benefit from decreasing carbohydrate intake.  But a recommendation to “reduce your carbs” should not translate to “go on a keto diet”.

The keto diet CAN be a healthy eating plan, but is difficult to sustain and likely will provide insufficient fuel for NSW candidates.


Naval Special Warfare Assessment Team